esp32 improvements

- better clock seconds
- better alarm (image before audio, supposedly)

components/audio_client/audio_client.cpp

@@ -35,6 +35,7 @@ static uint8_t s_img_buf[STATUS_IMG_BYTES];
 static lv_img_dsc_t s_img_dsc;
 static volatile bool s_img_pending = false;   /* expecting binary frame with image data */
 static volatile bool s_img_updated = false;   /* new image ready for UI consumption */
+static TaskHandle_t s_img_notify_task = NULL;  /* task to wake on new image */
 
 /* Forward declarations */
 static void playback_task(void *arg);
@@ -121,6 +122,9 @@ static void handle_binary_frame(const uint8_t *data, int len)
         if (len == STATUS_IMG_BYTES) {
             memcpy(s_img_buf, data, STATUS_IMG_BYTES);
             s_img_updated = true;
+            if (s_img_notify_task) {
+                xTaskNotifyGive(s_img_notify_task);
+            }
             ESP_LOGI(TAG, "Status image received (%d bytes)", len);
         } else {
             ESP_LOGW(TAG, "Status image size mismatch: got %d, expected %d", len, STATUS_IMG_BYTES);
@@ -262,6 +266,11 @@ audio_state_t audio_client_get_state(void)
     return s_state;
 }
 
+void audio_client_set_image_notify_task(TaskHandle_t task)
+{
+    s_img_notify_task = task;
+}
+
 const lv_img_dsc_t *audio_client_get_status_image(bool *updated)
 {
     if (updated) {

components/audio_client/audio_client.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include <stdbool.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
 #include "lvgl.h"
 
 #ifdef __cplusplus
@@ -30,6 +32,12 @@ void audio_client_stop(void);
 /** Get current audio client state. */
 audio_state_t audio_client_get_state(void);
 
+/**
+ * Register a task to be notified (via xTaskNotifyGive) when a new status
+ * image arrives.  Call before audio_client_start().
+ */
+void audio_client_set_image_notify_task(TaskHandle_t task);
+
 /**
  * Get the latest status image descriptor.
  * @param updated  Set to true if a new image arrived since last call, then reset.

components/user_app/user_app.cpp

@@ -82,11 +82,13 @@ void UserApp_TaskInit(void)
     /* Start WebSocket client */
     ws_client_start();
 
-    /* Start audio streaming client */
-    audio_client_start();
-
     /* Sensor polling task - Core 1, 4KB stack */
-    xTaskCreatePinnedToCore(sensor_task, "sensor", 4 * 1024, NULL, 3, NULL, 1);
+    TaskHandle_t sensor_handle = NULL;
+    xTaskCreatePinnedToCore(sensor_task, "sensor", 4 * 1024, NULL, 3, &sensor_handle, 1);
+
+    /* Start audio streaming client, notify sensor task on new images */
+    audio_client_set_image_notify_task(sensor_handle);
+    audio_client_start();
 
     /* Button handling task - Core 1 */
     xTaskCreatePinnedToCore(button_task, "button", 2 * 1024, NULL, 2, NULL, 1);
@@ -182,9 +184,32 @@ static void sensor_task(void *arg)
     float temp = 0, humidity = 0;
     rtcTimeStruct_t rtc_time = {};
     int sensor_divider = 0;
+    TickType_t last_sensor_tick = xTaskGetTickCount();
 
     for (;;) {
-        /* Read RTC every second */
+        /*
+         * Sleep until either:
+         *   - a new status image arrives (xTaskNotifyGive from audio_client), or
+         *   - 1 second elapses (clock refresh cadence)
+         */
+        ulTaskNotifyTake(pdTRUE, pdMS_TO_TICKS(1000));
+
+        /* Check for status image updates immediately */
+        bool img_updated = false;
+        const lv_img_dsc_t *img = audio_client_get_status_image(&img_updated);
+        if (img_updated && Lvgl_lock(100)) {
+            dashboard_ui_update_status_image(img);
+            Lvgl_unlock();
+        }
+
+        /* Sensor + clock updates at ~1s cadence (skip if woken early) */
+        TickType_t now = xTaskGetTickCount();
+        if ((now - last_sensor_tick) < pdMS_TO_TICKS(900)) {
+            continue;
+        }
+        last_sensor_tick = now;
+
+        /* Read RTC */
         Rtc_GetTime(&rtc_time);
 
         /* Read SHTC3 + battery every 5 seconds */
@@ -203,23 +228,13 @@ static void sensor_task(void *arg)
         }
         sensor_divider = (sensor_divider + 1) % 5;
 
-        /* Update clock every second */
+        /* Update clock */
         if (Lvgl_lock(100)) {
             dashboard_ui_update_time(rtc_time.hour, rtc_time.minute, rtc_time.second,
                                      rtc_time.year, rtc_time.month, rtc_time.day,
                                      rtc_time.week);
             Lvgl_unlock();
         }
-
-        /* Poll for status image updates */
-        bool img_updated = false;
-        const lv_img_dsc_t *img = audio_client_get_status_image(&img_updated);
-        if (img_updated && Lvgl_lock(100)) {
-            dashboard_ui_update_status_image(img);
-            Lvgl_unlock();
-        }
-
-        vTaskDelay(pdMS_TO_TICKS(1000));
     }
 }