Improved audio lib and test app

firmware/libs/audio/Kconfig

@@ -21,7 +21,7 @@ if AUDIO
         help
           Set the audio sample rate in Hz. Common values are 8000, 16000, 44100, and 48000 Hz. Default is 16000 Hz.
 
-    config AUDIO_BIT_WIDTH
+    config AUDIO_WORD_WIDTH
         int "Audio Bit Depth"
         default 16
         range 8 32
@@ -51,7 +51,7 @@ if AUDIO
 
     config AUDIO_STACK_SIZE
         int "Audio Thread Stack Size (bytes)"
-        default 2048
+        default 1200
         range 256 8192
         help
           Set the stack size for the audio processing thread in bytes. Default is 2048 bytes.

firmware/libs/audio/include/audio.h

@@ -1,3 +1,21 @@
+/** 
+ * @file audio.h
+ * @brief Public API for the audio subsystem.
+ * This header defines the public interface for the audio subsystem, which
+ * provides functionality to play audio files and manage audio playback. It
+ * abstracts away the details of the underlying I2S peripheral and file
+ * system, allowing other parts of the application to easily trigger audio
+ * playback by specifying file paths or sound names.
+ * 
+ * FLASH MEMORY USAGE:
+ * LOG LEVEL DEBUG:   ~1.8 KB
+ * LOG LEVEL INFO:    ~1.7 KB
+ * LOG LEVEL WARNING: ~1.2 KB
+ * LOG LEVEL ERROR:   ~1.1 KB
+ * 
+ * RAM USAGE (without stack and audio buffers):
+ * Any LOG LEVEL:    ~0.47 KB
+ */
 #ifndef AUDIO_H
 #define AUDIO_H
 

firmware/libs/audio/src/audio.c

@@ -7,6 +7,10 @@
 
 LOG_MODULE_REGISTER(audio, CONFIG_AUDIO_LOG_LEVEL);
 
+#define SAMPLES_PER_BLOCK (CONFIG_AUDIO_BLOCK_SIZE / (CONFIG_AUDIO_WORD_WIDTH / 8) / 2) // Divide by 2 for stereo
+#define BLOCK_DURATION_MS ((SAMPLES_PER_BLOCK * 1000U) / CONFIG_AUDIO_SAMPLE_RATE)      // Duration of audio in each block in milliseconds
+#define MAX_WAIT_TIME_MS (3 * BLOCK_DURATION_MS)                                        // Maximum time to wait for the I2S peripheral to request the next block before we consider it stalled and reset it
+
 /* Get the I2S device from the devicetree */
 #define I2S_NODE DT_NODELABEL(i2s0)
 static const struct device *i2s_dev = DEVICE_DT_GET(I2S_NODE);
@@ -71,7 +75,7 @@ void audio_thread_fn(void *p1, void *p2, void *p3)
             while (!abort_playback)
             {
                 void *mem_block;
-                if (k_mem_slab_alloc(&audio_slab, &mem_block, K_MSEC(100)) < 0)
+                if (k_mem_slab_alloc(&audio_slab, &mem_block, K_MSEC(MAX_WAIT_TIME_MS)) < 0)
                 {
                     LOG_ERR("audio: slab timeout (I2S stall? DMA failure?) - skipping sound and resetting I2S...");
                     i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_DROP);
@@ -185,7 +189,7 @@ int audio_init(void)
 
     /* Initial configuration of the I2S peripheral */
     struct i2s_config config = {
-        .word_size = CONFIG_AUDIO_BIT_WIDTH,
+        .word_size = CONFIG_AUDIO_WORD_WIDTH,
         .channels = 2,
         .format = I2S_FMT_DATA_FORMAT_I2S,
         .options = I2S_OPT_BIT_CLK_MASTER | I2S_OPT_FRAME_CLK_MASTER,
@@ -202,7 +206,7 @@ int audio_init(void)
         return ret;
     }
 
-    LOG_DBG("I2S driver initialized and configured for %d Hz", CONFIG_AUDIO_SAMPLE_RATE);
+    LOG_DBG("Audio subsystem initialized successfully");
     return 0;
 }
 
@@ -217,7 +221,7 @@ int audio_play_file(const char *file)
     size_t len = strnlen(file, CONFIG_AUDIO_MAX_PATH_LEN);
     if (len >= CONFIG_AUDIO_MAX_PATH_LEN)
     {
-        LOG_ERR("audio_play_file: file path too long");
+        LOG_ERR("audio_play_file: file path too long: %s", file);
         return -ENAMETOOLONG;
     }
 
@@ -236,6 +240,18 @@ int audio_play_file(const char *file)
 
 int audio_play_sound(const char *file)
 {
+    if (file == NULL)
+    {
+        LOG_ERR("audio_play_sound: file name is NULL");
+        return -EINVAL;
+    }
+
+    size_t len = strnlen(file, CONFIG_AUDIO_MAX_PATH_LEN) + strlen(CONFIG_FS_MGMT_MOUNT_POINT) + strlen(CONFIG_AUDIO_SAMPLE_FOLDER) + 2;
+    if (len >= CONFIG_AUDIO_MAX_PATH_LEN)
+    {
+        LOG_ERR("audio_play_sound: file path too long: %s/%s/%s", CONFIG_FS_MGMT_MOUNT_POINT, CONFIG_AUDIO_SAMPLE_FOLDER, file);
+        return -ENAMETOOLONG;
+    }
     char path[CONFIG_AUDIO_MAX_PATH_LEN];
 
     snprintf(path, sizeof(path), "%s/%s/%s",