Add LiPo battery monitoring with ESP-NOW cache and dashboard API.

Slaves report pack voltages every 30s; the master caches them for fast
BATTERY_STATUS reads. goTool exposes REST/WebSocket and shows values in
the dashboard, with a nanopb fix so optional lipo submessages encode.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/README.md

@@ -87,7 +87,7 @@ Polling runs only when at least one connection has `receive_accel: true` **and**
 **Hello** (on connect; accel is off until `set_stream`):
 
 ```json
-{"type":"hello","serial_port":"/dev/ttyUSB0","interval_ms":16,"commands":["set_stream","get_stream","set_accel_stream","get_accel_stream","set_led_ring"]}
+{"type":"hello","serial_port":"/dev/ttyUSB0","interval_ms":16,"commands":["set_stream","get_stream","set_accel_stream","get_accel_stream","set_led_ring","get_battery"]}
 ```
 
 **Receive accel on this connection** (optional `interval_ms`, default from `-accel-interval`):
@@ -167,7 +167,7 @@ The dashboard can configure nodes using the same UART commands as the CLI:
 | Alle Slaves | per-slave ESP-NOW (Master bleibt unverändert; CLI `-all` setzt auch den Master) |
 | Unicast test | `unicast-test -client ID` |
 
-HTTP API (used by the web UI): `GET/POST /api/deadzone`, `GET/PUT /api/clients/{id}/accel-stream`, `POST /api/accel-stream` (legacy / `all_clients`), `POST /api/led-ring`, `POST /api/unicast-test`, `POST /api/find-me`, `POST /api/restart`, `POST /api/ota` (multipart field `firmware`, max 2 MiB).
+HTTP API (used by the web UI): `GET/POST /api/deadzone`, `GET/PUT /api/clients/{id}/accel-stream`, `POST /api/accel-stream` (legacy / `all_clients`), `GET/POST /api/battery`, `POST /api/led-ring`, `POST /api/unicast-test`, `POST /api/find-me`, `POST /api/restart`, `POST /api/ota` (multipart field `firmware`, max 2 MiB).
 
 **LED ring** (`POST /api/led-ring` and WebSocket `set_led_ring` on `:8081`):
 
@@ -179,6 +179,16 @@ HTTP API (used by the web UI): `GET/POST /api/deadzone`, `GET/PUT /api/clients/{
 
 Modes: `clear`, `color` (full ring), `progress` (0–100), `digit` (0–10 symbols), `blink`, `find-me`. Use `client_id` (0 = master), or `all_clients` (+ optional `slaves_only`) for broadcast.
 
