Add CACHE_STATUS UART poll and dashboard live stream.

Combine cached accel and tap in one low-overhead master command for ~16 ms
host polling. The dashboard uses a single live-stream toggle plus per-slave
accel-stream controls; fix live_stream state so polling is not cleared every
slow client refresh.

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

main/CMakeLists.txt

@@ -22,6 +22,7 @@ idf_component_register(
   "cmd/cmd_accel_stream.c"
   "cmd/cmd_tap_notify.c"
   "cmd/cmd_tap_snapshot.c"
+  "cmd/cmd_cache_status.c"
   "cmd/cmd_espnow_unicast_test.c"
   "cmd/cmd_espnow_find_me.c"
   "cmd/cmd_restart.c"

main/README.md

@@ -225,6 +225,7 @@ Host and master speak nanopb-encoded `UartMessage` inside UART frames (byte 0 =
 | 24 | `ACCEL_SNAPSHOT` | Implemented (`cmd/cmd_accel_snapshot.c`) — cached slave accel from ESP-NOW stream |
 | 27 | `TAP_NOTIFY` | Implemented (`cmd/cmd_tap_notify.c`) — get/set which tap kinds notify via ESP-NOW |
 | 28 | `TAP_SNAPSHOT` | Implemented (`cmd/cmd_tap_snapshot.c`) — consume cached tap events from master registry |
+| 29 | `CACHE_STATUS` | Implemented (`cmd/cmd_cache_status.c`) — combined accel + tap cache in one UART round-trip |
 
 Regenerate C code:
 
@@ -367,6 +368,17 @@ go run . -port /dev/ttyUSB0 tap-notify -client 16
 
 Read **cached** tap events on the **master** (one pending event per slave). Slaves send `ESPNOW_TAP_EVENT` on tap; the master stores the latest value per client in `client_registry.c` for up to **16 ms** (`CLIENT_REGISTRY_TAP_MAX_AGE_MS`). Each snapshot **consumes** fresh events (cleared after read).
 
+### CACHE_STATUS command
+
+Fast combined poll for host tools at **16 ms** or faster: one UART frame, no request body (command id `0x1d` only).
+
+**Response:** `cache_status_response` with:
+
+- `accel[]` — same as `ACCEL_SNAPSHOT`, only clients with `accel_stream_enabled`
+- `taps[]` — same as `TAP_SNAPSHOT`, only clients with any tap notify flag; pending taps are consumed
+
+The master walks `client_registry` once per request (`cmd/cmd_cache_status.c`). Prefer this over separate `ACCEL_SNAPSHOT` + `TAP_SNAPSHOT` when polling both streams.
+
 Only slaves with at least one tap-notify flag enabled are included.
 
 **Request:** framed `1c` (`0x1c`) + optional `tap_snapshot_request` (`client_id`: `0` = all, `>0` = one id).
@@ -555,6 +567,7 @@ Target: ESP32-S3. Close serial monitor on the UART adapter port before running `
 | `cmd/cmd_accel_snapshot.c` | UART `ACCEL_SNAPSHOT` — cached slave accel |
 | `cmd/cmd_tap_notify.c` | UART `TAP_NOTIFY` — ESP-NOW tap notify config |
 | `cmd/cmd_tap_snapshot.c` | UART `TAP_SNAPSHOT` — consume cached tap events |
+| `cmd/cmd_cache_status.c` | UART `CACHE_STATUS` — combined accel + tap cache poll |
 | `board_input.c/h` | Taster GPIO12, LiPo ADC on GPIO1 / GPIO12 |
 | `pod_settings.c/h` | NVS persistence (accel deadzone, …) |
 | `led_ring.c/h` | LED ring (digit display, progress bar) |

