Send ESP-NOW accel only on deadzone change and harden BLE+WiFi OTA coex.

Quiet pods no longer spam 100 Hz samples; mute wifi logs and throttle BLE
notifies during slave distribution so the wifi task stack does not panic.

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

main/ble_host.c

@@ -3,6 +3,7 @@
 #include "esp_timer.h"
 #include "host_transport.h"
 #include "nvs_flash.h"
+#include "ota_espnow.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/semphr.h"
 #include "freertos/task.h"
@@ -26,9 +27,12 @@ static const char *DEVICE_NAME = "Powerpod";
 /** Prefer large ATT MTU so CLIENT_INFO / BATTERY fit in fewer notify chunks. */
 #define BLE_PREFERRED_ATT_MTU 517
 #define BLE_NOTIFY_CHUNK_RETRIES 24
+/** During ESP-NOW OTA dist, fail notify sooner so WiFi/ESP-NOW keeps airtime. */
+#define BLE_NOTIFY_CHUNK_RETRIES_OTA_DIST 4
 #define BLE_NOTIFY_CHUNK_RETRY_MS 5
 /** Pace multi-chunk notifies so the central parser sees contiguous frame bytes. */
 #define BLE_NOTIFY_CHUNK_GAP_MS 8
+#define BLE_NOTIFY_CHUNK_GAP_OTA_DIST_MS 2
 
 /*
  * Nordic UART style:
@@ -73,7 +77,10 @@ uint16_t ble_host_max_payload(void) {
  * One ATT notification (≤ MTU-3). Retries on transient NimBLE buffer pressure.
  */
 static esp_err_t ble_notify_chunk(const uint8_t *data, uint16_t len) {
-  for (int attempt = 0; attempt < BLE_NOTIFY_CHUNK_RETRIES; attempt++) {
+  const int max_retries = ota_espnow_distribution_active()
+                              ? BLE_NOTIFY_CHUNK_RETRIES_OTA_DIST
+                              : BLE_NOTIFY_CHUNK_RETRIES;
+  for (int attempt = 0; attempt < max_retries; attempt++) {
     struct os_mbuf *om = ble_hs_mbuf_from_flat(data, len);
     if (om == NULL) {
       vTaskDelay(pdMS_TO_TICKS(BLE_NOTIFY_CHUNK_RETRY_MS));
@@ -140,7 +147,10 @@ static esp_err_t ble_host_tx(const uint8_t *frame, size_t frame_len) {
     }
     off += n;
     if (off < frame_len) {
-      vTaskDelay(pdMS_TO_TICKS(BLE_NOTIFY_CHUNK_GAP_MS));
+      const uint32_t gap_ms = ota_espnow_distribution_active()
+                                 ? BLE_NOTIFY_CHUNK_GAP_OTA_DIST_MS
+                                 : BLE_NOTIFY_CHUNK_GAP_MS;
+      vTaskDelay(pdMS_TO_TICKS(gap_ms));
     }
   }
 

main/bosch456.c

@@ -2,7 +2,7 @@
  * BMA456H integration for Powerpod (ESP-IDF I2C master + Bosch SensorAPI).
  *
  * Polls accelerometer at 10 Hz; tap events arrive on BMA456_INT_GPIO.
- * Accel logging is filtered in software (deadzone); slaves stream samples via ESP-NOW.
+ * Accel log + ESP-NOW stream share a software deadzone filter (emit on change).
  */
 
 #include "bosch456.h"
@@ -33,6 +33,10 @@ static int16_t s_last_x;
 static int16_t s_last_y;
 static int16_t s_last_z;
 static bool s_have_last_sample;
+static int16_t s_stream_last_x;
+static int16_t s_stream_last_y;
+static int16_t s_stream_last_z;
+static bool s_stream_have_last;
 
 static volatile bool s_int_pending;
 static SemaphoreHandle_t s_accel_mutex;
@@ -119,6 +123,7 @@ bool bma456_is_ready(void) { return s_bma456_ready; }
 void bma456_set_accel_deadzone(uint32_t deadzone_lsb) {
   s_accel_deadzone = deadzone_lsb;
   s_have_last_sample = false;
+  s_stream_have_last = false;
   if (s_bma456_ready) {
     ESP_LOGI(TAG, "accel deadzone %lu LSB", (unsigned long)deadzone_lsb);
   }
@@ -126,6 +131,23 @@ void bma456_set_accel_deadzone(uint32_t deadzone_lsb) {
 
