Added ECHO cmd and fixed some timing issues

main/esp_now_slave.c

@@ -21,6 +21,8 @@
 
 #define ESPNOW_HEARTBEAT_INTERVAL_MS 1000
 #define SLAVE_MASTER_LOST_MS (ESPNOW_HEARTBEAT_INTERVAL_MS * 5)
+/** While master or slave OTA is in progress (discover may be sparse). */
+#define SLAVE_MASTER_OTA_GRACE_MS 300000u
 #define ESPNOW_ACCEL_INTERVAL_MS 16
 #define ESPNOW_BATTERY_INTERVAL_MS 30000
 #define SLAVE_BATTERY_AFTER_JOIN_MS 150
@@ -28,6 +30,7 @@
 static const char *TAG = "[ESPNOW_S]";
 
 static bool s_joined;
+static bool s_master_ota_grace;
 static bool s_accel_stream_enabled;
 static bool s_tap_notify_single;
 static bool s_tap_notify_double;
@@ -106,8 +109,18 @@ static esp_err_t send_battery_report(const uint8_t *dest_mac,
   return esp_now_core_send(dest_mac, &msg);
 }
 
+static uint32_t slave_master_lost_ms(void) {
+  if (ota_uart_is_active() || s_master_ota_grace) {
+    return SLAVE_MASTER_OTA_GRACE_MS;
+  }
+  return SLAVE_MASTER_LOST_MS;
+}
+
+static void touch_master_presence(uint32_t now) { s_last_discover_ms = now; }
+
 static void reset_join(void) {
   s_joined = false;
+  s_master_ota_grace = false;
   s_accel_stream_enabled = false;
   memset(s_master_mac, 0, sizeof(s_master_mac));
   s_last_discover_ms = 0;
@@ -216,6 +229,36 @@ static void handle_unicast_test(const uint8_t *master_mac,
            (unsigned long)test->seq, (int)s_joined);
 }
 
+static void handle_echo_ping(const uint8_t *master_mac,
+                             const alox_EspNowEchoPing *ping) {
+  if (ping == NULL || !s_joined ||
+      !esp_now_core_mac_equal(master_mac, s_master_mac)) {
+    return;
+  }
+
+  char mac_str[18];
+  esp_now_core_mac_to_str(master_mac, mac_str, sizeof(mac_str));
+  ESP_LOGI(TAG, "ESP-NOW PING recv from %s host_ts=%llu master_time_us=%llu",
+           mac_str, (unsigned long long)ping->host_timestamp_us,
+           (unsigned long long)ping->master_time_us);
+
+  alox_EspNowMessage msg = alox_EspNowMessage_init_zero;
+  msg.type = alox_EspNowMessageType_ESPNOW_ECHO_PONG;
+  msg.which_payload = alox_EspNowMessage_echo_pong_tag;
+  msg.payload.echo_pong.host_timestamp_us = ping->host_timestamp_us;
+  msg.payload.echo_pong.master_time_us = ping->master_time_us;
+
+  esp_err_t err = esp_now_core_send_fast(s_master_mac, &msg);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "ECHO PONG send failed: %s", esp_err_to_name(err));
+    return;
+  }
+
+  ESP_LOGI(TAG, "ESP-NOW PONG send to %s host_ts=%llu master_time_us=%llu",
+           mac_str, (unsigned long long)ping->host_timestamp_us,
+           (unsigned long long)ping->master_time_us);
+}
+
 static void handle_restart(const uint8_t *master_mac,
                            const alox_EspNowRestart *req) {
   const uint8_t *own = esp_now_core_own_mac();
@@ -358,8 +401,13 @@ static void handle_discover(const uint8_t *sender_mac,
     if (!esp_now_core_mac_equal(sender_mac, s_master_mac)) {
       return;
     }
-    if ((now - s_last_discover_ms) <= SLAVE_MASTER_LOST_MS) {
-      s_last_discover_ms = now;
+    s_master_ota_grace = discover->master_ota_pending;
+    if ((now - s_last_discover_ms) <= slave_master_lost_ms()) {
+      touch_master_presence(now);
+      return;
+    }
+    if (ota_uart_is_active()) {
+      touch_master_presence(now);
       return;
     }
     ESP_LOGW(TAG, "master lost, rejoining");
@@ -368,7 +416,8 @@ static void handle_discover(const uint8_t *sender_mac,
 
   memcpy(s_master_mac, sender_mac, ESP_NOW_ETH_ALEN);
   s_joined = true;
-  s_last_discover_ms = now;
+  s_master_ota_grace = discover->master_ota_pending;
+  touch_master_presence(now);
   esp_now_core_ensure_peer(sender_mac);
 
   char mac_str[18];
@@ -384,10 +433,14 @@ static void check_master_timeout(void) {
   if (!s_joined || s_last_discover_ms == 0) {
     return;
   }
+  if (ota_uart_is_active()) {
+    return;
+  }
   uint32_t now = esp_now_core_now_ms();
-  if ((now - s_last_discover_ms) > SLAVE_MASTER_LOST_MS) {
-    ESP_LOGW(TAG, "no master discover for %u ms, reconnecting",
-             (unsigned)(now - s_last_discover_ms));
+  uint32_t limit = slave_master_lost_ms();
+  if ((now - s_last_discover_ms) > limit) {
+    ESP_LOGW(TAG, "no master discover for %u ms (limit %u), reconnecting",
+             (unsigned)(now - s_last_discover_ms), (unsigned)limit);
     reset_join();
   }
 }
@@ -481,12 +534,16 @@ void esp_now_slave_on_recv(const esp_now_recv_info_t *info, const uint8_t *data,
 
   if (ota_uart_is_active()) {
     switch (msg.which_payload) {
+    case alox_EspNowMessage_discover_tag:
+      handle_discover(info->src_addr, &msg.payload.discover);
+      break;
     case alox_EspNowMessage_ota_start_tag:
     case alox_EspNowMessage_ota_payload_tag:
     case alox_EspNowMessage_ota_end_tag:
       if (!from_joined_master(info->src_addr)) {
         break;
       }
+      touch_master_presence(esp_now_core_now_ms());
       if (msg.which_payload == alox_EspNowMessage_ota_start_tag) {
         ota_espnow_slave_on_start(info->src_addr, &msg.payload.ota_start);
       } else if (msg.which_payload == alox_EspNowMessage_ota_payload_tag) {
@@ -510,6 +567,11 @@ void esp_now_slave_on_recv(const esp_now_recv_info_t *info, const uint8_t *data,
       handle_unicast_test(info->src_addr, &msg.payload.unicast_test);
     }
     break;
+  case alox_EspNowMessage_echo_ping_tag:
+    if (from_joined_master(info->src_addr)) {
+      handle_echo_ping(info->src_addr, &msg.payload.echo_ping);
+    }
+    break;
   case alox_EspNowMessage_accel_deadzone_tag:
     if (from_joined_master(info->src_addr)) {
       handle_accel_deadzone(info->src_addr, &msg.payload.accel_deadzone);
@@ -545,6 +607,11 @@ void esp_now_slave_on_recv(const esp_now_recv_info_t *info, const uint8_t *data,
       handle_restart(info->src_addr, &msg.payload.restart);
     }
     break;
+  case alox_EspNowMessage_ota_start_tag:
+    if (from_joined_master(info->src_addr)) {
+      ota_espnow_slave_on_start(info->src_addr, &msg.payload.ota_start);
+    }
+    break;
   default:
     ESP_LOGW(TAG, "unhandled which=%u type=%u", msg.which_payload,
              (unsigned)msg.type);