+**Battery** (`GET/POST /api/battery`, WebSocket `get_battery` on `:8081`):
+
+```json
+{"all_clients":true}
+{"client_id":0}
+{"client_id":16}
+```
+
+Response: `samples[]` with `client_id`, `lipo1`/`lipo2` (`valid`, `voltage_mv`, `percent`), `age_ms`. Slaves push to the master every **30 s**; UART reads the cache (fast). Dashboard polls with `all_clients`.
+
 **Accel stream per slave** (must be enabled before values appear; goTool polls only while at least one slave has stream on):
 
 ```http

goTool/api_battery.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"strconv"
+)
+
+func mountBatteryAPI(mux *http.ServeMux, link *managedSerial) {
+	mux.HandleFunc("/api/battery", func(w http.ResponseWriter, r *http.Request) {
+		switch r.Method {
+		case http.MethodGet:
+			serveBatteryGet(w, r, link)
+		case http.MethodPost:
+			serveBatteryPost(w, r, link)
+		default:
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		}
+	})
+}
+
+func serveBatteryGet(w http.ResponseWriter, r *http.Request, link *managedSerial) {
+	req := batteryAPIRequest{}
+	if v := r.URL.Query().Get("all_clients"); v == "1" || v == "true" {
+		req.AllClients = true
+	}
+	if s := r.URL.Query().Get("client_id"); s != "" {
+		id, err := strconv.ParseUint(s, 10, 32)
+		if err != nil {
+			writeJSON(w, http.StatusBadRequest, batteryAPIResponse{Error: "invalid client_id"})
+			return
+		}
+		req.ClientID = uint32(id)
+	} else if !req.AllClients {
+		req.AllClients = true
+	}
+	out := applyBatteryStatus(link, req)
+	status := http.StatusOK
+	if out.Error != "" || !out.Success {
+		status = http.StatusServiceUnavailable
+	}
+	writeJSON(w, status, out)
+}
+
+func serveBatteryPost(w http.ResponseWriter, r *http.Request, link *managedSerial) {
+	var body batteryAPIRequest
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeJSON(w, http.StatusBadRequest, batteryAPIResponse{Error: "invalid JSON"})
+		return
+	}
+	if !body.AllClients && body.ClientID == 0 {
+		body.AllClients = true
+	}
+	out := applyBatteryStatus(link, body)
+	status := http.StatusOK
+	if out.Error != "" || !out.Success {
+		status = http.StatusServiceUnavailable
+	}
+	writeJSON(w, status, out)
+}

goTool/api_serve.go

@@ -70,6 +70,7 @@ type otaAPIResponse struct {
 func mountServeAPI(mux *http.ServeMux, link *managedSerial, hub *wsHub, streamCtl *accelStreamCtl) {
 	mountAccelStreamAPI(mux, link, hub, streamCtl)
 	mountLedRingAPI(mux, link)
+	mountBatteryAPI(mux, link)
 	mux.HandleFunc("/api/deadzone", func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case http.MethodGet:

goTool/api_stream.go

@@ -133,7 +133,8 @@ func (h *accelStreamHub) register(conn *websocket.Conn, portName string) *wsSubs
 		Serial:     portName,
 		IntervalMs: int(h.defaultInterval / time.Millisecond),
 		Commands: []string{
-			"set_stream", "get_stream", "set_accel_stream", "get_accel_stream", "set_led_ring",
+			"set_stream", "get_stream", "set_accel_stream", "get_accel_stream",
+			"set_led_ring", "get_battery",
 		},
 	}
 	if data, err := json.Marshal(hello); err == nil {
@@ -319,6 +320,15 @@ func writeStreamStatus(conn *websocket.Conn, msg StreamStatusMessage) {
 	_ = conn.WriteMessage(websocket.TextMessage, data)
 }
 
+func writeBatteryStatus(conn *websocket.Conn, out batteryAPIResponse) {
+	out.Type = "battery_status"
+	data, err := json.Marshal(out)
+	if err != nil {
+		return
+	}
+	_ = conn.WriteMessage(websocket.TextMessage, data)
+}
+
 func writeLedRingStatus(conn *websocket.Conn, out ledRingAPIResponse) {
 	out.Type = "led_ring_status"
 	data, err := json.Marshal(out)
@@ -416,10 +426,21 @@ func handleAccelWSCommand(conn *websocket.Conn, sub *wsSubscriber, data []byte,
 		}
 		writeLedRingStatus(conn, applyLedRing(link, body))
 
+	case "get_battery":
+		var body batteryAPIRequest
+		if err := json.Unmarshal(data, &body); err != nil {
+			writeBatteryStatus(conn, batteryAPIResponse{Error: "invalid JSON"})
+			return
+		}
+		if !body.AllClients && body.ClientID == 0 {
+			body.AllClients = true
+		}
+		writeBatteryStatus(conn, applyBatteryStatus(link, body))
+
 	default:
 		writeStreamStatus(conn, StreamStatusMessage{
 			Type: "stream_status",
-			Error: "unknown type (set_stream, get_stream, set_accel_stream, get_accel_stream, set_led_ring)",
+			Error: "unknown type (set_stream, get_stream, set_accel_stream, get_accel_stream, set_led_ring, get_battery)",
 		})
 	}
 }
@@ -478,6 +499,7 @@ func runAPIServer(portName string, link *managedSerial, addr string, defaultInte
 	mux := http.NewServeMux()
 	mountExternalAPI(mux, portName, defaultInterval, hub, link, dash, ctl)
 	mountLedRingAPI(mux, link)
+	mountBatteryAPI(mux, link)
 
 	srv := &http.Server{Addr: addr, Handler: mux}
 	go func() {

goTool/battery_api.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"powerpod/gotool/pb"
+)
+
+const (
+	lipoMinMv = 3000
+	lipoMaxMv = 4200
+)
+
+type lipoReadingJSON struct {
+	Valid     bool   `json:"valid"`
+	VoltageMv uint32 `json:"voltage_mv"`
+	Percent   int    `json:"percent,omitempty"`
+}
+
+type batterySampleJSON struct {
+	ClientID uint32          `json:"client_id"`
+	Lipo1    lipoReadingJSON `json:"lipo1"`
+	Lipo2    lipoReadingJSON `json:"lipo2"`
+	AgeMs    uint32          `json:"age_ms,omitempty"`
+}
+
+type batteryAPIRequest struct {
+	ClientID   uint32 `json:"client_id"`
+	AllClients bool   `json:"all_clients"`
+}
+
+type batteryAPIResponse struct {
+	Type     string              `json:"type,omitempty"` // battery_status (WebSocket)
+	Success  bool                `json:"success"`
+	Samples  []batterySampleJSON `json:"samples,omitempty"`
+	Error    string              `json:"error,omitempty"`
+}
+
+func lipoPercent(mv uint32) int {
+	if mv <= lipoMinMv {
+		return 0
+	}
+	if mv >= lipoMaxMv {
+		return 100
+	}
+	return int((mv - lipoMinMv) * 100 / (lipoMaxMv - lipoMinMv))
+}
+
+func lipoFromPBMsg(l *pb.LipoReading) lipoReadingJSON {
+	if l == nil {
+		return lipoReadingJSON{}
+	}
+	return lipoFromPB(l.GetValid(), l.GetVoltageMv())
+}
+
+func lipoFromPB(valid bool, mv uint32) lipoReadingJSON {
+	out := lipoReadingJSON{Valid: valid, VoltageMv: mv}
+	if valid {
+		out.Percent = lipoPercent(mv)
+	}
+	return out
+}
+
+func batterySamplesFromPB(samples []*pb.BatterySample) []batterySampleJSON {
+	out := make([]batterySampleJSON, 0, len(samples))
+	for _, s := range samples {
+		out = append(out, batterySampleJSON{
+			ClientID: s.GetClientId(),
+			Lipo1:    lipoFromPBMsg(s.GetLipo1()),
+			Lipo2:    lipoFromPBMsg(s.GetLipo2()),
+			AgeMs:    s.GetAgeMs(),
+		})
+	}
+	return out
+}
+
+func applyBatteryStatus(link *managedSerial, in batteryAPIRequest) batteryAPIResponse {
+	resp, err := link.BatteryStatus(&pb.BatteryStatusRequest{
+		ClientId:   in.ClientID,
+		AllClients: in.AllClients,
+	})
+	if err != nil {
+		return batteryAPIResponse{Error: err.Error()}
+	}
+	samples := batterySamplesFromPB(resp.GetSamples())
+	out := batteryAPIResponse{
+		Success: resp.GetSuccess() || len(samples) > 0,
+		Samples: samples,
+	}
+	if len(samples) == 0 && out.Error == "" {
+		out.Error = "battery status unavailable"
+	}
+	return out
+}
+
+func findBatterySample(samples []batterySampleJSON, clientID uint32) (batterySampleJSON, bool) {
+	for _, s := range samples {
+		if s.ClientID == clientID {
+			return s, true
+		}
+	}
+	return batterySampleJSON{}, false
+}
+
+// applyBatterySamplesToState merges UART/REST battery samples into dashboard views.
+func applyBatterySamplesToState(st *DashboardState, samples []batterySampleJSON) {
+	if st == nil || len(samples) == 0 {
+		return
+	}
+	if m, ok := findBatterySample(samples, 0); ok {
+		st.Master.Lipo1 = m.Lipo1
+		st.Master.Lipo2 = m.Lipo2
+		st.Master.BatteryAgeMs = m.AgeMs
+	}
+	for i := range st.Clients {
+		if s, ok := findBatterySample(samples, st.Clients[i].ID); ok {
+			st.Clients[i].Lipo1 = s.Lipo1
+			st.Clients[i].Lipo2 = s.Lipo2
+			st.Clients[i].BatteryAgeMs = s.AgeMs
+		}
+	}
+}

goTool/client_api.go

@@ -59,6 +59,86 @@ func (m *managedSerial) readAccelSnapshotPoll(clientID uint32) (*pb.AccelSnapsho
 	return decodeAccelSnapshotPayload(respPayload)
 }
 
+func decodeBatteryStatusPayload(payload []byte) (*pb.BatteryStatusResponse, error) {
+	if len(payload) < 2 {
+		return nil, fmt.Errorf("short battery response")
+	}
+	if payload[0] != byte(pb.MessageType_BATTERY_STATUS) {
+		return nil, fmt.Errorf("unexpected command id 0x%02x (want 0x%02x)",
+			payload[0], byte(pb.MessageType_BATTERY_STATUS))
+	}
+	var msg pb.UartMessage
+	if err := proto.Unmarshal(payload[1:], &msg); err != nil {
+		return nil, fmt.Errorf("decode: %w", err)
+	}
+	if msg.GetType() != pb.MessageType_BATTERY_STATUS {
+		return nil, fmt.Errorf("unexpected type %v", msg.GetType())
+	}
+	r := msg.GetBatteryStatusResponse()
+	if r == nil {
+		return nil, fmt.Errorf("missing battery_status_response")
+	}
+	return r, nil
+}
+
+func (m *managedSerial) BatteryStatus(req *pb.BatteryStatusRequest) (*pb.BatteryStatusResponse, error) {
+	var resp *pb.BatteryStatusResponse
+	err := m.withPort(func(sp *serialPort) error {
+		var e error
+		resp, e = sp.batteryStatus(req)
+		return e
+	})
+	return resp, err
+}
+
+func (m *managedSerial) BatteryStatusPoll(req *pb.BatteryStatusRequest) (*pb.BatteryStatusResponse, error) {
+	msg := &pb.UartMessage{
+		Type: pb.MessageType_BATTERY_STATUS,
+		Payload: &pb.UartMessage_BatteryStatusRequest{
+			BatteryStatusRequest: req,
+		},
+	}
+	body, err := proto.Marshal(msg)
+	if err != nil {
+		return nil, fmt.Errorf("encode: %w", err)
+	}
+	payload := append([]byte{byte(pb.MessageType_BATTERY_STATUS)}, body...)
+	respPayload, err := m.batteryStatusPayloadPoll(payload)
+	if err != nil {
+		return nil, err
+	}
+	return decodeBatteryStatusPayload(respPayload)
+}
+
+func (m *managedSerial) batteryStatusPayloadPoll(payload []byte) ([]byte, error) {
+	var resp []byte
+	err := m.withPortPoll(func(sp *serialPort) error {
+		var e error
+		resp, e = sp.exchangePayloadForBattery(payload, "BATTERY_STATUS")
+		return e
+	})
+	return resp, err
+}
+
+func (s *serialPort) batteryStatus(req *pb.BatteryStatusRequest) (*pb.BatteryStatusResponse, error) {
+	msg := &pb.UartMessage{
+		Type: pb.MessageType_BATTERY_STATUS,
+		Payload: &pb.UartMessage_BatteryStatusRequest{
+			BatteryStatusRequest: req,
+		},
+	}
+	body, err := proto.Marshal(msg)
+	if err != nil {
+		return nil, fmt.Errorf("encode: %w", err)
+	}
+	payload := append([]byte{byte(pb.MessageType_BATTERY_STATUS)}, body...)
+	respPayload, err := s.exchangePayloadForBattery(payload, "BATTERY_STATUS")
+	if err != nil {
+		return nil, err
+	}
+	return decodeBatteryStatusPayload(respPayload)
+}
+
 func (m *managedSerial) AccelStream(req *pb.AccelStreamRequest) (*pb.AccelStreamResponse, error) {
 	return m.accelStreamVia(m.withPort, req)
 }

goTool/cmd_serve.go

@@ -41,6 +41,7 @@ func runServe(portName string, baud int, args []string) error {
 	stop := make(chan struct{})
 	defer close(stop)
 	go runPoller(link, portName, hub, streamCtl, *interval, stop)
+	go runBatteryPoller(link, hub, 5*time.Second, stop)
 	go runAccelDashboardPoller(link, hub, *accelInterval, stop)
 
 	var apiSrv *http.Server

goTool/dashboard.go

@@ -19,6 +19,9 @@ type MasterView struct {
 	GitHash           string `json:"git_hash"`
 	RunningPartition  string `json:"running_partition,omitempty"`
 	Deadzone          uint32 `json:"deadzone,omitempty"`
+	Lipo1             lipoReadingJSON `json:"lipo1"`
+	Lipo2             lipoReadingJSON `json:"lipo2"`
+	BatteryAgeMs      uint32          `json:"battery_age_ms,omitempty"`
 	OK                bool            `json:"ok"`
 	Error             string `json:"error,omitempty"`
 }
@@ -38,6 +41,9 @@ type ClientView struct {
 	AccelZ          int32  `json:"accel_z"`
 	AccelAgeMs      uint32 `json:"accel_age_ms"`
 	AccelStream     bool            `json:"accel_stream"`
+	Lipo1           lipoReadingJSON `json:"lipo1"`
+	Lipo2           lipoReadingJSON `json:"lipo2"`
+	BatteryAgeMs    uint32          `json:"battery_age_ms,omitempty"`
 }
 
 type DashboardState struct {
@@ -62,8 +68,16 @@ func newWSHub() *wsHub {
 
 func (h *wsHub) setState(st DashboardState) {
 	h.mu.Lock()
-	prev := h.state.Clients
+	prev := h.state
-	st.Clients = preserveClientAccel(st.Clients, prev)
+	st.Clients = preserveClientAccel(st.Clients, prev.Clients)
+	st.Clients = preserveClientBattery(st.Clients, prev.Clients)
+	if !st.Master.Lipo1.Valid && !st.Master.Lipo2.Valid {
+		if prev.Master.Lipo1.Valid || prev.Master.Lipo2.Valid {
+			st.Master.Lipo1 = prev.Master.Lipo1
+			st.Master.Lipo2 = prev.Master.Lipo2
+			st.Master.BatteryAgeMs = prev.Master.BatteryAgeMs
+		}
+	}
 	h.state = st
 	conns := make([]*websocket.Conn, 0, len(h.clients))
 	for c := range h.clients {
@@ -156,6 +170,33 @@ func preserveClientAccel(newClients, oldClients []ClientView) []ClientView {
 	return out
 }
 
+func preserveClientBattery(newClients, oldClients []ClientView) []ClientView {
+	if len(oldClients) == 0 {
+		return newClients
+	}
+	oldByID := make(map[uint32]ClientView, len(oldClients))
+	for _, c := range oldClients {
+		oldByID[c.ID] = c
+	}
+	out := make([]ClientView, len(newClients))
+	for i, c := range newClients {
+		out[i] = c
+		if c.Lipo1.Valid || c.Lipo2.Valid {
+			continue
+		}
+		prev, ok := oldByID[c.ID]
+		if !ok {
+			continue
+		}
+		if prev.Lipo1.Valid || prev.Lipo2.Valid {
+			out[i].Lipo1 = prev.Lipo1
+			out[i].Lipo2 = prev.Lipo2
+			out[i].BatteryAgeMs = prev.BatteryAgeMs
+		}
+	}
+	return out
+}
+
 func anyClientAccelStream(clients []ClientView) bool {
 	for _, c := range clients {
 		if c.AccelStream {
@@ -294,6 +335,7 @@ func pollDashboard(link *managedSerial, portName string, last *DashboardState, s
 		}
 		st.Clients = append(st.Clients, cv)
 	}
+	applyBatteryToState(link, &st)
 	if anyClientAccelStream(st.Clients) {
 		for i := range st.Clients {
 			if !st.Clients[i].AccelStream {
@@ -319,6 +361,60 @@ func pollDashboard(link *managedSerial, portName string, last *DashboardState, s
 	return st
 }
 
+func applyBatteryToState(link *managedSerial, st *DashboardState) {
+	bat, err := link.BatteryStatusPoll(&pb.BatteryStatusRequest{AllClients: true})
+	if err != nil {
+		log.Printf("battery poll: %v", err)
+		return
+	}
+	applyBatterySamplesToState(st, batterySamplesFromPB(bat.GetSamples()))
+}
+
+func (h *wsHub) mergeBattery(samples []batterySampleJSON) {
+	if len(samples) == 0 {
+		return
+	}
+	h.mu.Lock()
+	st := h.state
+	applyBatterySamplesToState(&st, samples)
+	st.UpdatedAt = time.Now().Format(time.RFC3339)
+	h.state = st
+	conns := make([]*websocket.Conn, 0, len(h.clients))
+	for c := range h.clients {
+		conns = append(conns, c)
+	}
+	h.mu.Unlock()
+
+	data, err := json.Marshal(st)
+	if err != nil {
+		return
+	}
+	for _, c := range conns {
+		_ = c.WriteMessage(websocket.TextMessage, data)
+	}
+}
+
+func runBatteryPoller(link *managedSerial, hub *wsHub, interval time.Duration, stop <-chan struct{}) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-stop:
+			return
+		case <-ticker.C:
+			if hub.clientCount() == 0 {
+				continue
+			}
+			bat, err := link.BatteryStatusPoll(&pb.BatteryStatusRequest{AllClients: true})
+			if err != nil {
+				continue
+			}
+			hub.mergeBattery(batterySamplesFromPB(bat.GetSamples()))
+		}
+	}
+}
+
 func runAccelDashboardPoller(link *managedSerial, hub *wsHub, interval time.Duration, stop <-chan struct{}) {
 	ticker := time.NewTicker(interval)
 	defer ticker.Stop()

goTool/pb/uart_messages.pb.go

@@ -43,6 +43,7 @@ const (
 	MessageType_RESTART             MessageType = 23
 	MessageType_ACCEL_SNAPSHOT      MessageType = 24
 	MessageType_ACCEL_STREAM        MessageType = 25
+	MessageType_BATTERY_STATUS      MessageType = 26
 )
 
 // Enum value maps for MessageType.
@@ -67,6 +68,7 @@ var (
 		23: "RESTART",
 		24: "ACCEL_SNAPSHOT",
 		25: "ACCEL_STREAM",
+		26: "BATTERY_STATUS",
 	}
 	MessageType_value = map[string]int32{
 		"UNKNOWN":             0,
@@ -88,6 +90,7 @@ var (
 		"RESTART":             23,
 		"ACCEL_SNAPSHOT":      24,
 		"ACCEL_STREAM":        25,
+		"BATTERY_STATUS":      26,
 	}
 )
 
@@ -148,6 +151,8 @@ type UartMessage struct {
 	//	*UartMessage_AccelSnapshotResponse
 	//	*UartMessage_AccelStreamRequest
 	//	*UartMessage_AccelStreamResponse
+	//	*UartMessage_BatteryStatusRequest
+	//	*UartMessage_BatteryStatusResponse
 	Payload       isUartMessage_Payload `protobuf_oneof:"payload"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
@@ -422,6 +427,24 @@ func (x *UartMessage) GetAccelStreamResponse() *AccelStreamResponse {
 	return nil
 }
 
+func (x *UartMessage) GetBatteryStatusRequest() *BatteryStatusRequest {
+	if x != nil {
+		if x, ok := x.Payload.(*UartMessage_BatteryStatusRequest); ok {
+			return x.BatteryStatusRequest
+		}
+	}
+	return nil
+}
+
+func (x *UartMessage) GetBatteryStatusResponse() *BatteryStatusResponse {
+	if x != nil {
+		if x, ok := x.Payload.(*UartMessage_BatteryStatusResponse); ok {
+			return x.BatteryStatusResponse
+		}
+	}
+	return nil
+}
+
 type isUartMessage_Payload interface {
 	isUartMessage_Payload()
 }
@@ -526,6 +549,14 @@ type UartMessage_AccelStreamResponse struct {
 	AccelStreamResponse *AccelStreamResponse `protobuf:"bytes,26,opt,name=accel_stream_response,json=accelStreamResponse,proto3,oneof"`
 }
 
+type UartMessage_BatteryStatusRequest struct {
+	BatteryStatusRequest *BatteryStatusRequest `protobuf:"bytes,27,opt,name=battery_status_request,json=batteryStatusRequest,proto3,oneof"`
+}
+
+type UartMessage_BatteryStatusResponse struct {
+	BatteryStatusResponse *BatteryStatusResponse `protobuf:"bytes,28,opt,name=battery_status_response,json=batteryStatusResponse,proto3,oneof"`
+}
+
 func (*UartMessage_AckPayload) isUartMessage_Payload() {}
 
 func (*UartMessage_EchoPayload) isUartMessage_Payload() {}
@@ -576,6 +607,10 @@ func (*UartMessage_AccelStreamRequest) isUartMessage_Payload() {}
 
 func (*UartMessage_AccelStreamResponse) isUartMessage_Payload() {}
 
+func (*UartMessage_BatteryStatusRequest) isUartMessage_Payload() {}
+
+func (*UartMessage_BatteryStatusResponse) isUartMessage_Payload() {}
+
 type Ack struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	unknownFields protoimpl.UnknownFields
@@ -1251,6 +1286,235 @@ func (x *AccelStreamResponse) GetSlavesUpdated() uint32 {
 	return 0
 }
 
+// * Host → master: read LiPo ADC voltages (master local and/or slaves via ESP-NOW).
+type BatteryStatusRequest struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	// * 0 = master only; >0 = one slave; ignored when all_clients
+	ClientId uint32 `protobuf:"varint,1,opt,name=client_id,json=clientId,proto3" json:"client_id,omitempty"`
+	// * Master (client_id 0) plus every registered slave
+	AllClients    bool `protobuf:"varint,2,opt,name=all_clients,json=allClients,proto3" json:"all_clients,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *BatteryStatusRequest) Reset() {
+	*x = BatteryStatusRequest{}
+	mi := &file_uart_messages_proto_msgTypes[12]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *BatteryStatusRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*BatteryStatusRequest) ProtoMessage() {}
+
+func (x *BatteryStatusRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_uart_messages_proto_msgTypes[12]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use BatteryStatusRequest.ProtoReflect.Descriptor instead.
+func (*BatteryStatusRequest) Descriptor() ([]byte, []int) {
+	return file_uart_messages_proto_rawDescGZIP(), []int{12}
+}
+
+func (x *BatteryStatusRequest) GetClientId() uint32 {
+	if x != nil {
+		return x.ClientId
+	}
+	return 0
+}
+
+func (x *BatteryStatusRequest) GetAllClients() bool {
+	if x != nil {
+		return x.AllClients
+	}
+	return false
+}
+
+type LipoReading struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	Valid bool                   `protobuf:"varint,1,opt,name=valid,proto3" json:"valid,omitempty"`
+	// * Estimated pack voltage in millivolts from ADC
+	VoltageMv     uint32 `protobuf:"varint,2,opt,name=voltage_mv,json=voltageMv,proto3" json:"voltage_mv,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *LipoReading) Reset() {
+	*x = LipoReading{}
+	mi := &file_uart_messages_proto_msgTypes[13]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *LipoReading) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*LipoReading) ProtoMessage() {}
+
+func (x *LipoReading) ProtoReflect() protoreflect.Message {
+	mi := &file_uart_messages_proto_msgTypes[13]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use LipoReading.ProtoReflect.Descriptor instead.
+func (*LipoReading) Descriptor() ([]byte, []int) {
+	return file_uart_messages_proto_rawDescGZIP(), []int{13}
+}
+
+func (x *LipoReading) GetValid() bool {
+	if x != nil {
+		return x.Valid
+	}
+	return false
+}
+
+func (x *LipoReading) GetVoltageMv() uint32 {
+	if x != nil {
+		return x.VoltageMv
+	}
+	return 0
+}
+
+type BatterySample struct {
+	state    protoimpl.MessageState `protogen:"open.v1"`
+	ClientId uint32                 `protobuf:"varint,1,opt,name=client_id,json=clientId,proto3" json:"client_id,omitempty"`
+	Lipo1    *LipoReading           `protobuf:"bytes,2,opt,name=lipo1,proto3" json:"lipo1,omitempty"`
+	Lipo2    *LipoReading           `protobuf:"bytes,3,opt,name=lipo2,proto3" json:"lipo2,omitempty"`
+	// * Milliseconds since last ESP-NOW battery report from this pod.