main/cmd/cmd_cache_status.c

@@ -0,0 +1,83 @@
+#include "client_registry.h"
+#include "cmd_cache_status.h"
+#include "uart_cmd.h"
+
+static const char *TAG = "[CACHE_STAT]";
+
+static bool tap_notify_any(const client_info_t *client) {
+  return client != NULL &&
+         (client->tap_notify_single || client->tap_notify_double ||
+          client->tap_notify_triple);
+}
+
+static alox_TapKind tap_kind_from_registry(uint32_t kind) {
+  switch (kind) {
+  case 1:
+    return alox_TapKind_TAP_SINGLE;
+  case 2:
+    return alox_TapKind_TAP_DOUBLE;
+  case 3:
+    return alox_TapKind_TAP_TRIPLE;
+  default:
+    return alox_TapKind_TAP_NONE;
+  }
+}
+
+static void fill_cache_status(alox_CacheStatusResponse *out) {
+  if (out == NULL) {
+    return;
+  }
+
+  out->accel_count = 0;
+  out->taps_count = 0;
+
+  size_t count = client_registry_count();
+  for (size_t i = 0; i < count; i++) {
+    const client_info_t *client = client_registry_at(i);
+    if (client == NULL) {
+      continue;
+    }
+
+    if (client->accel_stream_enabled &&
+        out->accel_count < sizeof(out->accel) / sizeof(out->accel[0])) {
+      alox_AccelSample *sample = &out->accel[out->accel_count++];
+      sample->client_id = client->id;
+      sample->valid = client->accel_valid;
+      sample->x = client->accel_x;
+      sample->y = client->accel_y;
+      sample->z = client->accel_z;
+      if (client->accel_valid) {
+        sample->age_ms = client_registry_ms_since(client->accel_updated_at);
+      }
+    }
+
+    if (tap_notify_any(client) &&
+        out->taps_count < sizeof(out->taps) / sizeof(out->taps[0])) {
+      uint32_t kind = 0;
+      uint32_t age_ms = 0;
+      if (!client_registry_take_tap(client->id, &kind, &age_ms)) {
+        continue;
+      }
+      alox_TapEvent *event = &out->taps[out->taps_count++];
+      event->client_id = client->id;
+      event->valid = true;
+      event->kind = tap_kind_from_registry(kind);
+      event->age_ms = age_ms;
+    }
+  }
+}
+
+static void handle_cache_status(const uint8_t *data, size_t len) {
+  (void)data;
+  (void)len;
+
+  alox_UartMessage response;
+  uart_cmd_init_response(&response, alox_MessageType_CACHE_STATUS,
+                         alox_UartMessage_cache_status_response_tag);
+  fill_cache_status(&response.payload.cache_status_response);
+  uart_cmd_send(&response, TAG);
+}
+
+void cmd_cache_status_register(void) {
+  uart_cmd_register(alox_MessageType_CACHE_STATUS, handle_cache_status);
+}

main/cmd/cmd_cache_status.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void cmd_cache_status_register(void);

main/cmd/cmd_handler.c

@@ -58,6 +58,8 @@ static const char *message_type_name(uint16_t id) {
     return "TAP_NOTIFY";
   case alox_MessageType_TAP_SNAPSHOT:
     return "TAP_SNAPSHOT";
+  case alox_MessageType_CACHE_STATUS:
+    return "CACHE_STATUS";
   default:
     return "UNKNOWN";
   }

main/powerpod.c

@@ -5,6 +5,7 @@
 #include "cmd_accel_stream.h"
 #include "cmd_tap_notify.h"
 #include "cmd_tap_snapshot.h"
+#include "cmd_cache_status.h"
 #include "cmd_espnow_unicast_test.h"
 #include "cmd_espnow_find_me.h"
 #include "cmd_restart.h"
@@ -186,6 +187,7 @@ void app_main(void) {
     cmd_accel_stream_register();
     cmd_tap_notify_register();
     cmd_tap_snapshot_register();
+    cmd_cache_status_register();
     cmd_espnow_unicast_test_register();
     cmd_espnow_find_me_register();
     cmd_restart_register();

main/proto/uart_messages.pb.c

@@ -78,6 +78,12 @@ PB_BIND(alox_TapEvent, alox_TapEvent, AUTO)
 PB_BIND(alox_TapSnapshotResponse, alox_TapSnapshotResponse, 2)
 
 
+PB_BIND(alox_CacheStatusRequest, alox_CacheStatusRequest, AUTO)
+
+
+PB_BIND(alox_CacheStatusResponse, alox_CacheStatusResponse, 2)
+
+
 PB_BIND(alox_EspNowUnicastTestRequest, alox_EspNowUnicastTestRequest, AUTO)
 