 uint32_t bma456_get_accel_deadzone(void) { return s_accel_deadzone; }
 
+void bma456_accel_stream_reset_baseline(void) { s_stream_have_last = false; }
+
+bool bma456_accel_stream_take_if_changed(int16_t x, int16_t y, int16_t z) {
+  if (s_stream_have_last) {
+    if (axis_delta(x, s_stream_last_x) <= (int16_t)s_accel_deadzone &&
+        axis_delta(y, s_stream_last_y) <= (int16_t)s_accel_deadzone &&
+        axis_delta(z, s_stream_last_z) <= (int16_t)s_accel_deadzone) {
+      return false;
+    }
+  }
+  s_stream_last_x = x;
+  s_stream_last_y = y;
+  s_stream_last_z = z;
+  s_stream_have_last = true;
+  return true;
+}
+
 bool bma456_tap_config_valid(const bma456_tap_config_t *cfg) {
   if (cfg == NULL) {
     return false;

main/bosch456.h

@@ -19,7 +19,7 @@
 /** Sensor interrupt line → ESP32 GPIO (active high, rising edge). */
 #define BMA456_INT_GPIO 10
 
-/** Software filter: log accel only when |axis - last| > deadzone (raw LSB). */
+/** Software filter: emit accel only when |axis - last| > deadzone (raw LSB). */
 #define BMA456_DEFAULT_ACCEL_DEADZONE 100u
 
 /**
@@ -81,6 +81,16 @@ bool bma456_is_ready(void);
 void bma456_set_accel_deadzone(uint32_t deadzone_lsb);
 uint32_t bma456_get_accel_deadzone(void);
 
+/**
+ * ESP-NOW stream filter: true if sample exceeds deadzone vs last streamed
+ * sample (or no baseline yet). On true, commits (x,y,z) as stream baseline.
+ * Independent of the log filter baseline.
+ */
+bool bma456_accel_stream_take_if_changed(int16_t x, int16_t y, int16_t z);
+
+/** Force next stream take to accept (call when accel stream is enabled). */
+void bma456_accel_stream_reset_baseline(void);
+
 /** Log accel when any axis moved more than deadzone since last reported sample. */
 void bma456_report_accel_if_changed(int16_t x, int16_t y, int16_t z);
 

main/cmd/cmd_ota.c

@@ -5,8 +5,10 @@
 #include "pod_reboot.h"
 #include "uart_cmd.h"
 #include "esp_log.h"
+#include "esp_timer.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/idf_additions.h"
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -32,6 +34,14 @@ typedef struct {
   uint32_t written;
   int slot;
 } ota_dist_job_t;
+
+/** Cap host DISTRIBUTING pushes (BLE notifies compete with ESP-NOW OTA TX). */
+#define OTA_DIST_NOTIFY_MIN_US (250 * 1000ull)
+
+static int64_t s_last_dist_agg_us;
+static int64_t s_last_dist_slave_us;
+static uint32_t s_last_dist_agg_bytes = UINT32_MAX;
+
 static void send_ota_status(ota_uart_status_t status, uint32_t err_code) {
   alox_UartMessage response;
   uart_cmd_init_response(&response, alox_MessageType_OTA_STATUS,
@@ -64,15 +74,33 @@ static void send_ota_distributing(uint32_t kind, uint32_t bytes_done,
 
 static void ota_dist_aggregate(uint32_t bytes_done, uint32_t total_bytes,
                                uint8_t slave_count) {
-  (void)slave_count;
   led_ring_show_ota_progress(bytes_done, total_bytes, OTA_LED_ESPNOW_TX_R,
                              OTA_LED_ESPNOW_TX_G, OTA_LED_ESPNOW_TX_B);
+
+  const int64_t now = esp_timer_get_time();
+  const bool first = (s_last_dist_agg_bytes == UINT32_MAX);
+  const bool boundary =
+      (bytes_done == 0) || (total_bytes > 0 && bytes_done >= total_bytes);
+  const bool paced =
+      (now - s_last_dist_agg_us) >= (int64_t)OTA_DIST_NOTIFY_MIN_US;
+  if (!first && !boundary && !paced) {
+    return;
+  }
+  s_last_dist_agg_us = now;
+  s_last_dist_agg_bytes = bytes_done;
   send_ota_distributing(OTA_DIST_AGGREGATE, bytes_done, (uint32_t)slave_count);
 }
 
 static void ota_dist_per_slave(uint32_t slave_id, uint32_t bytes_done,
                              uint32_t total_bytes) {
   (void)total_bytes;
+  /* Host also polls OTA_SLAVE_PROGRESS; keep per-slave pushes rare on BLE. */
+  const int64_t now = esp_timer_get_time();
+  if ((now - s_last_dist_slave_us) < (int64_t)OTA_DIST_NOTIFY_MIN_US &&
+      bytes_done > 0) {
+    return;
+  }
+  s_last_dist_slave_us = now;
   send_ota_distributing(OTA_DIST_PER_SLAVE, bytes_done, slave_id);
 }
 