+	AgeMs         uint32 `protobuf:"varint,4,opt,name=age_ms,json=ageMs,proto3" json:"age_ms,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *BatterySample) Reset() {
+	*x = BatterySample{}
+	mi := &file_uart_messages_proto_msgTypes[14]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *BatterySample) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*BatterySample) ProtoMessage() {}
+
+func (x *BatterySample) ProtoReflect() protoreflect.Message {
+	mi := &file_uart_messages_proto_msgTypes[14]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use BatterySample.ProtoReflect.Descriptor instead.
+func (*BatterySample) Descriptor() ([]byte, []int) {
+	return file_uart_messages_proto_rawDescGZIP(), []int{14}
+}
+
+func (x *BatterySample) GetClientId() uint32 {
+	if x != nil {
+		return x.ClientId
+	}
+	return 0
+}
+
+func (x *BatterySample) GetLipo1() *LipoReading {
+	if x != nil {
+		return x.Lipo1
+	}
+	return nil
+}
+
+func (x *BatterySample) GetLipo2() *LipoReading {
+	if x != nil {
+		return x.Lipo2
+	}
+	return nil
+}
+
+func (x *BatterySample) GetAgeMs() uint32 {
+	if x != nil {
+		return x.AgeMs
+	}
+	return 0
+}
+
+type BatteryStatusResponse struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Success       bool                   `protobuf:"varint,1,opt,name=success,proto3" json:"success,omitempty"`
+	Samples       []*BatterySample       `protobuf:"bytes,2,rep,name=samples,proto3" json:"samples,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *BatteryStatusResponse) Reset() {
+	*x = BatteryStatusResponse{}
+	mi := &file_uart_messages_proto_msgTypes[15]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *BatteryStatusResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*BatteryStatusResponse) ProtoMessage() {}
+
+func (x *BatteryStatusResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_uart_messages_proto_msgTypes[15]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use BatteryStatusResponse.ProtoReflect.Descriptor instead.
+func (*BatteryStatusResponse) Descriptor() ([]byte, []int) {
+	return file_uart_messages_proto_rawDescGZIP(), []int{15}
+}
+
+func (x *BatteryStatusResponse) GetSuccess() bool {
+	if x != nil {
+		return x.Success
+	}
+	return false
+}
+
+func (x *BatteryStatusResponse) GetSamples() []*BatterySample {
+	if x != nil {
+		return x.Samples
+	}
+	return nil
+}
+
 // Host → master: read cached accel samples from slaves (only while stream enabled).
 // client_id 0 = all registered slaves; otherwise one slave.
 type AccelSnapshotRequest struct {
@@ -1262,7 +1526,7 @@ type AccelSnapshotRequest struct {
 
 func (x *AccelSnapshotRequest) Reset() {
 	*x = AccelSnapshotRequest{}
-	mi := &file_uart_messages_proto_msgTypes[12]
+	mi := &file_uart_messages_proto_msgTypes[16]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1274,7 +1538,7 @@ func (x *AccelSnapshotRequest) String() string {
 func (*AccelSnapshotRequest) ProtoMessage() {}
 
 func (x *AccelSnapshotRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[12]
+	mi := &file_uart_messages_proto_msgTypes[16]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1287,7 +1551,7 @@ func (x *AccelSnapshotRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AccelSnapshotRequest.ProtoReflect.Descriptor instead.
 func (*AccelSnapshotRequest) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{12}
+	return file_uart_messages_proto_rawDescGZIP(), []int{16}
 }
 
 func (x *AccelSnapshotRequest) GetClientId() uint32 {
@@ -1312,7 +1576,7 @@ type AccelSample struct {
 
 func (x *AccelSample) Reset() {
 	*x = AccelSample{}
-	mi := &file_uart_messages_proto_msgTypes[13]
+	mi := &file_uart_messages_proto_msgTypes[17]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1324,7 +1588,7 @@ func (x *AccelSample) String() string {
 func (*AccelSample) ProtoMessage() {}
 
 func (x *AccelSample) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[13]
+	mi := &file_uart_messages_proto_msgTypes[17]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1337,7 +1601,7 @@ func (x *AccelSample) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AccelSample.ProtoReflect.Descriptor instead.
 func (*AccelSample) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{13}
+	return file_uart_messages_proto_rawDescGZIP(), []int{17}
 }
 
 func (x *AccelSample) GetClientId() uint32 {
@@ -1391,7 +1655,7 @@ type AccelSnapshotResponse struct {
 
 func (x *AccelSnapshotResponse) Reset() {
 	*x = AccelSnapshotResponse{}
-	mi := &file_uart_messages_proto_msgTypes[14]
+	mi := &file_uart_messages_proto_msgTypes[18]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1403,7 +1667,7 @@ func (x *AccelSnapshotResponse) String() string {
 func (*AccelSnapshotResponse) ProtoMessage() {}
 
 func (x *AccelSnapshotResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[14]
+	mi := &file_uart_messages_proto_msgTypes[18]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1416,7 +1680,7 @@ func (x *AccelSnapshotResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AccelSnapshotResponse.ProtoReflect.Descriptor instead.
 func (*AccelSnapshotResponse) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{14}
+	return file_uart_messages_proto_rawDescGZIP(), []int{18}
 }
 
 func (x *AccelSnapshotResponse) GetSamples() []*AccelSample {
@@ -1436,7 +1700,7 @@ type EspNowUnicastTestRequest struct {
 
 func (x *EspNowUnicastTestRequest) Reset() {
 	*x = EspNowUnicastTestRequest{}
-	mi := &file_uart_messages_proto_msgTypes[15]
+	mi := &file_uart_messages_proto_msgTypes[19]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1448,7 +1712,7 @@ func (x *EspNowUnicastTestRequest) String() string {
 func (*EspNowUnicastTestRequest) ProtoMessage() {}
 
 func (x *EspNowUnicastTestRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[15]
+	mi := &file_uart_messages_proto_msgTypes[19]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1461,7 +1725,7 @@ func (x *EspNowUnicastTestRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use EspNowUnicastTestRequest.ProtoReflect.Descriptor instead.
 func (*EspNowUnicastTestRequest) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{15}
+	return file_uart_messages_proto_rawDescGZIP(), []int{19}
 }
 
 func (x *EspNowUnicastTestRequest) GetClientId() uint32 {
@@ -1488,7 +1752,7 @@ type EspNowUnicastTestResponse struct {
 
 func (x *EspNowUnicastTestResponse) Reset() {
 	*x = EspNowUnicastTestResponse{}
-	mi := &file_uart_messages_proto_msgTypes[16]
+	mi := &file_uart_messages_proto_msgTypes[20]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1500,7 +1764,7 @@ func (x *EspNowUnicastTestResponse) String() string {
 func (*EspNowUnicastTestResponse) ProtoMessage() {}
 
 func (x *EspNowUnicastTestResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[16]
+	mi := &file_uart_messages_proto_msgTypes[20]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1513,7 +1777,7 @@ func (x *EspNowUnicastTestResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use EspNowUnicastTestResponse.ProtoReflect.Descriptor instead.
 func (*EspNowUnicastTestResponse) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{16}
+	return file_uart_messages_proto_rawDescGZIP(), []int{20}
 }
 
 func (x *EspNowUnicastTestResponse) GetSuccess() bool {
@@ -1560,7 +1824,7 @@ type LedRingProgressRequest struct {
 
 func (x *LedRingProgressRequest) Reset() {
 	*x = LedRingProgressRequest{}
-	mi := &file_uart_messages_proto_msgTypes[17]
+	mi := &file_uart_messages_proto_msgTypes[21]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1572,7 +1836,7 @@ func (x *LedRingProgressRequest) String() string {
 func (*LedRingProgressRequest) ProtoMessage() {}
 
 func (x *LedRingProgressRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[17]
+	mi := &file_uart_messages_proto_msgTypes[21]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1585,7 +1849,7 @@ func (x *LedRingProgressRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use LedRingProgressRequest.ProtoReflect.Descriptor instead.
 func (*LedRingProgressRequest) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{17}
+	return file_uart_messages_proto_rawDescGZIP(), []int{21}
 }
 
 func (x *LedRingProgressRequest) GetMode() uint32 {
@@ -1686,7 +1950,7 @@ type LedRingProgressResponse struct {
 
 func (x *LedRingProgressResponse) Reset() {
 	*x = LedRingProgressResponse{}
-	mi := &file_uart_messages_proto_msgTypes[18]
+	mi := &file_uart_messages_proto_msgTypes[22]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1698,7 +1962,7 @@ func (x *LedRingProgressResponse) String() string {
 func (*LedRingProgressResponse) ProtoMessage() {}
 
 func (x *LedRingProgressResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[18]
+	mi := &file_uart_messages_proto_msgTypes[22]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1711,7 +1975,7 @@ func (x *LedRingProgressResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use LedRingProgressResponse.ProtoReflect.Descriptor instead.
 func (*LedRingProgressResponse) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{18}
+	return file_uart_messages_proto_rawDescGZIP(), []int{22}
 }
 
 func (x *LedRingProgressResponse) GetSuccess() bool {
@@ -1766,7 +2030,7 @@ type EspNowFindMeRequest struct {
 
 func (x *EspNowFindMeRequest) Reset() {
 	*x = EspNowFindMeRequest{}
-	mi := &file_uart_messages_proto_msgTypes[19]
+	mi := &file_uart_messages_proto_msgTypes[23]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1778,7 +2042,7 @@ func (x *EspNowFindMeRequest) String() string {
 func (*EspNowFindMeRequest) ProtoMessage() {}
 
 func (x *EspNowFindMeRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[19]
+	mi := &file_uart_messages_proto_msgTypes[23]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1791,7 +2055,7 @@ func (x *EspNowFindMeRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use EspNowFindMeRequest.ProtoReflect.Descriptor instead.
 func (*EspNowFindMeRequest) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{19}
+	return file_uart_messages_proto_rawDescGZIP(), []int{23}
 }
 
 func (x *EspNowFindMeRequest) GetClientId() uint32 {
@@ -1811,7 +2075,7 @@ type EspNowFindMeResponse struct {
 
 func (x *EspNowFindMeResponse) Reset() {
 	*x = EspNowFindMeResponse{}
-	mi := &file_uart_messages_proto_msgTypes[20]
+	mi := &file_uart_messages_proto_msgTypes[24]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1823,7 +2087,7 @@ func (x *EspNowFindMeResponse) String() string {
 func (*EspNowFindMeResponse) ProtoMessage() {}
 
 func (x *EspNowFindMeResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[20]
+	mi := &file_uart_messages_proto_msgTypes[24]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1836,7 +2100,7 @@ func (x *EspNowFindMeResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use EspNowFindMeResponse.ProtoReflect.Descriptor instead.
 func (*EspNowFindMeResponse) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{20}
+	return file_uart_messages_proto_rawDescGZIP(), []int{24}
 }
 
 func (x *EspNowFindMeResponse) GetSuccess() bool {
@@ -1863,7 +2127,7 @@ type RestartRequest struct {
 
 func (x *RestartRequest) Reset() {
 	*x = RestartRequest{}
-	mi := &file_uart_messages_proto_msgTypes[21]
+	mi := &file_uart_messages_proto_msgTypes[25]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1875,7 +2139,7 @@ func (x *RestartRequest) String() string {
 func (*RestartRequest) ProtoMessage() {}
 
 func (x *RestartRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[21]
+	mi := &file_uart_messages_proto_msgTypes[25]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1888,7 +2152,7 @@ func (x *RestartRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use RestartRequest.ProtoReflect.Descriptor instead.
 func (*RestartRequest) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{21}
+	return file_uart_messages_proto_rawDescGZIP(), []int{25}
 }
 
 func (x *RestartRequest) GetClientId() uint32 {
@@ -1908,7 +2172,7 @@ type RestartResponse struct {
 
 func (x *RestartResponse) Reset() {
 	*x = RestartResponse{}
-	mi := &file_uart_messages_proto_msgTypes[22]
+	mi := &file_uart_messages_proto_msgTypes[26]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1920,7 +2184,7 @@ func (x *RestartResponse) String() string {
 func (*RestartResponse) ProtoMessage() {}
 
 func (x *RestartResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[22]
+	mi := &file_uart_messages_proto_msgTypes[26]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1933,7 +2197,7 @@ func (x *RestartResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use RestartResponse.ProtoReflect.Descriptor instead.
 func (*RestartResponse) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{22}
+	return file_uart_messages_proto_rawDescGZIP(), []int{26}
 }
 
 func (x *RestartResponse) GetSuccess() bool {
@@ -1960,7 +2224,7 @@ type OtaStartPayload struct {
 
 func (x *OtaStartPayload) Reset() {
 	*x = OtaStartPayload{}
-	mi := &file_uart_messages_proto_msgTypes[23]
+	mi := &file_uart_messages_proto_msgTypes[27]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1972,7 +2236,7 @@ func (x *OtaStartPayload) String() string {
 func (*OtaStartPayload) ProtoMessage() {}
 
 func (x *OtaStartPayload) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[23]
+	mi := &file_uart_messages_proto_msgTypes[27]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1985,7 +2249,7 @@ func (x *OtaStartPayload) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaStartPayload.ProtoReflect.Descriptor instead.
 func (*OtaStartPayload) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{23}
+	return file_uart_messages_proto_rawDescGZIP(), []int{27}
 }
 
 func (x *OtaStartPayload) GetTotalSize() uint32 {
@@ -2006,7 +2270,7 @@ type OtaPayload struct {
 
 func (x *OtaPayload) Reset() {
 	*x = OtaPayload{}
-	mi := &file_uart_messages_proto_msgTypes[24]
+	mi := &file_uart_messages_proto_msgTypes[28]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -2018,7 +2282,7 @@ func (x *OtaPayload) String() string {
 func (*OtaPayload) ProtoMessage() {}
 
 func (x *OtaPayload) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[24]
+	mi := &file_uart_messages_proto_msgTypes[28]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -2031,7 +2295,7 @@ func (x *OtaPayload) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaPayload.ProtoReflect.Descriptor instead.
 func (*OtaPayload) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{24}
+	return file_uart_messages_proto_rawDescGZIP(), []int{28}
 }
 
 func (x *OtaPayload) GetSeq() uint32 {
@@ -2057,7 +2321,7 @@ type OtaEndPayload struct {
 
 func (x *OtaEndPayload) Reset() {
 	*x = OtaEndPayload{}
-	mi := &file_uart_messages_proto_msgTypes[25]
+	mi := &file_uart_messages_proto_msgTypes[29]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -2069,7 +2333,7 @@ func (x *OtaEndPayload) String() string {
 func (*OtaEndPayload) ProtoMessage() {}
 
 func (x *OtaEndPayload) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[25]
+	mi := &file_uart_messages_proto_msgTypes[29]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -2082,7 +2346,7 @@ func (x *OtaEndPayload) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaEndPayload.ProtoReflect.Descriptor instead.
 func (*OtaEndPayload) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{25}
+	return file_uart_messages_proto_rawDescGZIP(), []int{29}
 }
 
 // Device → host status (also used as ACK after each 4 KiB written).
@@ -2099,7 +2363,7 @@ type OtaStatusPayload struct {
 
 func (x *OtaStatusPayload) Reset() {
 	*x = OtaStatusPayload{}
-	mi := &file_uart_messages_proto_msgTypes[26]
+	mi := &file_uart_messages_proto_msgTypes[30]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -2111,7 +2375,7 @@ func (x *OtaStatusPayload) String() string {
 func (*OtaStatusPayload) ProtoMessage() {}
 
 func (x *OtaStatusPayload) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[26]
+	mi := &file_uart_messages_proto_msgTypes[30]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -2124,7 +2388,7 @@ func (x *OtaStatusPayload) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaStatusPayload.ProtoReflect.Descriptor instead.
 func (*OtaStatusPayload) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{26}
+	return file_uart_messages_proto_rawDescGZIP(), []int{30}
 }
 
 func (x *OtaStatusPayload) GetStatus() uint32 {
@@ -2165,7 +2429,7 @@ type OtaSlaveProgressRequest struct {
 
 func (x *OtaSlaveProgressRequest) Reset() {
 	*x = OtaSlaveProgressRequest{}
-	mi := &file_uart_messages_proto_msgTypes[27]
+	mi := &file_uart_messages_proto_msgTypes[31]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -2177,7 +2441,7 @@ func (x *OtaSlaveProgressRequest) String() string {
 func (*OtaSlaveProgressRequest) ProtoMessage() {}
 
 func (x *OtaSlaveProgressRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[27]
+	mi := &file_uart_messages_proto_msgTypes[31]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -2190,7 +2454,7 @@ func (x *OtaSlaveProgressRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaSlaveProgressRequest.ProtoReflect.Descriptor instead.
 func (*OtaSlaveProgressRequest) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{27}
+	return file_uart_messages_proto_rawDescGZIP(), []int{31}
 }
 
 func (x *OtaSlaveProgressRequest) GetClientId() uint32 {
@@ -2214,7 +2478,7 @@ type OtaSlaveProgressEntry struct {
 
 func (x *OtaSlaveProgressEntry) Reset() {
 	*x = OtaSlaveProgressEntry{}
-	mi := &file_uart_messages_proto_msgTypes[28]
+	mi := &file_uart_messages_proto_msgTypes[32]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -2226,7 +2490,7 @@ func (x *OtaSlaveProgressEntry) String() string {
 func (*OtaSlaveProgressEntry) ProtoMessage() {}
 
 func (x *OtaSlaveProgressEntry) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[28]
+	mi := &file_uart_messages_proto_msgTypes[32]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -2239,7 +2503,7 @@ func (x *OtaSlaveProgressEntry) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaSlaveProgressEntry.ProtoReflect.Descriptor instead.
 func (*OtaSlaveProgressEntry) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{28}
+	return file_uart_messages_proto_rawDescGZIP(), []int{32}
 }
 
 func (x *OtaSlaveProgressEntry) GetClientId() uint32 {
@@ -2290,7 +2554,7 @@ type OtaSlaveProgressResponse struct {
 
 func (x *OtaSlaveProgressResponse) Reset() {
 	*x = OtaSlaveProgressResponse{}
-	mi := &file_uart_messages_proto_msgTypes[29]
+	mi := &file_uart_messages_proto_msgTypes[33]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -2302,7 +2566,7 @@ func (x *OtaSlaveProgressResponse) String() string {
 func (*OtaSlaveProgressResponse) ProtoMessage() {}
 
 func (x *OtaSlaveProgressResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_uart_messages_proto_msgTypes[29]
+	mi := &file_uart_messages_proto_msgTypes[33]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -2315,7 +2579,7 @@ func (x *OtaSlaveProgressResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use OtaSlaveProgressResponse.ProtoReflect.Descriptor instead.
 func (*OtaSlaveProgressResponse) Descriptor() ([]byte, []int) {
-	return file_uart_messages_proto_rawDescGZIP(), []int{29}
+	return file_uart_messages_proto_rawDescGZIP(), []int{33}
 }
 
 func (x *OtaSlaveProgressResponse) GetActive() bool {
@@ -2357,7 +2621,7 @@ var File_uart_messages_proto protoreflect.FileDescriptor
 
 const file_uart_messages_proto_rawDesc = "" +
 	"\n" +
-	"\x13uart_messages.proto\x12\x04alox\x1a\fnanopb.proto\"\xba\x0f\n" +
+	"\x13uart_messages.proto\x12\x04alox\x1a\fnanopb.proto\"\xe5\x10\n" +
 	"\vUartMessage\x12%\n" +
 	"\x04type\x18\x01 \x01(\x0e2\x11.alox.MessageTypeR\x04type\x12,\n" +
 	"\vack_payload\x18\x02 \x01(\v2\t.alox.AckH\x00R\n" +
@@ -2388,7 +2652,9 @@ const file_uart_messages_proto_rawDesc = "" +
 	"\x16accel_snapshot_request\x18\x17 \x01(\v2\x1a.alox.AccelSnapshotRequestH\x00R\x14accelSnapshotRequest\x12U\n" +
 	"\x17accel_snapshot_response\x18\x18 \x01(\v2\x1b.alox.AccelSnapshotResponseH\x00R\x15accelSnapshotResponse\x12L\n" +
 	"\x14accel_stream_request\x18\x19 \x01(\v2\x18.alox.AccelStreamRequestH\x00R\x12accelStreamRequest\x12O\n" +
-	"\x15accel_stream_response\x18\x1a \x01(\v2\x19.alox.AccelStreamResponseH\x00R\x13accelStreamResponseB\t\n" +
+	"\x15accel_stream_response\x18\x1a \x01(\v2\x19.alox.AccelStreamResponseH\x00R\x13accelStreamResponse\x12R\n" +
+	"\x16battery_status_request\x18\x1b \x01(\v2\x1a.alox.BatteryStatusRequestH\x00R\x14batteryStatusRequest\x12U\n" +
+	"\x17battery_status_response\x18\x1c \x01(\v2\x1b.alox.BatteryStatusResponseH\x00R\x15batteryStatusResponseB\t\n" +
 	"\apayload\"\x05\n" +
 	"\x03Ack\"!\n" +
 	"\vEchoPayload\x12\x12\n" +
@@ -2437,7 +2703,23 @@ const file_uart_messages_proto_rawDesc = "" +
 	"\aenabled\x18\x01 \x01(\bR\aenabled\x12\x1b\n" +
 	"\tclient_id\x18\x02 \x01(\rR\bclientId\x12\x18\n" +
 	"\asuccess\x18\x03 \x01(\bR\asuccess\x12%\n" +
-	"\x0eslaves_updated\x18\x04 \x01(\rR\rslavesUpdated\"3\n" +
+	"\x0eslaves_updated\x18\x04 \x01(\rR\rslavesUpdated\"T\n" +
+	"\x14BatteryStatusRequest\x12\x1b\n" +
+	"\tclient_id\x18\x01 \x01(\rR\bclientId\x12\x1f\n" +
+	"\vall_clients\x18\x02 \x01(\bR\n" +
+	"allClients\"B\n" +
+	"\vLipoReading\x12\x14\n" +
+	"\x05valid\x18\x01 \x01(\bR\x05valid\x12\x1d\n" +
+	"\n" +
+	"voltage_mv\x18\x02 \x01(\rR\tvoltageMv\"\x95\x01\n" +
+	"\rBatterySample\x12\x1b\n" +
+	"\tclient_id\x18\x01 \x01(\rR\bclientId\x12'\n" +