 

main/proto/uart_messages.pb.h

@@ -32,7 +32,9 @@ typedef enum _alox_MessageType {
     alox_MessageType_ACCEL_STREAM = 25,
     alox_MessageType_BATTERY_STATUS = 26,
     alox_MessageType_TAP_NOTIFY = 27,
-    alox_MessageType_TAP_SNAPSHOT = 28
+    alox_MessageType_TAP_SNAPSHOT = 28,
+    /* * Combined cached accel + tap poll (one UART round-trip, ~16 ms cadence). */
+    alox_MessageType_CACHE_STATUS = 29
 } alox_MessageType;
 
 typedef enum _alox_TapKind {
@@ -209,6 +211,20 @@ typedef struct _alox_TapSnapshotResponse {
     alox_TapEvent events[16];
 } alox_TapSnapshotResponse;
 
+/* * Host → master: one-shot read of subscribed cached slave data (no request body). */
+typedef struct _alox_CacheStatusRequest {
+    char dummy_field;
+} alox_CacheStatusRequest;
+
+typedef struct _alox_CacheStatusResponse {
+    /* * Slaves with accel_stream_enabled. */
+    pb_size_t accel_count;
+    alox_AccelSample accel[16];
+    /* * Slaves with any tap notify flag; pending taps are consumed (like TAP_SNAPSHOT). */
+    pb_size_t taps_count;
+    alox_TapEvent taps[16];
+} alox_CacheStatusResponse;
+
 typedef struct _alox_EspNowUnicastTestRequest {
     uint32_t client_id;
     uint32_t seq;
@@ -357,6 +373,8 @@ typedef struct _alox_UartMessage {
         alox_TapNotifyResponse tap_notify_response;
         alox_TapSnapshotRequest tap_snapshot_request;
         alox_TapSnapshotResponse tap_snapshot_response;
+        alox_CacheStatusRequest cache_status_request;
+        alox_CacheStatusResponse cache_status_response;
     } payload;
 } alox_UartMessage;
 
@@ -367,8 +385,8 @@ extern "C" {
 
 /* Helper constants for enums */
 #define _alox_MessageType_MIN alox_MessageType_UNKNOWN
-#define _alox_MessageType_MAX alox_MessageType_TAP_SNAPSHOT
-#define _alox_MessageType_ARRAYSIZE ((alox_MessageType)(alox_MessageType_TAP_SNAPSHOT+1))
+#define _alox_MessageType_MAX alox_MessageType_CACHE_STATUS
+#define _alox_MessageType_ARRAYSIZE ((alox_MessageType)(alox_MessageType_CACHE_STATUS+1))
 
 #define _alox_TapKind_MIN alox_TapKind_TAP_NONE
 #define _alox_TapKind_MAX alox_TapKind_TAP_TRIPLE
@@ -416,6 +434,8 @@ extern "C" {
 
 
 
+
+
 /* Initializer values for message structs */
 #define alox_UartMessage_init_default            {_alox_MessageType_MIN, 0, {alox_Ack_init_default}}
 #define alox_Ack_init_default                    {0}
@@ -441,6 +461,8 @@ extern "C" {
 #define alox_TapSnapshotRequest_init_default     {0}
 #define alox_TapEvent_init_default               {0, 0, _alox_TapKind_MIN, 0}
 #define alox_TapSnapshotResponse_init_default    {0, {alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default}}
+#define alox_CacheStatusRequest_init_default     {0}
+#define alox_CacheStatusResponse_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}, 0, {alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default, alox_TapEvent_init_default}}
 #define alox_EspNowUnicastTestRequest_init_default {0, 0}
 #define alox_EspNowUnicastTestResponse_init_default {0, 0}
 #define alox_LedRingProgressRequest_init_default {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
@@ -480,6 +502,8 @@ extern "C" {
 #define alox_TapSnapshotRequest_init_zero        {0}
 #define alox_TapEvent_init_zero                  {0, 0, _alox_TapKind_MIN, 0}
 #define alox_TapSnapshotResponse_init_zero       {0, {alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero}}
+#define alox_CacheStatusRequest_init_zero        {0}
+#define alox_CacheStatusResponse_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}, 0, {alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero, alox_TapEvent_init_zero}}
 #define alox_EspNowUnicastTestRequest_init_zero  {0, 0}
 #define alox_EspNowUnicastTestResponse_init_zero {0, 0}
 #define alox_LedRingProgressRequest_init_zero    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
@@ -570,6 +594,8 @@ extern "C" {
 #define alox_TapEvent_kind_tag                   3
 #define alox_TapEvent_age_ms_tag                 4
 #define alox_TapSnapshotResponse_events_tag      1
+#define alox_CacheStatusResponse_accel_tag       1
+#define alox_CacheStatusResponse_taps_tag        2
 #define alox_EspNowUnicastTestRequest_client_id_tag 1
 #define alox_EspNowUnicastTestRequest_seq_tag    2
 #define alox_EspNowUnicastTestResponse_success_tag 1
@@ -648,6 +674,8 @@ extern "C" {
 #define alox_UartMessage_tap_notify_response_tag 30
 #define alox_UartMessage_tap_snapshot_request_tag 31
 #define alox_UartMessage_tap_snapshot_response_tag 32
+#define alox_UartMessage_cache_status_request_tag 33
+#define alox_UartMessage_cache_status_response_tag 34
 