@@ -225,6 +253,9 @@ static void ota_distribute_task(void *param) {
 
   led_ring_show_ota_progress(0, image_size, OTA_LED_ESPNOW_TX_R, OTA_LED_ESPNOW_TX_G,
                              OTA_LED_ESPNOW_TX_B);
+  s_last_dist_agg_us = 0;
+  s_last_dist_slave_us = 0;
+  s_last_dist_agg_bytes = UINT32_MAX;
   send_ota_distributing(OTA_DIST_AGGREGATE, 0, 0);
 
   esp_err_t err = ota_espnow_distribute(part, image_size, &s_dist_progress);
@@ -315,6 +346,10 @@ static void ota_start_espnow_task(void *param) {
     return;
   }
 
+  s_last_dist_agg_us = 0;
+  s_last_dist_slave_us = 0;
+  s_last_dist_agg_bytes = UINT32_MAX;
+
   esp_err_t err = ota_espnow_distribute(part, image_size, &s_dist_progress);
   if (err != ESP_OK) {
     send_ota_failed(42);

main/esp_now_core.c

@@ -280,6 +280,14 @@ esp_err_t esp_now_core_init_radio(uint8_t channel) {
   ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE));
   ESP_ERROR_CHECK(esp_wifi_set_channel(channel, WIFI_SECOND_CHAN_NONE));
 
+  /* WiFi task stack is tiny; ERROR logs from pp/coex (e.g. under BLE+ESP-NOW
+   * OTA) call esp_log_write on that stack and can overflow → panic reboot.
+   * Mute after esp_wifi_init (which resets the wifi tag to default level). */
+  esp_log_level_set("wifi", ESP_LOG_NONE);
+  esp_log_level_set("wifi_init", ESP_LOG_WARN);
+  esp_log_level_set("coex", ESP_LOG_WARN);
+  esp_log_level_set("NimBLE", ESP_LOG_WARN);
+
   ESP_ERROR_CHECK(esp_read_mac(s_own_mac, ESP_MAC_WIFI_STA));
   s_wifi_channel = channel;
   return ESP_OK;

main/esp_now_master.c

@@ -780,7 +780,11 @@ static void monitor_task(void *param) {
 
   while (1) {
     vTaskDelay(pdMS_TO_TICKS(ESPNOW_HEARTBEAT_INTERVAL_MS));
-    client_registry_check_timeouts(ESPNOW_CLIENT_TIMEOUT_MS);
+    /* During ESP-NOW OTA dist the recv_cb drops heartbeats; do not wipe
+     * targets from the registry while they are still being updated. */
+    if (!ota_espnow_distribution_active()) {
+      client_registry_check_timeouts(ESPNOW_CLIENT_TIMEOUT_MS);
+    }
 
     uint32_t t = esp_now_core_now_ms();
     if (t - last_local_battery_ms >= ESPNOW_BATTERY_INTERVAL_MS) {

main/esp_now_slave.c

@@ -26,7 +26,8 @@
 /** While master or slave OTA is in progress (discover may be sparse). */
 #define SLAVE_MASTER_OTA_GRACE_MS 300000u
 /**
- * Accel stream cadence (10 ms frame). TX path is selectable (INPUT_SEND_MODE).
+ * Accel stream poll cadence (10 ms frame). TX only when sample exceeds the
+ * BMA456 deadzone vs last sent sample. TX path is selectable (INPUT_SEND_MODE).
  * With master Discover.master_time_us, slaves phase into 1 ms slots:
  * offset_ms = (assigned_id - 1) % 8. Slot wait uses esp_timer (FreeRTOS tick
  * is 10 ms — too coarse for intra-frame offsets).
@@ -516,6 +517,9 @@ static void handle_accel_stream(const uint8_t *master_mac,
     return;
   }
   s_accel_stream_enabled = cfg->enable;
+  if (cfg->enable) {
+    bma456_accel_stream_reset_baseline();
+  }
   char mac_str[18];
   esp_now_core_mac_to_str(master_mac, mac_str, sizeof(mac_str));
   ESP_LOGI(TAG, "accel stream %s from master %s (id=%lu)",
@@ -743,7 +747,8 @@ static void accel_stream_task(void *param) {
   (void)param;
 
   ESP_LOGI(TAG,
-           "accel stream task (interval %u ms, %u×%llu us slots, mode selectable)",
+           "accel stream task (poll %u ms, deadzone TX, %u×%llu us slots, "
+           "mode selectable)",
            (unsigned)ESPNOW_ACCEL_INTERVAL_MS, (unsigned)ESPNOW_ACCEL_SLOT_COUNT,
            (unsigned long long)ESPNOW_ACCEL_SLOT_US);
 
@@ -759,6 +764,9 @@ static void accel_stream_task(void *param) {
     if (bma456_read_accel(&x, &y, &z) != ESP_OK) {
       continue;
     }
+    if (!bma456_accel_stream_take_if_changed(x, y, z)) {
+      continue;
+    }
     (void)send_accel_sample(s_master_mac, s_assigned_id, x, y, z);
   }
 }