+	"\x05lipo1\x18\x02 \x01(\v2\x11.alox.LipoReadingR\x05lipo1\x12'\n" +
+	"\x05lipo2\x18\x03 \x01(\v2\x11.alox.LipoReadingR\x05lipo2\x12\x15\n" +
+	"\x06age_ms\x18\x04 \x01(\rR\x05ageMs\"g\n" +
+	"\x15BatteryStatusResponse\x12\x18\n" +
+	"\asuccess\x18\x01 \x01(\bR\asuccess\x124\n" +
+	"\asamples\x18\x02 \x03(\v2\x13.alox.BatterySampleB\x05\x92?\x02\x10\x11R\asamples\"3\n" +
 	"\x14AccelSnapshotRequest\x12\x1b\n" +
 	"\tclient_id\x18\x01 \x01(\rR\bclientId\"\x81\x01\n" +
 	"\vAccelSample\x12\x1b\n" +
@@ -2519,7 +2801,7 @@ const file_uart_messages_proto_rawDesc = "" +
 	"\x0faggregate_bytes\x18\x03 \x01(\rR\x0eaggregateBytes\x12\x1f\n" +
 	"\vslave_count\x18\x04 \x01(\rR\n" +
 	"slaveCount\x12:\n" +
-	"\x06slaves\x18\x05 \x03(\v2\x1b.alox.OtaSlaveProgressEntryB\x05\x92?\x02\x10\x10R\x06slaves*\xc3\x02\n" +
+	"\x06slaves\x18\x05 \x03(\v2\x1b.alox.OtaSlaveProgressEntryB\x05\x92?\x02\x10\x10R\x06slaves*\xd7\x02\n" +
 	"\vMessageType\x12\v\n" +
 	"\aUNKNOWN\x10\x00\x12\a\n" +
 	"\x03ACK\x10\x01\x12\b\n" +
@@ -2540,7 +2822,8 @@ const file_uart_messages_proto_rawDesc = "" +
 	"\aFIND_ME\x10\x16\x12\v\n" +
 	"\aRESTART\x10\x17\x12\x12\n" +
 	"\x0eACCEL_SNAPSHOT\x10\x18\x12\x10\n" +
-	"\fACCEL_STREAM\x10\x19b\x06proto3"
+	"\fACCEL_STREAM\x10\x19\x12\x12\n" +
+	"\x0eBATTERY_STATUS\x10\x1ab\x06proto3"
 
 var (
 	file_uart_messages_proto_rawDescOnce sync.Once
@@ -2555,7 +2838,7 @@ func file_uart_messages_proto_rawDescGZIP() []byte {
 }
 
 var file_uart_messages_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
-var file_uart_messages_proto_msgTypes = make([]protoimpl.MessageInfo, 30)
+var file_uart_messages_proto_msgTypes = make([]protoimpl.MessageInfo, 34)
 var file_uart_messages_proto_goTypes = []any{
 	(MessageType)(0),                  // 0: alox.MessageType
 	(*UartMessage)(nil),               // 1: alox.UartMessage
@@ -2570,24 +2853,28 @@ var file_uart_messages_proto_goTypes = []any{
 	(*AccelDeadzoneResponse)(nil),     // 10: alox.AccelDeadzoneResponse
 	(*AccelStreamRequest)(nil),        // 11: alox.AccelStreamRequest
 	(*AccelStreamResponse)(nil),       // 12: alox.AccelStreamResponse
-	(*AccelSnapshotRequest)(nil),      // 13: alox.AccelSnapshotRequest
+	(*BatteryStatusRequest)(nil),      // 13: alox.BatteryStatusRequest
-	(*AccelSample)(nil),               // 14: alox.AccelSample
+	(*LipoReading)(nil),               // 14: alox.LipoReading
-	(*AccelSnapshotResponse)(nil),     // 15: alox.AccelSnapshotResponse
+	(*BatterySample)(nil),             // 15: alox.BatterySample
-	(*EspNowUnicastTestRequest)(nil),  // 16: alox.EspNowUnicastTestRequest
+	(*BatteryStatusResponse)(nil),     // 16: alox.BatteryStatusResponse
-	(*EspNowUnicastTestResponse)(nil), // 17: alox.EspNowUnicastTestResponse
+	(*AccelSnapshotRequest)(nil),      // 17: alox.AccelSnapshotRequest
-	(*LedRingProgressRequest)(nil),    // 18: alox.LedRingProgressRequest
+	(*AccelSample)(nil),               // 18: alox.AccelSample
-	(*LedRingProgressResponse)(nil),   // 19: alox.LedRingProgressResponse
+	(*AccelSnapshotResponse)(nil),     // 19: alox.AccelSnapshotResponse
-	(*EspNowFindMeRequest)(nil),       // 20: alox.EspNowFindMeRequest
+	(*EspNowUnicastTestRequest)(nil),  // 20: alox.EspNowUnicastTestRequest
-	(*EspNowFindMeResponse)(nil),      // 21: alox.EspNowFindMeResponse
+	(*EspNowUnicastTestResponse)(nil), // 21: alox.EspNowUnicastTestResponse
-	(*RestartRequest)(nil),            // 22: alox.RestartRequest
+	(*LedRingProgressRequest)(nil),    // 22: alox.LedRingProgressRequest
-	(*RestartResponse)(nil),           // 23: alox.RestartResponse
+	(*LedRingProgressResponse)(nil),   // 23: alox.LedRingProgressResponse
-	(*OtaStartPayload)(nil),           // 24: alox.OtaStartPayload
+	(*EspNowFindMeRequest)(nil),       // 24: alox.EspNowFindMeRequest
-	(*OtaPayload)(nil),                // 25: alox.OtaPayload
+	(*EspNowFindMeResponse)(nil),      // 25: alox.EspNowFindMeResponse
-	(*OtaEndPayload)(nil),             // 26: alox.OtaEndPayload
+	(*RestartRequest)(nil),            // 26: alox.RestartRequest
-	(*OtaStatusPayload)(nil),          // 27: alox.OtaStatusPayload
+	(*RestartResponse)(nil),           // 27: alox.RestartResponse
-	(*OtaSlaveProgressRequest)(nil),   // 28: alox.OtaSlaveProgressRequest
+	(*OtaStartPayload)(nil),           // 28: alox.OtaStartPayload
-	(*OtaSlaveProgressEntry)(nil),     // 29: alox.OtaSlaveProgressEntry
+	(*OtaPayload)(nil),                // 29: alox.OtaPayload
-	(*OtaSlaveProgressResponse)(nil),  // 30: alox.OtaSlaveProgressResponse
+	(*OtaEndPayload)(nil),             // 30: alox.OtaEndPayload
+	(*OtaStatusPayload)(nil),          // 31: alox.OtaStatusPayload
+	(*OtaSlaveProgressRequest)(nil),   // 32: alox.OtaSlaveProgressRequest
+	(*OtaSlaveProgressEntry)(nil),     // 33: alox.OtaSlaveProgressEntry
+	(*OtaSlaveProgressResponse)(nil),  // 34: alox.OtaSlaveProgressResponse
 }
 var file_uart_messages_proto_depIdxs = []int32{
 	0,  // 0: alox.UartMessage.type:type_name -> alox.MessageType
@@ -2596,35 +2883,40 @@ var file_uart_messages_proto_depIdxs = []int32{
 	4,  // 3: alox.UartMessage.version_response:type_name -> alox.VersionResponse
 	6,  // 4: alox.UartMessage.client_info_response:type_name -> alox.ClientInfoResponse
 	8,  // 5: alox.UartMessage.client_input_response:type_name -> alox.ClientInputResponse
-	24, // 6: alox.UartMessage.ota_start:type_name -> alox.OtaStartPayload
+	28, // 6: alox.UartMessage.ota_start:type_name -> alox.OtaStartPayload
-	25, // 7: alox.UartMessage.ota_payload:type_name -> alox.OtaPayload
+	29, // 7: alox.UartMessage.ota_payload:type_name -> alox.OtaPayload
-	26, // 8: alox.UartMessage.ota_end:type_name -> alox.OtaEndPayload
+	30, // 8: alox.UartMessage.ota_end:type_name -> alox.OtaEndPayload
-	27, // 9: alox.UartMessage.ota_status:type_name -> alox.OtaStatusPayload
+	31, // 9: alox.UartMessage.ota_status:type_name -> alox.OtaStatusPayload
 	9,  // 10: alox.UartMessage.accel_deadzone_request:type_name -> alox.AccelDeadzoneRequest
 	10, // 11: alox.UartMessage.accel_deadzone_response:type_name -> alox.AccelDeadzoneResponse
-	16, // 12: alox.UartMessage.espnow_unicast_test_request:type_name -> alox.EspNowUnicastTestRequest
+	20, // 12: alox.UartMessage.espnow_unicast_test_request:type_name -> alox.EspNowUnicastTestRequest
-	17, // 13: alox.UartMessage.espnow_unicast_test_response:type_name -> alox.EspNowUnicastTestResponse
+	21, // 13: alox.UartMessage.espnow_unicast_test_response:type_name -> alox.EspNowUnicastTestResponse
-	28, // 14: alox.UartMessage.ota_slave_progress_request:type_name -> alox.OtaSlaveProgressRequest
+	32, // 14: alox.UartMessage.ota_slave_progress_request:type_name -> alox.OtaSlaveProgressRequest
-	30, // 15: alox.UartMessage.ota_slave_progress_response:type_name -> alox.OtaSlaveProgressResponse
+	34, // 15: alox.UartMessage.ota_slave_progress_response:type_name -> alox.OtaSlaveProgressResponse
-	18, // 16: alox.UartMessage.led_ring_progress_request:type_name -> alox.LedRingProgressRequest
+	22, // 16: alox.UartMessage.led_ring_progress_request:type_name -> alox.LedRingProgressRequest
-	19, // 17: alox.UartMessage.led_ring_progress_response:type_name -> alox.LedRingProgressResponse
+	23, // 17: alox.UartMessage.led_ring_progress_response:type_name -> alox.LedRingProgressResponse
-	20, // 18: alox.UartMessage.espnow_find_me_request:type_name -> alox.EspNowFindMeRequest
+	24, // 18: alox.UartMessage.espnow_find_me_request:type_name -> alox.EspNowFindMeRequest
-	21, // 19: alox.UartMessage.espnow_find_me_response:type_name -> alox.EspNowFindMeResponse
+	25, // 19: alox.UartMessage.espnow_find_me_response:type_name -> alox.EspNowFindMeResponse
-	22, // 20: alox.UartMessage.restart_request:type_name -> alox.RestartRequest
+	26, // 20: alox.UartMessage.restart_request:type_name -> alox.RestartRequest
-	23, // 21: alox.UartMessage.restart_response:type_name -> alox.RestartResponse
+	27, // 21: alox.UartMessage.restart_response:type_name -> alox.RestartResponse
-	13, // 22: alox.UartMessage.accel_snapshot_request:type_name -> alox.AccelSnapshotRequest
+	17, // 22: alox.UartMessage.accel_snapshot_request:type_name -> alox.AccelSnapshotRequest
-	15, // 23: alox.UartMessage.accel_snapshot_response:type_name -> alox.AccelSnapshotResponse
+	19, // 23: alox.UartMessage.accel_snapshot_response:type_name -> alox.AccelSnapshotResponse
 	11, // 24: alox.UartMessage.accel_stream_request:type_name -> alox.AccelStreamRequest
 	12, // 25: alox.UartMessage.accel_stream_response:type_name -> alox.AccelStreamResponse
-	5,  // 26: alox.ClientInfoResponse.clients:type_name -> alox.ClientInfo
+	13, // 26: alox.UartMessage.battery_status_request:type_name -> alox.BatteryStatusRequest
-	7,  // 27: alox.ClientInputResponse.clients:type_name -> alox.ClientInput
+	16, // 27: alox.UartMessage.battery_status_response:type_name -> alox.BatteryStatusResponse
-	14, // 28: alox.AccelSnapshotResponse.samples:type_name -> alox.AccelSample
+	5,  // 28: alox.ClientInfoResponse.clients:type_name -> alox.ClientInfo
-	29, // 29: alox.OtaSlaveProgressResponse.slaves:type_name -> alox.OtaSlaveProgressEntry
+	7,  // 29: alox.ClientInputResponse.clients:type_name -> alox.ClientInput
-	30, // [30:30] is the sub-list for method output_type
+	14, // 30: alox.BatterySample.lipo1:type_name -> alox.LipoReading
-	30, // [30:30] is the sub-list for method input_type
+	14, // 31: alox.BatterySample.lipo2:type_name -> alox.LipoReading
-	30, // [30:30] is the sub-list for extension type_name
+	15, // 32: alox.BatteryStatusResponse.samples:type_name -> alox.BatterySample
-	30, // [30:30] is the sub-list for extension extendee
+	18, // 33: alox.AccelSnapshotResponse.samples:type_name -> alox.AccelSample
-	0,  // [0:30] is the sub-list for field type_name
+	33, // 34: alox.OtaSlaveProgressResponse.slaves:type_name -> alox.OtaSlaveProgressEntry
+	35, // [35:35] is the sub-list for method output_type
+	35, // [35:35] is the sub-list for method input_type
+	35, // [35:35] is the sub-list for extension type_name
+	35, // [35:35] is the sub-list for extension extendee
+	0,  // [0:35] is the sub-list for field type_name
 }
 
 func init() { file_uart_messages_proto_init() }
@@ -2658,6 +2950,8 @@ func file_uart_messages_proto_init() {
 		(*UartMessage_AccelSnapshotResponse)(nil),
 		(*UartMessage_AccelStreamRequest)(nil),
 		(*UartMessage_AccelStreamResponse)(nil),
+		(*UartMessage_BatteryStatusRequest)(nil),
+		(*UartMessage_BatteryStatusResponse)(nil),
 	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
@@ -2665,7 +2959,7 @@ func file_uart_messages_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_uart_messages_proto_rawDesc), len(file_uart_messages_proto_rawDesc)),
 			NumEnums:      1,
-			NumMessages:   30,
+			NumMessages:   34,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

goTool/serial_link.go

@@ -119,7 +119,7 @@ func (m *managedSerial) exchangePayloadVia(
 	var resp []byte
 	err := portFn(func(sp *serialPort) error {
 		var e error
-		resp, e = sp.exchangePayloadLocked(payload, cmdName)
+		resp, e = sp.exchangePayloadLocked(payload, cmdName, readTimeout)
 		return e
 	})
 	return resp, err

goTool/serialport.go

@@ -12,6 +12,9 @@ import (
 
 const readTimeout = 3 * time.Second
 
+// batteryReadTimeout: master may query each slave over ESP-NOW (~400 ms each).
+const batteryReadTimeout = 12 * time.Second
+
 type serialPort struct {
 	port  serial.Port
 	mu    sync.Mutex
@@ -44,10 +47,16 @@ func (s *serialPort) Close() error {
 func (s *serialPort) exchangePayload(payload []byte, cmdName string) ([]byte, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	return s.exchangePayloadLocked(payload, cmdName)
+	return s.exchangePayloadLocked(payload, cmdName, readTimeout)
 }
 
-func (s *serialPort) exchangePayloadLocked(payload []byte, cmdName string) ([]byte, error) {
+func (s *serialPort) exchangePayloadForBattery(payload []byte, cmdName string) ([]byte, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.exchangePayloadLocked(payload, cmdName, batteryReadTimeout)
+}
+
+func (s *serialPort) exchangePayloadLocked(payload []byte, cmdName string, timeout time.Duration) ([]byte, error) {
 	if len(payload) == 0 {
 		return nil, fmt.Errorf("empty payload")
 	}
@@ -63,6 +72,14 @@ func (s *serialPort) exchangePayloadLocked(payload []byte, cmdName string) ([]by
 		return nil, fmt.Errorf("write: %w", err)
 	}
 
+	if timeout <= 0 {
+		timeout = readTimeout
+	}
+	if err := s.port.SetReadTimeout(timeout); err != nil {
+		return nil, fmt.Errorf("set read timeout: %w", err)
+	}
+	defer func() { _ = s.port.SetReadTimeout(readTimeout) }()
+
 	respPayload, err := uartframe.ReadFrame(s.port, nil)
 	if err != nil {
 		return nil, fmt.Errorf("read response: %w", err)

goTool/webui/index.html

@@ -200,6 +200,10 @@
                 <dd class="col-7" x-text="state.master.running_partition || '—'"></dd>
                 <dt class="col-5 text-muted">Deadzone</dt>
                 <dd class="col-7" x-text="state.master.deadzone != null ? state.master.deadzone + ' LSB' : '—'"></dd>
+                <dt class="col-5 text-muted">LiPo 1</dt>
+                <dd class="col-7" x-text="formatLipo(state.master?.lipo1)"></dd>
+                <dt class="col-5 text-muted">LiPo 2</dt>
+                <dd class="col-7" x-text="formatLipo(state.master?.lipo2)"></dd>
               </dl>
             </template>
             <template x-if="state.master && !state.master.ok">
@@ -280,13 +284,14 @@
                     <th>Status</th>
                     <th>Deadzone</th>
                     <th>Accel (LSB)</th>
+                    <th>Akku</th>
                     <th>Stream</th>
                     <th>Aktion</th>
                   </tr>
                 </thead>
                 <tbody>
                   <template x-if="!(state.clients || []).length">
-                    <tr><td colspan="8" class="text-muted text-center py-4">No clients</td></tr>
+                    <tr><td colspan="9" class="text-muted text-center py-4">No clients</td></tr>
                   </template>
                   <template x-for="c in (state.clients || [])" :key="c.id + c.mac">
                     <tr>
@@ -305,6 +310,7 @@
                               x-text="formatAccel(c)"
                               :title="accelTitle(c)"></span>
                       </td>
+                      <td class="small" x-text="formatLipoPair(c)" :title="lipoTitle(c)"></td>
                       <td>
                         <button type="button"
                                 class="btn btn-sm"
@@ -576,9 +582,14 @@
         connect() {
           const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
           const url = proto + '//' + location.host + '/ws';
+          if (this._batteryTimer) clearInterval(this._batteryTimer);
+          this._batteryTimer = setInterval(() => this.refreshBattery(), 5000);
           const connect = () => {
             this.ws = new WebSocket(url);
-            this.ws.onopen = () => { this.wsConnected = true; };
+            this.ws.onopen = () => {
+              this.wsConnected = true;
+              this.refreshBattery();
+            };
             this.ws.onclose = () => {
               this.wsConnected = false;
               setTimeout(connect, 2000);
@@ -590,7 +601,13 @@
                   this.applyOTAProgress(msg);
                   return;
                 }
+                if (msg.type === 'battery_status') {
+                  if (msg.samples?.length) this.applyBatterySamples(msg.samples);
+                  return;
+                }
+                const prev = this.state;
                 this.state = msg;
+                this.preserveBatteryInState(prev, this.state);
                 if (msg.master?.deadzone != null) {
                   this.masterDz = msg.master.deadzone;
                 }
@@ -604,10 +621,87 @@
           };
           connect();
         },
+        preserveBatteryInState(prev, next) {
+          if (!prev || !next) return;
+          const keepLipo = (oldL, newL) => {
+            if (newL?.valid) return newL;
+            if (oldL?.valid) return oldL;
+            return newL ?? oldL;
+          };
+          const keepAge = (oldAge, newAge, hasValid) => {
+            if (hasValid && newAge != null) return newAge;
+            if (oldAge != null && !hasValid) return oldAge;
+            return newAge ?? oldAge;
+          };
+          if (next.master) {
+            const pm = prev.master || {};
+            const l1 = keepLipo(pm.lipo1, next.master.lipo1);
+            const l2 = keepLipo(pm.lipo2, next.master.lipo2);
+            next.master.lipo1 = l1;
+            next.master.lipo2 = l2;
+            next.master.battery_age_ms = keepAge(
+              pm.battery_age_ms, next.master.battery_age_ms, !!(l1?.valid || l2?.valid));
+          }
+          if (!Array.isArray(next.clients)) return;
+          const prevById = Object.fromEntries((prev.clients || []).map((c) => [c.id, c]));
+          next.clients = next.clients.map((c) => {
+            const p = prevById[c.id];
+            if (!p) return c;
+            const l1 = keepLipo(p.lipo1, c.lipo1);
+            const l2 = keepLipo(p.lipo2, c.lipo2);
+            return {
+              ...c,
+              lipo1: l1,
+              lipo2: l2,
+              battery_age_ms: keepAge(p.battery_age_ms, c.battery_age_ms, !!(l1?.valid || l2?.valid))
+            };
+          });
+        },
+        applyBatterySamples(samples) {
+          if (!samples?.length) return;
+          for (const s of samples) {
+            if (s.client_id === 0) {
+              if (!this.state.master) this.state.master = {};
+              this.state.master.lipo1 = s.lipo1;
+              this.state.master.lipo2 = s.lipo2;
+              this.state.master.battery_age_ms = s.age_ms;
+              continue;
+            }
+            const c = (this.state.clients || []).find((x) => x.id === s.client_id);
+            if (c) {
+              c.lipo1 = s.lipo1;
+              c.lipo2 = s.lipo2;
+              c.battery_age_ms = s.age_ms;
+            }
+          }
+        },
+        async refreshBattery() {
+          if (!this.state?.uart_connected) return;
+          try {
+            const r = await fetch('/api/battery?all_clients=1');
+            if (!r.ok) return;
+            const data = await r.json();
+            if (data.samples?.length) this.applyBatterySamples(data.samples);
+          } catch (_) {}
+        },
         formatMac(hex) {
           if (!hex || hex.length !== 12) return hex || '';
           return hex.match(/.{2}/g).join(':');
         },
+        formatLipo(l) {
+          if (!l?.valid) return '—';
+          const v = (l.voltage_mv / 1000).toFixed(2);
+          return l.percent != null ? `${v} V (${l.percent}%)` : `${v} V`;
+        },
+        formatLipoPair(c) {
+          return `1: ${this.formatLipo(c?.lipo1)} · 2: ${this.formatLipo(c?.lipo2)}`;
+        },
+        lipoTitle(c) {
+          if (!c?.lipo1?.valid && !c?.lipo2?.valid) return 'Keine ADC-Daten (Cache ~30 s)';
+          let t = `LiPo1 ${c.lipo1?.voltage_mv ?? '—'} mV, LiPo2 ${c.lipo2?.voltage_mv ?? '—'} mV`;
+          if (c.battery_age_ms != null) t += `, Alter ${c.battery_age_ms} ms`;
+          return t;
+        },
         formatAccel(c) {
           if (!c?.accel_stream) return '—';
           if (!c?.accel_valid) return '…';

main/CMakeLists.txt

@@ -25,6 +25,7 @@ idf_component_register(
   "cmd/cmd_restart.c"
   "pod_reboot.c"
   "cmd/cmd_led_ring.c"
+  "cmd/cmd_battery.c"
   "cmd/cmd_ota.c"
   "cmd/cmd_ota_slave_progress.c"
   "ota_uart.c"

main/README.md

@@ -116,6 +116,7 @@ Schema: `proto/esp_now_messages.proto`. Encode/decode: `esp_now_proto.c`. The ES
 | `ESPNOW_FIND_ME` | Master → slave | `EspNowFindMe` (`client_id` filter) — LED locate sequence |
 | `ESPNOW_RESTART` | Master → slave | `EspNowRestart` (`client_id` filter) — reboot slave |
 | `ESPNOW_ACCEL_SAMPLE` | Slave → master | `EspNowAccelSample` (`slave_id`, `x`, `y`, `z` raw LSB) — ~every 16 ms |
+| `ESPNOW_BATTERY_REPORT` | Slave → master | `EspNowBatteryReport` (`client_id`, `lipo1/2` mV) — ~every 30 s; cached in `client_registry` |
 | `ESPNOW_OTA_START` | Master → slave (unicast) | `EspNowOtaStart` (`total_size`) |
 | `ESPNOW_OTA_PAYLOAD` | Master → slave | `EspNowOtaPayload` (`seq`, up to 200 B `data`) |
 | `ESPNOW_OTA_END` | Master → slave | `EspNowOtaEnd` |
@@ -210,6 +211,7 @@ Host and master speak nanopb-encoded `UartMessage` inside UART frames (byte 0 =
 | 6 | `ACCEL_DEADZONE` | Implemented (`cmd/cmd_accel_deadzone.c`) — get/set accel filter LSB |
 | 7 | `ESPNOW_UNICAST_TEST` | Implemented (`cmd/cmd_espnow_unicast_test.c`) |
 | 8 | `LED_RING` | Implemented (`cmd/cmd_led_ring.c`) — ring progress bar (0–100 %, RGB, intensity) |
+| 26 | `BATTERY_STATUS` | Implemented (`cmd/cmd_battery.c`) — cached LiPo 1/2 per pod from `client_registry` (UART read, no slave round-trip) |
 | 16 | `OTA_START` | Implemented (`cmd/cmd_ota.c`) — begin UART OTA on inactive slot |
 | 17 | `OTA_PAYLOAD` | Implemented — up to 200 B per frame; device buffers 4 KiB |
 | 18 | `OTA_END` | Implemented — flush, `esp_ota_end`, push image to slaves via ESP-NOW, set boot |
@@ -370,6 +372,18 @@ go run . -port /dev/ttyUSB0 restart
 go run . -port /dev/ttyUSB0 restart -client 16
 ```
 