 /* Struct field encoding specification for nanopb */
 #define alox_UartMessage_FIELDLIST(X, a) \
@@ -682,7 +710,9 @@ X(a, STATIC,   ONEOF,    MESSAGE,  (payload,battery_status_response,payload.batt
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,tap_notify_request,payload.tap_notify_request),  29) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,tap_notify_response,payload.tap_notify_response),  30) \
 X(a, STATIC,   ONEOF,    MESSAGE,  (payload,tap_snapshot_request,payload.tap_snapshot_request),  31) \
-X(a, STATIC,   ONEOF,    MESSAGE,  (payload,tap_snapshot_response,payload.tap_snapshot_response),  32)
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,tap_snapshot_response,payload.tap_snapshot_response),  32) \
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,cache_status_request,payload.cache_status_request),  33) \
+X(a, STATIC,   ONEOF,    MESSAGE,  (payload,cache_status_response,payload.cache_status_response),  34)
 #define alox_UartMessage_CALLBACK NULL
 #define alox_UartMessage_DEFAULT NULL
 #define alox_UartMessage_payload_ack_payload_MSGTYPE alox_Ack
@@ -716,6 +746,8 @@ X(a, STATIC,   ONEOF,    MESSAGE,  (payload,tap_snapshot_response,payload.tap_sn
 #define alox_UartMessage_payload_tap_notify_response_MSGTYPE alox_TapNotifyResponse
 #define alox_UartMessage_payload_tap_snapshot_request_MSGTYPE alox_TapSnapshotRequest
 #define alox_UartMessage_payload_tap_snapshot_response_MSGTYPE alox_TapSnapshotResponse
+#define alox_UartMessage_payload_cache_status_request_MSGTYPE alox_CacheStatusRequest
+#define alox_UartMessage_payload_cache_status_response_MSGTYPE alox_CacheStatusResponse
 
 #define alox_Ack_FIELDLIST(X, a) \
 
@@ -890,6 +922,19 @@ X(a, STATIC,   REPEATED, MESSAGE,  events,            1)
 #define alox_TapSnapshotResponse_DEFAULT NULL
 #define alox_TapSnapshotResponse_events_MSGTYPE alox_TapEvent
 