+### BATTERY_STATUS command
+
+Read **cached** LiPo ADC values on the **master** (master local + one entry per registered slave). Slaves push `ESPNOW_BATTERY_REPORT` every **30 s**; the master stores them in `client_registry` (`lipo1/2_valid`, `lipo1/2_mv`, `battery_updated_at`). The master refreshes its own pack on the same interval in `master_monitor_task`.
+
+**Request:** framed `26` + optional `battery_status_request` (`client_id`, `all_clients`).
+
+**Response:** `battery_status_response` with `samples[]` (`client_id`, `lipo1`, `lipo2`, `age_ms`).
+
+```bash
+# Host / goTool: all_clients returns master (id 0) + slaves from cache
+```
+
 ### LED_RING command
 
 Control the 95-LED ring from the host. The firmware **does not** animate digits locally; only UART updates the display.

main/board_input.c

@@ -6,7 +6,7 @@
 #include "freertos/FreeRTOS.h"
 #include "freertos/idf_additions.h"
 #include "freertos/queue.h"
-#include <stdint.h>
+#include <string.h>
 
 static const char *TAG_BTN = "[BTN]";
 static const char *TAG_LIPO = "[LIPO]";
@@ -14,6 +14,8 @@ static const char *TAG_LIPO = "[LIPO]";
 #define LIPO_SAMPLE_INTERVAL_MS 10000
 #define BUTTON_QUEUE_LEN 4
 #define BUTTON_DEBOUNCE_MS 80
+#define LIPO_ADC_FULL_SCALE_MV 3300
+#define LIPO_ADC_MAX_RAW 4095
 
 static QueueHandle_t s_button_queue;
 static adc_oneshot_unit_handle_t s_adc;
@@ -47,33 +49,51 @@ static esp_err_t adc_init_channel(int gpio, adc_channel_t *out_ch, bool *out_ok)
   return ESP_OK;
 }
 
+static uint32_t raw_to_mv(int raw) {
+  if (raw < 0) {
+    return 0;
+  }
+  return (uint32_t)((raw * LIPO_ADC_FULL_SCALE_MV) / LIPO_ADC_MAX_RAW);
+}
+
+static void sample_one_channel(adc_channel_t ch, bool ok, uint32_t *mv_out,
+                               bool *valid_out) {
+  *valid_out = false;
+  *mv_out = 0;
+  if (!ok || s_adc == NULL) {
+    return;
+  }
+  int raw = 0;
+  if (adc_oneshot_read(s_adc, ch, &raw) == ESP_OK) {
+    *valid_out = true;
+    *mv_out = raw_to_mv(raw);
+  }
+}
+
+void board_input_read_lipo(board_lipo_reading_t *out) {
+  if (out == NULL) {
+    return;
+  }
+  memset(out, 0, sizeof(*out));
+  sample_one_channel(s_lipo1_ch, s_lipo1_ok, &out->lipo1_mv, &out->lipo1_valid);
+  sample_one_channel(s_lipo2_ch, s_lipo2_ok, &out->lipo2_mv, &out->lipo2_valid);
+}
+
 static void lipo_monitor_task(void *param) {
   (void)param;
 
   ESP_LOGI(TAG_LIPO, "monitor task (interval %d ms)", LIPO_SAMPLE_INTERVAL_MS);
 
   while (1) {
-    int raw1 = -1;
+    board_lipo_reading_t reading;
-    int raw2 = -1;
+    board_input_read_lipo(&reading);
-    int mv1 = -1;
-    int mv2 = -1;
-
-    if (s_lipo1_ok) {
-      raw1 = 0;
-      if (adc_oneshot_read(s_adc, s_lipo1_ch, &raw1) == ESP_OK) {
-        mv1 = (raw1 * 3300) / 4095;
-      }
-    }
-    if (s_lipo2_ok) {
-      raw2 = 0;
-      if (adc_oneshot_read(s_adc, s_lipo2_ch, &raw2) == ESP_OK) {
-        mv2 = (raw2 * 3300) / 4095;
-      }
-    }
 
     ESP_LOGI(TAG_LIPO,
-             "LIPO1 GPIO%d raw=%d (~%d mV)  LIPO2 GPIO%d raw=%d (~%d mV)",
+             "LIPO1 GPIO%d %s %lu mV  LIPO2 GPIO%d %s %lu mV",
-             V_LIPO_1_GPIO, raw1, mv1, V_LIPO_2_GPIO, raw2, mv2);
+             V_LIPO_1_GPIO, reading.lipo1_valid ? "ok" : "n/a",
+             (unsigned long)reading.lipo1_mv, V_LIPO_2_GPIO,
+             reading.lipo2_valid ? "ok" : "n/a",
+             (unsigned long)reading.lipo2_mv);
 
     vTaskDelay(pdMS_TO_TICKS(LIPO_SAMPLE_INTERVAL_MS));
   }

main/board_input.h

@@ -1,12 +1,25 @@
 #ifndef BOARD_INPUT_H
 #define BOARD_INPUT_H
 
+#include <stdbool.h>
+#include <stdint.h>
+
 #include "esp_err.h"
 
+typedef struct {
+  bool lipo1_valid;
+  bool lipo2_valid;
+  uint32_t lipo1_mv;
+  uint32_t lipo2_mv;
+} board_lipo_reading_t;
+
 /**
- * Button (log on press) and LiPo ADC sampling (log every 10 s).
+ * Button (log on press) and LiPo ADC sampling (background log every 10 s).
  * TODO: Pin assignments come from powerpod.h and may not match final hardware yet.
  */
 esp_err_t board_input_init(void);
 
+/** On-demand ADC read of both LiPo sense inputs (if configured). */
+void board_input_read_lipo(board_lipo_reading_t *out);
+
 #endif

main/client_registry.c

@@ -14,6 +14,11 @@ typedef struct {
 
 static client_slot_t s_clients[CLIENT_REGISTRY_MAX];
 
+static struct {
+  board_lipo_reading_t reading;
+  uint32_t updated_at;
+} s_master_battery;
+
 uint32_t client_registry_now_ms(void) {
   return (uint32_t)(xTaskGetTickCount() * portTICK_PERIOD_MS);
 }
@@ -320,6 +325,64 @@ esp_err_t client_registry_update_accel(const uint8_t mac[CLIENT_MAC_LEN],
   return ESP_OK;
 }
 