+#define alox_CacheStatusRequest_FIELDLIST(X, a) \
+
+#define alox_CacheStatusRequest_CALLBACK NULL
+#define alox_CacheStatusRequest_DEFAULT NULL
+
+#define alox_CacheStatusResponse_FIELDLIST(X, a) \
+X(a, STATIC,   REPEATED, MESSAGE,  accel,             1) \
+X(a, STATIC,   REPEATED, MESSAGE,  taps,              2)
+#define alox_CacheStatusResponse_CALLBACK NULL
+#define alox_CacheStatusResponse_DEFAULT NULL
+#define alox_CacheStatusResponse_accel_MSGTYPE alox_AccelSample
+#define alox_CacheStatusResponse_taps_MSGTYPE alox_TapEvent
+
 #define alox_EspNowUnicastTestRequest_FIELDLIST(X, a) \
 X(a, STATIC,   SINGULAR, UINT32,   client_id,         1) \
 X(a, STATIC,   SINGULAR, UINT32,   seq,               2)
@@ -1022,6 +1067,8 @@ extern const pb_msgdesc_t alox_TapNotifyResponse_msg;
 extern const pb_msgdesc_t alox_TapSnapshotRequest_msg;
 extern const pb_msgdesc_t alox_TapEvent_msg;
 extern const pb_msgdesc_t alox_TapSnapshotResponse_msg;
+extern const pb_msgdesc_t alox_CacheStatusRequest_msg;
+extern const pb_msgdesc_t alox_CacheStatusResponse_msg;
 extern const pb_msgdesc_t alox_EspNowUnicastTestRequest_msg;
 extern const pb_msgdesc_t alox_EspNowUnicastTestResponse_msg;
 extern const pb_msgdesc_t alox_LedRingProgressRequest_msg;
@@ -1063,6 +1110,8 @@ extern const pb_msgdesc_t alox_OtaSlaveProgressResponse_msg;
 #define alox_TapSnapshotRequest_fields &alox_TapSnapshotRequest_msg
 #define alox_TapEvent_fields &alox_TapEvent_msg
 #define alox_TapSnapshotResponse_fields &alox_TapSnapshotResponse_msg
+#define alox_CacheStatusRequest_fields &alox_CacheStatusRequest_msg
+#define alox_CacheStatusResponse_fields &alox_CacheStatusResponse_msg
 #define alox_EspNowUnicastTestRequest_fields &alox_EspNowUnicastTestRequest_msg
 #define alox_EspNowUnicastTestResponse_fields &alox_EspNowUnicastTestResponse_msg
 #define alox_LedRingProgressRequest_fields &alox_LedRingProgressRequest_msg
@@ -1086,7 +1135,7 @@ 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_BatteryStatusResponse_size
+#define ALOX_UART_MESSAGES_PB_H_MAX_SIZE         alox_CacheStatusResponse_size
 #define alox_AccelDeadzoneRequest_size           16
 #define alox_AccelDeadzoneResponse_size          20
 #define alox_AccelSample_size                    32
@@ -1098,6 +1147,8 @@ extern const pb_msgdesc_t alox_OtaSlaveProgressResponse_msg;
 #define alox_BatterySample_size                  32
 #define alox_BatteryStatusRequest_size           8
 #define alox_BatteryStatusResponse_size          580
+#define alox_CacheStatusRequest_size             0
+#define alox_CacheStatusResponse_size            832
 #define alox_ClientInput_size                    22
 #define alox_EspNowFindMeRequest_size            6
 #define alox_EspNowFindMeResponse_size           8

main/proto/uart_messages.proto

@@ -27,6 +27,8 @@ enum MessageType {
   BATTERY_STATUS = 26;
   TAP_NOTIFY = 27;
   TAP_SNAPSHOT = 28;
+  /** Combined cached accel + tap poll (one UART round-trip, ~16 ms cadence). */
+  CACHE_STATUS = 29;
 }
 
 message UartMessage {
@@ -63,6 +65,8 @@ message UartMessage {
     TapNotifyResponse tap_notify_response = 30;
     TapSnapshotRequest tap_snapshot_request = 31;
     TapSnapshotResponse tap_snapshot_response = 32;
+    CacheStatusRequest cache_status_request = 33;
+    CacheStatusResponse cache_status_response = 34;
   }
 }
 
@@ -232,6 +236,16 @@ message TapSnapshotResponse {
   repeated TapEvent events = 1 [(nanopb).max_count = 16];
 }
 
+/** Host → master: one-shot read of subscribed cached slave data (no request body). */
+message CacheStatusRequest {}
+
+message CacheStatusResponse {
+  /** Slaves with accel_stream_enabled. */
+  repeated AccelSample accel = 1 [(nanopb).max_count = 16];
+  /** Slaves with any tap notify flag; pending taps are consumed (like TAP_SNAPSHOT). */
+  repeated TapEvent taps = 2 [(nanopb).max_count = 16];
+}
+
 message EspNowUnicastTestRequest {
   uint32 client_id = 1;
   uint32 seq = 2;