+void client_registry_set_master_battery(const board_lipo_reading_t *reading) {
+  if (reading == NULL) {
+    return;
+  }
+  s_master_battery.reading = *reading;
+  s_master_battery.updated_at = now_ms();
+}
+
+bool client_registry_get_master_battery(board_lipo_reading_t *reading_out,
+                                        uint32_t *age_ms_out) {
+  if (reading_out == NULL) {
+    return false;
+  }
+  *reading_out = s_master_battery.reading;
+  if (age_ms_out != NULL) {
+    *age_ms_out = client_registry_ms_since(s_master_battery.updated_at);
+  }
+  return s_master_battery.updated_at != 0;
+}
+
+esp_err_t client_registry_update_battery(const uint8_t mac[CLIENT_MAC_LEN],
+                                         uint32_t slave_id, bool lipo1_valid,
+                                         uint32_t lipo1_mv, bool lipo2_valid,
+                                         uint32_t lipo2_mv) {
+  if (mac == NULL) {
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  client_slot_t *slot = find_slot(mac);
+  if (slot == NULL) {
+    bool is_new = false;
+    esp_err_t err = client_registry_upsert(mac, slave_id, 0, true, false, &is_new);
+    if (err != ESP_OK) {
+      return err;
+    }
+    slot = find_slot(mac);
+    if (slot == NULL) {
+      return ESP_ERR_NOT_FOUND;
+    }
+    ESP_LOGI(TAG, "battery auto-registered id=%lu (report before heartbeat)",
+             (unsigned long)slave_id);
+  }
+
+  if (slot->info.id != slave_id) {
+    ESP_LOGW(TAG, "battery id %lu → %lu for mac %02x:…:%02x",
+             (unsigned long)slot->info.id, (unsigned long)slave_id, mac[0],
+             mac[5]);
+    slot->info.id = slave_id;
+  }
+
+  slot->info.lipo1_valid = lipo1_valid;
+  slot->info.lipo2_valid = lipo2_valid;
+  slot->info.lipo1_mv = lipo1_mv;
+  slot->info.lipo2_mv = lipo2_mv;
+  slot->info.battery_updated_at = now_ms();
+  return ESP_OK;
+}
+
 const client_info_t *client_registry_at(size_t index) {
   size_t n = 0;
   for (size_t i = 0; i < CLIENT_REGISTRY_MAX; i++) {

main/client_registry.h

@@ -1,6 +1,7 @@
 #ifndef CLIENT_REGISTRY_H
 #define CLIENT_REGISTRY_H
 
+#include "board_input.h"
 #include "esp_err.h"
 #include <stdbool.h>
 #include <stddef.h>
@@ -29,6 +30,12 @@ typedef struct {
   uint32_t accel_updated_at;
   /** Host-enabled ESP-NOW accel stream to master. */
   bool accel_stream_enabled;
+  /** Latest LiPo ADC from slave ESP-NOW battery report (~30 s). */
+  bool lipo1_valid;
+  bool lipo2_valid;
+  uint32_t lipo1_mv;
+  uint32_t lipo2_mv;
+  uint32_t battery_updated_at;
 } client_info_t;
 
 #define CLIENT_REGISTRY_DEFAULT_ACCEL_DEADZONE 100u
@@ -80,4 +87,15 @@ esp_err_t client_registry_set_accel_stream(uint32_t client_id, bool enabled);
 esp_err_t client_registry_get_accel_stream(uint32_t client_id, bool *enabled_out);
 size_t client_registry_set_accel_stream_all(bool enabled);
 
+/** Master local LiPo (client_id 0 in UART battery responses). */
+void client_registry_set_master_battery(const board_lipo_reading_t *reading);
+bool client_registry_get_master_battery(board_lipo_reading_t *reading_out,
+                                        uint32_t *age_ms_out);
+
+/** Store latest battery report from a slave (matched by sender MAC). */
+esp_err_t client_registry_update_battery(const uint8_t mac[CLIENT_MAC_LEN],
+                                         uint32_t slave_id, bool lipo1_valid,
+                                         uint32_t lipo1_mv, bool lipo2_valid,
+                                         uint32_t lipo2_mv);
+
 #endif

main/cmd/cmd_battery.c

@@ -0,0 +1,119 @@
+#include "cmd_battery.h"
+#include "board_input.h"
+#include "client_registry.h"
+#include "esp_log.h"
+#include "uart_cmd.h"
+
+static const char *TAG = "[BATTERY]";
+
+static void fill_lipo(alox_LipoReading *dst, bool *has_dst, bool valid,
+                      uint32_t mv) {
+  if (dst == NULL || has_dst == NULL) {
+    return;
+  }
+  *has_dst = true;
+  dst->valid = valid;
+  dst->voltage_mv = valid ? mv : 0;
+}
+
+static bool append_battery_sample(alox_BatteryStatusResponse *resp,
+                                  uint32_t client_id, bool lipo1_valid,
+                                  uint32_t lipo1_mv, bool lipo2_valid,
+                                  uint32_t lipo2_mv, uint32_t age_ms) {
+  if (resp->samples_count >=
+      sizeof(resp->samples) / sizeof(resp->samples[0])) {
+    return false;
+  }
+
+  alox_BatterySample *sample = &resp->samples[resp->samples_count++];
+  sample->client_id = client_id;
+  fill_lipo(&sample->lipo1, &sample->has_lipo1, lipo1_valid, lipo1_mv);
+  fill_lipo(&sample->lipo2, &sample->has_lipo2, lipo2_valid, lipo2_mv);
+  sample->age_ms = age_ms;
+  return lipo1_valid || lipo2_valid;
+}
+
+static bool append_master_cached(alox_BatteryStatusResponse *resp) {
+  board_lipo_reading_t reading;
+  uint32_t age_ms = 0;
+
+  if (!client_registry_get_master_battery(&reading, &age_ms)) {
+    board_input_read_lipo(&reading);
+    client_registry_set_master_battery(&reading);
+    age_ms = 0;
+  }
+
+  return append_battery_sample(resp, 0, reading.lipo1_valid, reading.lipo1_mv,
+                               reading.lipo2_valid, reading.lipo2_mv, age_ms);
+}
+
+static bool append_slave_cached(alox_BatteryStatusResponse *resp,
+                                const client_info_t *client) {
+  if (client == NULL) {
+    return false;
+  }
+  if (client->battery_updated_at == 0) {
+    return false;
+  }
+
+  return append_battery_sample(
+      resp, client->id, client->lipo1_valid, client->lipo1_mv,
+      client->lipo2_valid, client->lipo2_mv,
+      client_registry_ms_since(client->battery_updated_at));
+}
+
+static void handle_battery_status(const uint8_t *data, size_t len) {
+  alox_BatteryStatusRequest req = alox_BatteryStatusRequest_init_zero;
+
+  if (len > 0) {
+    alox_UartMessage uart_msg;
+    if (uart_cmd_decode(data, len, &uart_msg) == ESP_OK) {
+      const alox_BatteryStatusRequest *req_ptr = UART_CMD_REQ(
+          &uart_msg, alox_UartMessage_battery_status_request_tag,
+          battery_status_request);
+      if (req_ptr != NULL) {
+        req = *req_ptr;
+      }
+    }
+  }
+
+  alox_UartMessage response;
+  uart_cmd_init_response(&response, alox_MessageType_BATTERY_STATUS,
+                         alox_UartMessage_battery_status_response_tag);
+  alox_BatteryStatusResponse *resp =
+      &response.payload.battery_status_response;
+  resp->success = false;
+  resp->samples_count = 0;
+
+  bool any = false;
+
+  if (req.all_clients) {
+    any |= append_master_cached(resp);
+    for (size_t i = 0; i < client_registry_count(); i++) {
+      const client_info_t *client = client_registry_at(i);
+      if (client == NULL) {
+        continue;
+      }
+      any |= append_slave_cached(resp, client);
+    }
+    ESP_LOGI(TAG, "battery cache all_clients → %u samples",
+             (unsigned)resp->samples_count);
+  } else if (req.client_id == 0) {
+    any = append_master_cached(resp);
+    ESP_LOGI(TAG, "battery cache master");
+  } else {
+    const client_info_t *client = client_registry_find_by_id(req.client_id);
+    if (client != NULL) {
+      any = append_slave_cached(resp, client);
+    } else {
+      ESP_LOGW(TAG, "client %lu not in registry", (unsigned long)req.client_id);
+    }
+  }
+
+  resp->success = any;
+  uart_cmd_send(&response, TAG);
+}
+
+void cmd_battery_register(void) {
+  uart_cmd_register(alox_MessageType_BATTERY_STATUS, handle_battery_status);
+}

main/cmd/cmd_battery.h

@@ -0,0 +1,6 @@
+#ifndef CMD_BATTERY_H
+#define CMD_BATTERY_H
+
+void cmd_battery_register(void);
+
+#endif

main/cmd/cmd_handler.c

@@ -52,6 +52,8 @@ static const char *message_type_name(uint16_t id) {
     return "ACCEL_SNAPSHOT";
   case alox_MessageType_ACCEL_STREAM:
     return "ACCEL_STREAM";
+  case alox_MessageType_BATTERY_STATUS:
+    return "BATTERY_STATUS";
   default:
     return "UNKNOWN";
   }

main/esp_now_comm.c

@@ -1,6 +1,7 @@
 #include "bosch456.h"
 #include "client_registry.h"
 #include "esp_now_comm.h"
+#include "board_input.h"
 #include "cmd_led_ring.h"
 #include "led_ring.h"
 #include "ota_espnow.h"
@@ -48,6 +49,16 @@ static uint32_t s_last_discover_ms;
 static SemaphoreHandle_t s_send_done;
 static bool s_send_cb_ready;
 
+#define ESPNOW_BATTERY_INTERVAL_MS 30000
+#define SLAVE_BATTERY_AFTER_JOIN_MS 150
+
+typedef enum {
+  SLAVE_TX_SLAVE_INFO = 1,
+  SLAVE_TX_BATTERY,
+} slave_tx_op_t;
+
+static QueueHandle_t s_slave_tx_queue;
+
 static uint32_t now_ms(void) {
   return (uint32_t)(xTaskGetTickCount() * portTICK_PERIOD_MS);
 }
@@ -90,6 +101,7 @@ static esp_err_t ensure_broadcast_peer(void) { return ensure_peer(ESPNOW_BCAST);
 
 static esp_err_t send_message_ex(const uint8_t *dest_mac,
                                  const alox_EspNowMessage *msg, bool wait_done);
+static void slave_send_battery_report_to_master(void);
 
 static void fill_presence(alox_EspNowSlavePresence *presence) {
   presence->network = s_config.network;
@@ -210,6 +222,21 @@ static esp_err_t send_find_me(const uint8_t *dest_mac, uint32_t client_id) {
   return send_message(dest_mac, &msg);
 }
 
+static esp_err_t send_battery_report(const uint8_t *dest_mac,
+                                     const alox_EspNowBatteryReport *report) {
+  if (report == NULL) {
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  alox_EspNowMessage msg = alox_EspNowMessage_init_zero;
+
+  msg.type = alox_EspNowMessageType_ESPNOW_BATTERY_REPORT;
+  msg.which_payload = alox_EspNowMessage_battery_report_tag;
+  msg.payload.battery_report = *report;
+
+  return send_message(dest_mac, &msg);
+}
+
 static esp_err_t send_led_ring(const uint8_t *dest_mac, uint32_t client_id,
                                const alox_LedRingProgressRequest *req) {
   if (req == NULL) {
@@ -470,6 +497,47 @@ static void slave_reset_join(void) {
   s_accel_stream_enabled = false;
   memset(s_master_mac, 0, sizeof(s_master_mac));
   s_last_discover_ms = 0;
+  if (s_slave_tx_queue != NULL) {
+    xQueueReset(s_slave_tx_queue);
+  }
+}
+
+static void slave_queue_tx(slave_tx_op_t op) {
+  if (s_slave_tx_queue == NULL) {
+    return;
+  }
+  if (xQueueSend(s_slave_tx_queue, &op, 0) != pdTRUE) {
+    ESP_LOGW(TAG, "slave tx queue full (op=%d)", (int)op);
+  }
+}
+
+static void slave_tx_task(void *param) {
+  (void)param;
+  slave_tx_op_t op;
+
+  ESP_LOGI(TAG, "slave tx task ready");
+
+  while (1) {
+    if (xQueueReceive(s_slave_tx_queue, &op, portMAX_DELAY) != pdTRUE) {
+      continue;
+    }
+
+    if (!s_slave_joined) {
+      continue;
+    }
+
+    switch (op) {
+    case SLAVE_TX_SLAVE_INFO:
+      send_presence(s_master_mac, alox_EspNowMessageType_ESPNOW_SLAVE_INFO);
+      break;
+    case SLAVE_TX_BATTERY:
+      vTaskDelay(pdMS_TO_TICKS(SLAVE_BATTERY_AFTER_JOIN_MS));
+      slave_send_battery_report_to_master();
+      break;
+    default:
+      break;
+    }
+  }
 }
 
 static void handle_slave_unicast_test(const uint8_t *master_mac,
@@ -499,6 +567,77 @@ static void handle_slave_restart(const uint8_t *master_mac,
   pod_schedule_restart();
 }
 
+static void slave_send_battery_report_to_master(void) {
+  if (!s_slave_joined) {
+    return;
+  }
+
+  board_lipo_reading_t reading;
+  board_input_read_lipo(&reading);
+
+  alox_EspNowBatteryReport report = alox_EspNowBatteryReport_init_zero;
+  report.client_id = s_own_mac[5];
+  report.lipo1_valid = reading.lipo1_valid;
+  report.lipo2_valid = reading.lipo2_valid;
+  report.lipo1_mv = reading.lipo1_mv;
+  report.lipo2_mv = reading.lipo2_mv;
+
+  esp_err_t err = send_battery_report(s_master_mac, &report);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "battery report send failed id=%lu: %s",
+             (unsigned long)report.client_id, esp_err_to_name(err));
+  } else {
+    ESP_LOGI(TAG, "battery report sent id=%lu L1=%s %lu mV L2=%s %lu mV",
+             (unsigned long)report.client_id,
+             report.lipo1_valid ? "ok" : "n/a",
+             (unsigned long)report.lipo1_mv,
+             report.lipo2_valid ? "ok" : "n/a",
+             (unsigned long)report.lipo2_mv);
+  }
+}
+
+static void handle_slave_battery_query(const uint8_t *master_mac,
+                                       const alox_EspNowBatteryQuery *query) {
+  uint32_t my_id = s_own_mac[5];
+
+  if (query->client_id != 0 && query->client_id != my_id) {
+    return;
+  }
+
+  if (s_slave_joined && !mac_equal(master_mac, s_master_mac)) {
+    return;
+  }
+
+  slave_send_battery_report_to_master();
+}
+
+static void handle_master_battery_report(const uint8_t *mac,
+                                         const alox_EspNowBatteryReport *report) {
+  if (report == NULL || mac == NULL) {
+    return;
+  }
+
+  esp_err_t err = client_registry_update_battery(
+      mac, report->client_id, report->lipo1_valid, report->lipo1_mv,
+      report->lipo2_valid, report->lipo2_mv);
+  if (err == ESP_ERR_NOT_FOUND) {
+    ESP_LOGW(TAG, "battery report from unregistered slave id=%lu",
+             (unsigned long)report->client_id);
+    return;
+  }
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "battery report id=%lu rejected: %s",
+             (unsigned long)report->client_id, esp_err_to_name(err));
+    return;
+  }
+
+  ESP_LOGI(TAG, "battery cached id=%lu L1=%s %lu mV L2=%s %lu mV",
+           (unsigned long)report->client_id,
+           report->lipo1_valid ? "ok" : "n/a",
+           (unsigned long)report->lipo1_mv, report->lipo2_valid ? "ok" : "n/a",
+           (unsigned long)report->lipo2_mv);
+}
+
 static void handle_slave_led_ring(const uint8_t *master_mac,
                                   const alox_EspNowLedRing *msg) {
   uint32_t my_id = s_own_mac[5];
@@ -670,7 +809,9 @@ static void handle_discover(const uint8_t *sender_mac,
   ESP_LOGI(TAG, "joined network %u, master %s", (unsigned)discover->network,
            mac_str);
 
-  send_presence(sender_mac, alox_EspNowMessageType_ESPNOW_SLAVE_INFO);
+  /* Do not esp_now_send from recv callback — defer to slave_tx_task. */
+  slave_queue_tx(SLAVE_TX_SLAVE_INFO);
+  slave_queue_tx(SLAVE_TX_BATTERY);
 }
 
 static void slave_check_master_timeout(void) {
@@ -716,6 +857,7 @@ static void slave_accel_stream_task(void *param) {
 
 static void slave_heartbeat_task(void *param) {
   (void)param;
+  uint32_t last_battery_ms = 0;
 
   ESP_LOGI(TAG, "slave heartbeat task (interval %u ms)",
            (unsigned)ESPNOW_HEARTBEAT_INTERVAL_MS);
@@ -726,22 +868,43 @@ static void slave_heartbeat_task(void *param) {
     slave_check_master_timeout();
 
     if (!s_slave_joined) {
+      last_battery_ms = 0;
       continue;
     }
 
     send_presence(s_master_mac, alox_EspNowMessageType_ESPNOW_HEARTBEAT);
+
+    uint32_t now = now_ms();
+    if (last_battery_ms == 0 ||
+        (now - last_battery_ms) >= ESPNOW_BATTERY_INTERVAL_MS) {
+      slave_send_battery_report_to_master();
+      last_battery_ms = now;
+    }
   }
 }
 
 static void master_monitor_task(void *param) {
   (void)param;
+  uint32_t last_local_battery_ms = 0;
 
   ESP_LOGI(TAG, "master monitor task (timeout %u ms)",
            (unsigned)ESPNOW_CLIENT_TIMEOUT_MS);
 
+  board_lipo_reading_t reading;
+  board_input_read_lipo(&reading);
+  client_registry_set_master_battery(&reading);
+  last_local_battery_ms = now_ms();
+
   while (1) {
     vTaskDelay(pdMS_TO_TICKS(ESPNOW_HEARTBEAT_INTERVAL_MS));
     client_registry_check_timeouts(ESPNOW_CLIENT_TIMEOUT_MS);
+
+    uint32_t t = now_ms();
+    if (t - last_local_battery_ms >= ESPNOW_BATTERY_INTERVAL_MS) {
+      board_input_read_lipo(&reading);
+      client_registry_set_master_battery(&reading);
+      last_local_battery_ms = t;
+    }
   }
 }
 
@@ -779,6 +942,12 @@ static void espnow_recv_cb(const esp_now_recv_info_t *info, const uint8_t *data,
       }
       handle_slave_accel_stream(info->src_addr, &msg.payload.accel_stream);
       break;
+    case alox_EspNowMessage_battery_query_tag:
+      if (!s_slave_joined || !mac_equal(info->src_addr, s_master_mac)) {
+        break;
+      }
+      handle_slave_battery_query(info->src_addr, &msg.payload.battery_query);
+      break;
     case alox_EspNowMessage_led_ring_tag:
       if (!s_slave_joined || !mac_equal(info->src_addr, s_master_mac)) {
         break;
@@ -838,6 +1007,17 @@ static void espnow_recv_cb(const esp_now_recv_info_t *info, const uint8_t *data,
     return;
   }
 
+  if (msg.which_payload == alox_EspNowMessage_battery_report_tag) {
+    ensure_peer(info->src_addr);
+    handle_master_battery_report(info->src_addr, &msg.payload.battery_report);
+    return;
+  }
+
+  if (msg.type == alox_EspNowMessageType_ESPNOW_BATTERY_REPORT &&
+      msg.which_payload != alox_EspNowMessage_battery_report_tag) {
+    ESP_LOGW(TAG, "master: BATTERY_REPORT type but which=%u", msg.which_payload);
+  }
+
   const alox_EspNowSlavePresence *presence = esp_now_proto_get_presence(&msg);
   if (presence != NULL) {
     /* Registry key is the ESP-NOW sender MAC, not the optional protobuf mac field. */
@@ -933,6 +1113,16 @@ esp_err_t esp_now_comm_init(const app_config_t *config) {
       return ESP_FAIL;
     }
   } else {
+    s_slave_tx_queue = xQueueCreate(4, sizeof(slave_tx_op_t));
+    if (s_slave_tx_queue == NULL) {
+      ESP_LOGE(TAG, "failed to create slave tx queue");
+      return ESP_ERR_NO_MEM;
+    }
+    if (xTaskCreate(slave_tx_task, "espnow_stx", 4096, NULL, 5, NULL) !=
+        pdPASS) {
+      ESP_LOGE(TAG, "failed to create slave tx task");
+      return ESP_FAIL;
+    }
     if (xTaskCreate(slave_heartbeat_task, "espnow_hb", 4096, NULL, 4, NULL) !=
         pdPASS) {
       ESP_LOGE(TAG, "failed to create heartbeat task");

main/esp_now_comm.h

@@ -4,6 +4,7 @@
 #include "app_config.h"
 #include "client_registry.h"
 #include "esp_err.h"
+#include "esp_now_messages.pb.h"
 #include "uart_messages.pb.h"
 
 esp_err_t esp_now_comm_init(const app_config_t *config);

main/powerpod.c

@@ -11,6 +11,7 @@
 #include "cmd_ota.h"
 #include "cmd_ota_slave_progress.h"
 #include "cmd_led_ring.h"
+#include "cmd_battery.h"
 #include "esp_now_comm.h"
 #include "powerpod.h"
 #include "driver/gpio.h"
@@ -163,6 +164,8 @@ void app_main(void) {
   ESP_LOGI(TAG, "Running Partition: %s (OTA slot %d)",
            app_config.running_partition, ota_slot);
 
+  board_input_init();
+
   err = esp_now_comm_init(&app_config);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "ESP-NOW init failed: %s", esp_err_to_name(err));
@@ -170,8 +173,6 @@ void app_main(void) {
 
   led_ring_init();
 
-  board_input_init();
-
   if (app_config.master) {
     cmd_queue = xQueueCreate(64, sizeof(generic_msg_t));
     init_cmdHandler(cmd_queue);
@@ -185,6 +186,7 @@ void app_main(void) {
     cmd_espnow_find_me_register();
     cmd_restart_register();
     cmd_led_ring_register();
+    cmd_battery_register();
     cmd_ota_register();
     cmd_ota_slave_progress_register();
   }

main/proto/esp_now_messages.pb.c

@@ -30,6 +30,12 @@ PB_BIND(alox_EspNowAccelStream, alox_EspNowAccelStream, AUTO)
 PB_BIND(alox_EspNowAccelSample, alox_EspNowAccelSample, AUTO)
 
 
+PB_BIND(alox_EspNowBatteryQuery, alox_EspNowBatteryQuery, AUTO)
+
+
+PB_BIND(alox_EspNowBatteryReport, alox_EspNowBatteryReport, AUTO)
+
+
 PB_BIND(alox_EspNowLedRing, alox_EspNowLedRing, AUTO)
 
 

main/proto/esp_now_messages.pb.h

@@ -25,7 +25,9 @@ typedef enum _alox_EspNowMessageType {
     alox_EspNowMessageType_ESPNOW_RESTART = 11,
     alox_EspNowMessageType_ESPNOW_ACCEL_SAMPLE = 12,
     alox_EspNowMessageType_ESPNOW_SET_ACCEL_STREAM = 13,
-    alox_EspNowMessageType_ESPNOW_LED_RING = 14
+    alox_EspNowMessageType_ESPNOW_LED_RING = 14,
+    alox_EspNowMessageType_ESPNOW_BATTERY_QUERY = 15,
+    alox_EspNowMessageType_ESPNOW_BATTERY_REPORT = 16
 } alox_EspNowMessageType;
 
 /* Struct definitions */
@@ -76,6 +78,20 @@ typedef struct _alox_EspNowAccelSample {
     int32_t z;
 } alox_EspNowAccelSample;
 
+/* * Master → slave: on-demand LiPo read (optional; slaves also push every ~30 s). */
+typedef struct _alox_EspNowBatteryQuery {
+    uint32_t client_id;
+} alox_EspNowBatteryQuery;
+
+/* * Slave → master: LiPo voltages (periodic ~30 s and on query). */
+typedef struct _alox_EspNowBatteryReport {
+    uint32_t client_id;
+    bool lipo1_valid;
+    bool lipo2_valid;
+    uint32_t lipo1_mv;
+    uint32_t lipo2_mv;
+} alox_EspNowBatteryReport;
+
 /* * Master → slave: LED ring command (same modes as UART LedRingProgressRequest). */
 typedef struct _alox_EspNowLedRing {
     uint32_t client_id;
@@ -132,6 +148,8 @@ typedef struct _alox_EspNowMessage {
         alox_EspNowAccelSample accel_sample;
         alox_EspNowAccelStream accel_stream;
         alox_EspNowLedRing led_ring;
+        alox_EspNowBatteryQuery battery_query;
+        alox_EspNowBatteryReport battery_report;
     } payload;
 } alox_EspNowMessage;
 
@@ -142,8 +160,10 @@ extern "C" {
 
 /* Helper constants for enums */
 #define _alox_EspNowMessageType_MIN alox_EspNowMessageType_ESPNOW_UNKNOWN
-#define _alox_EspNowMessageType_MAX alox_EspNowMessageType_ESPNOW_LED_RING
+#define _alox_EspNowMessageType_MAX alox_EspNowMessageType_ESPNOW_BATTERY_REPORT
-#define _alox_EspNowMessageType_ARRAYSIZE ((alox_EspNowMessageType)(alox_EspNowMessageType_ESPNOW_LED_RING+1))
+#define _alox_EspNowMessageType_ARRAYSIZE ((alox_EspNowMessageType)(alox_EspNowMessageType_ESPNOW_BATTERY_REPORT+1))
+
+
 
 
 
@@ -170,6 +190,8 @@ extern "C" {
 #define alox_EspNowAccelDeadzone_init_default    {0, 0}
 #define alox_EspNowAccelStream_init_default      {0, 0}
 #define alox_EspNowAccelSample_init_default      {0, 0, 0, 0}
+#define alox_EspNowBatteryQuery_init_default     {0}
+#define alox_EspNowBatteryReport_init_default    {0, 0, 0, 0, 0}
 #define alox_EspNowLedRing_init_default          {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
 #define alox_EspNowOtaStart_init_default         {0}
 #define alox_EspNowOtaPayload_init_default       {0, {0, {0}}}
@@ -184,6 +206,8 @@ extern "C" {
 #define alox_EspNowAccelDeadzone_init_zero       {0, 0}
 #define alox_EspNowAccelStream_init_zero         {0, 0}
 #define alox_EspNowAccelSample_init_zero         {0, 0, 0, 0}
+#define alox_EspNowBatteryQuery_init_zero        {0}
+#define alox_EspNowBatteryReport_init_zero       {0, 0, 0, 0, 0}
 #define alox_EspNowLedRing_init_zero             {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
 #define alox_EspNowOtaStart_init_zero            {0}
 #define alox_EspNowOtaPayload_init_zero          {0, {0, {0}}}
@@ -210,6 +234,12 @@ extern "C" {
 #define alox_EspNowAccelSample_x_tag             2
 #define alox_EspNowAccelSample_y_tag             3
 #define alox_EspNowAccelSample_z_tag             4
+#define alox_EspNowBatteryQuery_client_id_tag    1
+#define alox_EspNowBatteryReport_client_id_tag   1
+#define alox_EspNowBatteryReport_lipo1_valid_tag 2
+#define alox_EspNowBatteryReport_lipo2_valid_tag 3
+#define alox_EspNowBatteryReport_lipo1_mv_tag    4
+#define alox_EspNowBatteryReport_lipo2_mv_tag    5
 #define alox_EspNowLedRing_client_id_tag         1
 #define alox_EspNowLedRing_mode_tag              2
 #define alox_EspNowLedRing_progress_tag          3
@@ -241,6 +271,8 @@ extern "C" {
 #define alox_EspNowMessage_accel_sample_tag      13
 #define alox_EspNowMessage_accel_stream_tag      14
 #define alox_EspNowMessage_led_ring_tag          15
+#define alox_EspNowMessage_battery_query_tag     16
+#define alox_EspNowMessage_battery_report_tag    17
 
 /* Struct field encoding specification for nanopb */
 #define alox_EspNowUnicastTest_FIELDLIST(X, a) \
@@ -293,6 +325,20 @@ X(a, STATIC,   SINGULAR, SINT32,   z,                 4)
 #define alox_EspNowAccelSample_CALLBACK NULL
 #define alox_EspNowAccelSample_DEFAULT NULL
 
+#define alox_EspNowBatteryQuery_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UINT32,   client_id,         1)
+#define alox_EspNowBatteryQuery_CALLBACK NULL
+#define alox_EspNowBatteryQuery_DEFAULT NULL
+
+#define alox_EspNowBatteryReport_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UINT32,   client_id,         1) \
+X(a, STATIC,   SINGULAR, BOOL,     lipo1_valid,       2) \
+X(a, STATIC,   SINGULAR, BOOL,     lipo2_valid,       3) \
+X(a, STATIC,   SINGULAR, UINT32,   lipo1_mv,          4) \
+X(a, STATIC,   SINGULAR, UINT32,   lipo2_mv,          5)
+#define alox_EspNowBatteryReport_CALLBACK NULL
+#define alox_EspNowBatteryReport_DEFAULT NULL
+
 #define alox_EspNowLedRing_FIELDLIST(X, a) \
 X(a, STATIC,   SINGULAR, UINT32,   client_id,         1) \
 X(a, STATIC,   SINGULAR, UINT32,   mode,              2) \
@@ -345,7 +391,9 @@ X(a, STATIC,   ONEOF,    MESSAGE,  (payload,find_me,payload.find_me),  11) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,restart,payload.restart),  12) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_sample,payload.accel_sample),  13) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_stream,payload.accel_stream),  14) \
-X(a, STATIC,   ONEOF,    MESSAGE,  (payload,led_ring,payload.led_ring),  15)
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,led_ring,payload.led_ring),  15) \
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,battery_query,payload.battery_query),  16) \
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,battery_report,payload.battery_report),  17)
 #define alox_EspNowMessage_CALLBACK NULL
 #define alox_EspNowMessage_DEFAULT NULL
 #define alox_EspNowMessage_payload_discover_MSGTYPE alox_EspNowDiscover
@@ -362,6 +410,8 @@ X(a, STATIC,   ONEOF,    MESSAGE,  (payload,led_ring,payload.led_ring),  15)
 #define alox_EspNowMessage_payload_accel_sample_MSGTYPE alox_EspNowAccelSample
 #define alox_EspNowMessage_payload_accel_stream_MSGTYPE alox_EspNowAccelStream
 #define alox_EspNowMessage_payload_led_ring_MSGTYPE alox_EspNowLedRing
+#define alox_EspNowMessage_payload_battery_query_MSGTYPE alox_EspNowBatteryQuery
+#define alox_EspNowMessage_payload_battery_report_MSGTYPE alox_EspNowBatteryReport
 
 extern const pb_msgdesc_t alox_EspNowUnicastTest_msg;
 extern const pb_msgdesc_t alox_EspNowFindMe_msg;
@@ -371,6 +421,8 @@ extern const pb_msgdesc_t alox_EspNowSlavePresence_msg;
 extern const pb_msgdesc_t alox_EspNowAccelDeadzone_msg;
 extern const pb_msgdesc_t alox_EspNowAccelStream_msg;
 extern const pb_msgdesc_t alox_EspNowAccelSample_msg;
+extern const pb_msgdesc_t alox_EspNowBatteryQuery_msg;
+extern const pb_msgdesc_t alox_EspNowBatteryReport_msg;
 extern const pb_msgdesc_t alox_EspNowLedRing_msg;
 extern const pb_msgdesc_t alox_EspNowOtaStart_msg;
 extern const pb_msgdesc_t alox_EspNowOtaPayload_msg;
@@ -387,6 +439,8 @@ extern const pb_msgdesc_t alox_EspNowMessage_msg;
 #define alox_EspNowAccelDeadzone_fields &alox_EspNowAccelDeadzone_msg
 #define alox_EspNowAccelStream_fields &alox_EspNowAccelStream_msg
 #define alox_EspNowAccelSample_fields &alox_EspNowAccelSample_msg
+#define alox_EspNowBatteryQuery_fields &alox_EspNowBatteryQuery_msg
+#define alox_EspNowBatteryReport_fields &alox_EspNowBatteryReport_msg
 #define alox_EspNowLedRing_fields &alox_EspNowLedRing_msg
 #define alox_EspNowOtaStart_fields &alox_EspNowOtaStart_msg
 #define alox_EspNowOtaPayload_fields &alox_EspNowOtaPayload_msg
@@ -401,6 +455,8 @@ extern const pb_msgdesc_t alox_EspNowMessage_msg;
 #define alox_EspNowAccelDeadzone_size            12
 #define alox_EspNowAccelSample_size              24
 #define alox_EspNowAccelStream_size              8
+#define alox_EspNowBatteryQuery_size             6
+#define alox_EspNowBatteryReport_size            22
 #define alox_EspNowDiscover_size                 6
 #define alox_EspNowFindMe_size                   6
 #define alox_EspNowLedRing_size                  60

main/proto/esp_now_messages.proto

@@ -20,6 +20,8 @@ enum EspNowMessageType {
   ESPNOW_ACCEL_SAMPLE = 12;
   ESPNOW_SET_ACCEL_STREAM = 13;
   ESPNOW_LED_RING = 14;
+  ESPNOW_BATTERY_QUERY = 15;
+  ESPNOW_BATTERY_REPORT = 16;
 }
 
 message EspNowUnicastTest {
@@ -69,6 +71,20 @@ message EspNowAccelSample {
   sint32 z = 4;
 }
 
+/** Master → slave: on-demand LiPo read (optional; slaves also push every ~30 s). */
+message EspNowBatteryQuery {
+  uint32 client_id = 1;
+}
+
+/** Slave → master: LiPo voltages (periodic ~30 s and on query). */
+message EspNowBatteryReport {
+  uint32 client_id = 1;
+  bool lipo1_valid = 2;
+  bool lipo2_valid = 3;
+  uint32 lipo1_mv = 4;
+  uint32 lipo2_mv = 5;
+}
+
 /** Master → slave: LED ring command (same modes as UART LedRingProgressRequest). */
 message EspNowLedRing {
   uint32 client_id = 1;
@@ -121,5 +137,7 @@ message EspNowMessage {
     EspNowAccelSample accel_sample = 13;
     EspNowAccelStream accel_stream = 14;
     EspNowLedRing led_ring = 15;
+    EspNowBatteryQuery battery_query = 16;
+    EspNowBatteryReport battery_report = 17;
   }
 }

main/proto/uart_messages.pb.c

@@ -42,6 +42,18 @@ PB_BIND(alox_AccelStreamRequest, alox_AccelStreamRequest, AUTO)
 PB_BIND(alox_AccelStreamResponse, alox_AccelStreamResponse, AUTO)
 
 
+PB_BIND(alox_BatteryStatusRequest, alox_BatteryStatusRequest, AUTO)
+
+
+PB_BIND(alox_LipoReading, alox_LipoReading, AUTO)
+
+
+PB_BIND(alox_BatterySample, alox_BatterySample, AUTO)
+
+
+PB_BIND(alox_BatteryStatusResponse, alox_BatteryStatusResponse, 2)
+
+
 PB_BIND(alox_AccelSnapshotRequest, alox_AccelSnapshotRequest, AUTO)
 
 

main/proto/uart_messages.pb.h

@@ -29,7 +29,8 @@ typedef enum _alox_MessageType {
     alox_MessageType_FIND_ME = 22,
     alox_MessageType_RESTART = 23,
     alox_MessageType_ACCEL_SNAPSHOT = 24,
-    alox_MessageType_ACCEL_STREAM = 25
+    alox_MessageType_ACCEL_STREAM = 25,
+    alox_MessageType_BATTERY_STATUS = 26
 } alox_MessageType;
 
 /* Struct definitions */
@@ -108,6 +109,36 @@ typedef struct _alox_AccelStreamResponse {
     uint32_t slaves_updated;
 } alox_AccelStreamResponse;
 
+/* * Host → master: read LiPo ADC voltages (master local and/or slaves via ESP-NOW). */
+typedef struct _alox_BatteryStatusRequest {
+    /* * 0 = master only; >0 = one slave; ignored when all_clients */
+    uint32_t client_id;
+    /* * Master (client_id 0) plus every registered slave */
+    bool all_clients;
+} alox_BatteryStatusRequest;
+
+typedef struct _alox_LipoReading {
+    bool valid;
+    /* * Estimated pack voltage in millivolts from ADC */
+    uint32_t voltage_mv;
+} alox_LipoReading;
+
+typedef struct _alox_BatterySample {
+    uint32_t client_id;
+    bool has_lipo1;
+    alox_LipoReading lipo1;
+    bool has_lipo2;
+    alox_LipoReading lipo2;
+    /* * Milliseconds since last ESP-NOW battery report from this pod. */
+    uint32_t age_ms;
+} alox_BatterySample;
+
+typedef struct _alox_BatteryStatusResponse {
+    bool success;
+    pb_size_t samples_count;
+    alox_BatterySample samples[17];
+} alox_BatteryStatusResponse;
+
 /* Host → master: read cached accel samples from slaves (only while stream enabled).
  client_id 0 = all registered slaves; otherwise one slave. */
 typedef struct _alox_AccelSnapshotRequest {
@@ -271,6 +302,8 @@ typedef struct _alox_UartMessage {
         alox_AccelSnapshotResponse accel_snapshot_response;
         alox_AccelStreamRequest accel_stream_request;
         alox_AccelStreamResponse accel_stream_response;
+        alox_BatteryStatusRequest battery_status_request;
+        alox_BatteryStatusResponse battery_status_response;
     } payload;
 } alox_UartMessage;
 
@@ -281,8 +314,8 @@ extern "C" {
 
 /* Helper constants for enums */
 #define _alox_MessageType_MIN alox_MessageType_UNKNOWN
-#define _alox_MessageType_MAX alox_MessageType_ACCEL_STREAM
+#define _alox_MessageType_MAX alox_MessageType_BATTERY_STATUS
-#define _alox_MessageType_ARRAYSIZE ((alox_MessageType)(alox_MessageType_ACCEL_STREAM+1))
+#define _alox_MessageType_ARRAYSIZE ((alox_MessageType)(alox_MessageType_BATTERY_STATUS+1))
 
 #define alox_UartMessage_type_ENUMTYPE alox_MessageType
 
@@ -311,6 +344,10 @@ extern "C" {
 
 
 
+
+
+
+
 
 
 
@@ -329,6 +366,10 @@ extern "C" {
 #define alox_AccelDeadzoneResponse_init_default  {0, 0, 0, 0}
 #define alox_AccelStreamRequest_init_default     {0, 0, 0, 0}
 #define alox_AccelStreamResponse_init_default    {0, 0, 0, 0}
+#define alox_BatteryStatusRequest_init_default   {0, 0}
+#define alox_LipoReading_init_default            {0, 0}
+#define alox_BatterySample_init_default          {0, false, alox_LipoReading_init_default, false, alox_LipoReading_init_default, 0}
+#define alox_BatteryStatusResponse_init_default  {0, 0, {alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default, alox_BatterySample_init_default}}
 #define alox_AccelSnapshotRequest_init_default   {0}
 #define alox_AccelSample_init_default            {0, 0, 0, 0, 0, 0}
 #define alox_AccelSnapshotResponse_init_default  {0, {alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default, alox_AccelSample_init_default}}
@@ -359,6 +400,10 @@ extern "C" {
 #define alox_AccelDeadzoneResponse_init_zero     {0, 0, 0, 0}
 #define alox_AccelStreamRequest_init_zero        {0, 0, 0, 0}
 #define alox_AccelStreamResponse_init_zero       {0, 0, 0, 0}
+#define alox_BatteryStatusRequest_init_zero      {0, 0}
+#define alox_LipoReading_init_zero               {0, 0}
+#define alox_BatterySample_init_zero             {0, false, alox_LipoReading_init_zero, false, alox_LipoReading_init_zero, 0}
+#define alox_BatteryStatusResponse_init_zero     {0, 0, {alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero, alox_BatterySample_init_zero}}
 #define alox_AccelSnapshotRequest_init_zero      {0}
 #define alox_AccelSample_init_zero               {0, 0, 0, 0, 0, 0}
 #define alox_AccelSnapshotResponse_init_zero     {0, {alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero, alox_AccelSample_init_zero}}
@@ -413,6 +458,16 @@ extern "C" {
 #define alox_AccelStreamResponse_client_id_tag   2
 #define alox_AccelStreamResponse_success_tag     3
 #define alox_AccelStreamResponse_slaves_updated_tag 4
+#define alox_BatteryStatusRequest_client_id_tag  1
+#define alox_BatteryStatusRequest_all_clients_tag 2
+#define alox_LipoReading_valid_tag               1
+#define alox_LipoReading_voltage_mv_tag          2
+#define alox_BatterySample_client_id_tag         1
+#define alox_BatterySample_lipo1_tag             2
+#define alox_BatterySample_lipo2_tag             3
+#define alox_BatterySample_age_ms_tag            4
+#define alox_BatteryStatusResponse_success_tag   1
+#define alox_BatteryStatusResponse_samples_tag   2
 #define alox_AccelSnapshotRequest_client_id_tag  1
 #define alox_AccelSample_client_id_tag           1
 #define alox_AccelSample_valid_tag               2
@@ -493,6 +548,8 @@ extern "C" {
 #define alox_UartMessage_accel_snapshot_response_tag 24
 #define alox_UartMessage_accel_stream_request_tag 25
 #define alox_UartMessage_accel_stream_response_tag 26
+#define alox_UartMessage_battery_status_request_tag 27
+#define alox_UartMessage_battery_status_response_tag 28
 
 /* Struct field encoding specification for nanopb */
 #define alox_UartMessage_FIELDLIST(X, a) \
@@ -521,7 +578,9 @@ X(a, STATIC,   ONEOF,    MESSAGE,  (payload,restart_response,payload.restart_res
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_snapshot_request,payload.accel_snapshot_request),  23) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_snapshot_response,payload.accel_snapshot_response),  24) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_stream_request,payload.accel_stream_request),  25) \
-X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_stream_response,payload.accel_stream_response),  26)
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_stream_response,payload.accel_stream_response),  26) \
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,battery_status_request,payload.battery_status_request),  27) \
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,battery_status_response,payload.battery_status_response),  28)
 #define alox_UartMessage_CALLBACK NULL
 #define alox_UartMessage_DEFAULT NULL
 #define alox_UartMessage_payload_ack_payload_MSGTYPE alox_Ack
@@ -549,6 +608,8 @@ X(a, STATIC,   ONEOF,    MESSAGE,  (payload,accel_stream_response,payload.accel_
 #define alox_UartMessage_payload_accel_snapshot_response_MSGTYPE alox_AccelSnapshotResponse
 #define alox_UartMessage_payload_accel_stream_request_MSGTYPE alox_AccelStreamRequest
 #define alox_UartMessage_payload_accel_stream_response_MSGTYPE alox_AccelStreamResponse
+#define alox_UartMessage_payload_battery_status_request_MSGTYPE alox_BatteryStatusRequest
+#define alox_UartMessage_payload_battery_status_response_MSGTYPE alox_BatteryStatusResponse
 
 #define alox_Ack_FIELDLIST(X, a) \
 
@@ -631,6 +692,35 @@ X(a, STATIC,   SINGULAR, UINT32,   slaves_updated,    4)
 #define alox_AccelStreamResponse_CALLBACK NULL
 #define alox_AccelStreamResponse_DEFAULT NULL
 
+#define alox_BatteryStatusRequest_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UINT32,   client_id,         1) \
+X(a, STATIC,   SINGULAR, BOOL,     all_clients,       2)
+#define alox_BatteryStatusRequest_CALLBACK NULL
+#define alox_BatteryStatusRequest_DEFAULT NULL
+
+#define alox_LipoReading_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, BOOL,     valid,             1) \
+X(a, STATIC,   SINGULAR, UINT32,   voltage_mv,        2)
+#define alox_LipoReading_CALLBACK NULL
+#define alox_LipoReading_DEFAULT NULL
+
+#define alox_BatterySample_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UINT32,   client_id,         1) \
+X(a, STATIC,   OPTIONAL, MESSAGE,  lipo1,             2) \
+X(a, STATIC,   OPTIONAL, MESSAGE,  lipo2,             3) \
+X(a, STATIC,   SINGULAR, UINT32,   age_ms,            4)
+#define alox_BatterySample_CALLBACK NULL
+#define alox_BatterySample_DEFAULT NULL
+#define alox_BatterySample_lipo1_MSGTYPE alox_LipoReading
+#define alox_BatterySample_lipo2_MSGTYPE alox_LipoReading
+
+#define alox_BatteryStatusResponse_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, BOOL,     success,           1) \
+X(a, STATIC,   REPEATED, MESSAGE,  samples,           2)
+#define alox_BatteryStatusResponse_CALLBACK NULL
+#define alox_BatteryStatusResponse_DEFAULT NULL
+#define alox_BatteryStatusResponse_samples_MSGTYPE alox_BatterySample
+
 #define alox_AccelSnapshotRequest_FIELDLIST(X, a) \
 X(a, STATIC,   SINGULAR, UINT32,   client_id,         1)
 #define alox_AccelSnapshotRequest_CALLBACK NULL
@@ -772,6 +862,10 @@ extern const pb_msgdesc_t alox_AccelDeadzoneRequest_msg;
 extern const pb_msgdesc_t alox_AccelDeadzoneResponse_msg;
 extern const pb_msgdesc_t alox_AccelStreamRequest_msg;
 extern const pb_msgdesc_t alox_AccelStreamResponse_msg;
+extern const pb_msgdesc_t alox_BatteryStatusRequest_msg;
+extern const pb_msgdesc_t alox_LipoReading_msg;
+extern const pb_msgdesc_t alox_BatterySample_msg;
+extern const pb_msgdesc_t alox_BatteryStatusResponse_msg;
 extern const pb_msgdesc_t alox_AccelSnapshotRequest_msg;
 extern const pb_msgdesc_t alox_AccelSample_msg;
 extern const pb_msgdesc_t alox_AccelSnapshotResponse_msg;
@@ -804,6 +898,10 @@ extern const pb_msgdesc_t alox_OtaSlaveProgressResponse_msg;
 #define alox_AccelDeadzoneResponse_fields &alox_AccelDeadzoneResponse_msg
 #define alox_AccelStreamRequest_fields &alox_AccelStreamRequest_msg
 #define alox_AccelStreamResponse_fields &alox_AccelStreamResponse_msg
+#define alox_BatteryStatusRequest_fields &alox_BatteryStatusRequest_msg
+#define alox_LipoReading_fields &alox_LipoReading_msg
+#define alox_BatterySample_fields &alox_BatterySample_msg
+#define alox_BatteryStatusResponse_fields &alox_BatteryStatusResponse_msg
 #define alox_AccelSnapshotRequest_fields &alox_AccelSnapshotRequest_msg
 #define alox_AccelSample_fields &alox_AccelSample_msg
 #define alox_AccelSnapshotResponse_fields &alox_AccelSnapshotResponse_msg
@@ -830,7 +928,7 @@ extern const pb_msgdesc_t alox_OtaSlaveProgressResponse_msg;
 /* alox_ClientInfo_size depends on runtime parameters */
 /* alox_ClientInfoResponse_size depends on runtime parameters */
 /* alox_ClientInputResponse_size depends on runtime parameters */
-#define ALOX_UART_MESSAGES_PB_H_MAX_SIZE         alox_AccelSnapshotResponse_size
+#define ALOX_UART_MESSAGES_PB_H_MAX_SIZE         alox_BatteryStatusResponse_size
 #define alox_AccelDeadzoneRequest_size           16
 #define alox_AccelDeadzoneResponse_size          20
 #define alox_AccelSample_size                    32
@@ -839,6 +937,9 @@ extern const pb_msgdesc_t alox_OtaSlaveProgressResponse_msg;
 #define alox_AccelStreamRequest_size             12
 #define alox_AccelStreamResponse_size            16
 #define alox_Ack_size                            0
+#define alox_BatterySample_size                  32
+#define alox_BatteryStatusRequest_size           8
+#define alox_BatteryStatusResponse_size          580
 #define alox_ClientInput_size                    22
 #define alox_EspNowFindMeRequest_size            6
 #define alox_EspNowFindMeResponse_size           8
@@ -846,6 +947,7 @@ extern const pb_msgdesc_t alox_OtaSlaveProgressResponse_msg;
 #define alox_EspNowUnicastTestResponse_size      8
 #define alox_LedRingProgressRequest_size         64
 #define alox_LedRingProgressResponse_size        32
+#define alox_LipoReading_size                    8
 #define alox_OtaEndPayload_size                  0
 #define alox_OtaPayload_size                     209
 #define alox_OtaSlaveProgressEntry_size          30

main/proto/uart_messages.proto

@@ -24,6 +24,7 @@ enum MessageType {
   RESTART = 23;
   ACCEL_SNAPSHOT = 24;
   ACCEL_STREAM = 25;
+  BATTERY_STATUS = 26;
 }
 
 message UartMessage {
@@ -54,6 +55,8 @@ message UartMessage {
     AccelSnapshotResponse accel_snapshot_response = 24;
     AccelStreamRequest accel_stream_request = 25;
     AccelStreamResponse accel_stream_response = 26;
+    BatteryStatusRequest battery_status_request = 27;
+    BatteryStatusResponse battery_status_response = 28;
   }
 }
 
@@ -130,6 +133,33 @@ message AccelStreamResponse {
   uint32 slaves_updated = 4;
 }
 
+/** Host → master: read LiPo ADC voltages (master local and/or slaves via ESP-NOW). */
+message BatteryStatusRequest {
+  /** 0 = master only; >0 = one slave; ignored when all_clients */
+  uint32 client_id = 1;
+  /** Master (client_id 0) plus every registered slave */
+  bool all_clients = 2;
+}
+
+message LipoReading {
+  bool valid = 1;
+  /** Estimated pack voltage in millivolts from ADC */
+  uint32 voltage_mv = 2;
+}
+
+message BatterySample {
+  uint32 client_id = 1;
+  LipoReading lipo1 = 2;
+  LipoReading lipo2 = 3;
+  /** Milliseconds since last ESP-NOW battery report from this pod. */
+  uint32 age_ms = 4;
+}
+
+message BatteryStatusResponse {
+  bool success = 1;
+  repeated BatterySample samples = 2 [(nanopb).max_count = 17];
+}
+
 // Host → master: read cached accel samples from slaves (only while stream enabled).
 // client_id 0 = all registered slaves; otherwise one slave.
 message AccelSnapshotRequest {