diff --git a/software/.vscode/settings.json b/software/.vscode/settings.json
index 6fa0935..bff4832 100644
--- a/software/.vscode/settings.json
+++ b/software/.vscode/settings.json
@@ -36,6 +36,7 @@
         "numbers": "c",
         "systick.h": "c",
         "critical_section.h": "c",
-        "serializers.h": "c"
+        "serializers.h": "c",
+        "cstring": "c"
     }
 }
\ No newline at end of file
diff --git a/software/platform/raspberry-pico-w/pico_hal_wrapper.c b/software/platform/raspberry-pico-w/pico_hal_wrapper.c
index 7c4317c..78ab591 100644
--- a/software/platform/raspberry-pico-w/pico_hal_wrapper.c
+++ b/software/platform/raspberry-pico-w/pico_hal_wrapper.c
@@ -1,4 +1,9 @@
 
+
+// C library
+#include <string.h>
+#include <stdlib.h>
+
 // OST common files
 #include "ost_hal.h"
 #include "debug.h"
@@ -22,33 +27,10 @@
 #include "audio_player.h"
 #include "pico_i2s.h"
 
-static volatile uint32_t msTicks = 0;
-static audio_ctx_t audio_ctx;
+// ===========================================================================================================
+// CONSTANTS / DEFINES
+// ===========================================================================================================
 
-void __isr __time_critical_func(audio_i2s_dma_irq_handler)();
-
-// ----------------------------------------------------------------------------
-// SYSTEM HAL
-// ----------------------------------------------------------------------------
-
-#define UART_ID uart0
-#define BAUD_RATE 115200
-
-// We are using pins 0 and 1, but see the GPIO function select table in the
-// datasheet for information on which other pins can be used.
-#define UART_TX_PIN 0
-#define UART_RX_PIN 1
-
-static struct repeating_timer sys_timer;
-
-// static audio_i2s_config_t i2s_config = {28, 26, 0};
-
-static __attribute__((aligned(8))) pio_i2s i2s;
-
-void ost_system_delay_ms(uint32_t delay)
-{
-  busy_wait_ms(delay);
-}
 const uint8_t LED_PIN = 14; // GP 14
 
 const uint8_t LCD_DC = 8;
@@ -66,18 +48,36 @@ const uint8_t ROTARY_BUTTON = 3;
 const uint8_t SD_CARD_CS = 17;
 const uint8_t SD_CARD_PRESENCE = 24;
 
-static bool sys_timer_callback(struct repeating_timer *t)
-{
-  msTicks++;
+#define UART_ID uart0
+#define BAUD_RATE 115200
 
-  // qor_switch_context();
+// We are using pins 0 and 1, but see the GPIO function select table in the
+// datasheet for information on which other pins can be used.
+#define UART_TX_PIN 0
+#define UART_RX_PIN 1
 
-  return true;
-}
+// ===========================================================================================================
+// GLOBAL VARIABLES
+// ===========================================================================================================
+static __attribute__((aligned(8))) pio_i2s i2s;
+static volatile uint32_t msTicks = 0;
+static audio_ctx_t audio_ctx;
 
+// ===========================================================================================================
+// PROTOTYPES
+// ===========================================================================================================
 extern void init_spi(void);
-
 void dma_init();
+void __isr __time_critical_func(audio_i2s_dma_irq_handler)();
+
+// ===========================================================================================================
+// OST HAL IMPLEMENTATION
+// ===========================================================================================================
+
+void ost_system_delay_ms(uint32_t delay)
+{
+  busy_wait_ms(delay);
+}
 
 void gpio_callback(uint gpio, uint32_t events)
 {
@@ -167,15 +167,10 @@ void ost_system_initialize()
       .data_pin = 28,
       .clock_pin_base = 26};
 
-  // i2s_program_start_synched(pio0, audio_i2s_dma_irq_handler, &i2s, &config);
-
-  // pico_i2s_setup(&config);
+  i2s_program_setup(pio0, audio_i2s_dma_irq_handler, &i2s, &config);
 
   audio_init(&audio_ctx);
 
-  //------------------- System timer (1ms)
-  // add_repeating_timer_ms(1, sys_timer_callback, NULL, &sys_timer);
-
   // ------------ Everything is initialized, print stuff here
   debug_printf("System Clock: %lu\n", clock_get_hz(clk_sys));
 }
@@ -304,21 +299,20 @@ void ost_display_transfer_multi(uint8_t *buff, uint32_t btr)
 // AUDIO HAL
 // ----------------------------------------------------------------------------
 
-// extern shared_state_t shared_state;
-
-// #include "pico/critical_section.h"
-
-// critical_section_t acrit;
-
 void ost_audio_play(const char *filename)
 {
-
   audio_play(&audio_ctx, filename);
 
-  // audio_i2s_set_enabled(true);
-  // audio_process(&audio_ctx);
+  i2s.buffer_index = 0;
 
-  // audio_step = 1;
+  // On appelle une première fois le process pour récupérer et initialiser le premier buffer...
+  audio_process(&audio_ctx);
+
+  // Puis le deuxième ... (pour avoir un buffer d'avance)
+  audio_process(&audio_ctx);
+
+  // On lance les DMA
+  i2s_start(&i2s);
 }
 
 int ost_audio_process()
@@ -326,39 +320,39 @@ int ost_audio_process()
   return audio_process(&audio_ctx);
 }
 
+static ost_audio_callback_t AudioCallBack = NULL;
+
 void ost_audio_register_callback(ost_audio_callback_t cb)
 {
+  AudioCallBack = cb;
 }
 
-void ost_hal_audio_frame_end()
+void ost_hal_audio_new_frame(const void *buff, int dma_trans_number)
 {
+  if (dma_trans_number > STEREO_BUFFER_SIZE)
+  {
+    // Problème
+    return;
+  }
+  memcpy(i2s.out_ctrl_blocks[i2s.buffer_index], buff, dma_trans_number * sizeof(uint32_t));
+  i2s.buffer_index = 1 - i2s.buffer_index;
 
-  // uint dma_channel = shared_state.dma_channel;
-  // if (dma_irqn_get_channel_status(PICO_AUDIO_I2S_DMA_IRQ, dma_channel))
-  // {
-  //   dma_irqn_acknowledge_channel(PICO_AUDIO_I2S_DMA_IRQ, dma_channel);
-  // }
-}
-
-void ost_hal_audio_frame_start(const volatile void *buff, int dma_trans_number)
-{
+  //
   // dma_channel_transfer_from_buffer_now(shared_state.dma_channel, buff, dma_trans_number);
   // dma_channel_start(shared_state.dma_channel);
 
-  dma_hw->ints0 = 1u << i2s.dma_ch_out_data; // clear the IRQ
+  //  dma_hw->ints0 = 1u << i2s.dma_ch_out_data; // clear the IRQ
 }
 
 void __isr __time_critical_func(audio_i2s_dma_irq_handler)()
 {
-  /*
-  uint dma_channel = shared_state.dma_channel;
-  if (dma_irqn_get_channel_status(PICO_AUDIO_I2S_DMA_IRQ, dma_channel))
-  {
-    dma_irqn_acknowledge_channel(PICO_AUDIO_I2S_DMA_IRQ, dma_channel);
-  }
+  dma_hw->ints0 = 1u << i2s.dma_ch_out_data; // clear the IRQ
 
-  audio_process(&audio_ctx);
-  */
+  // Warn the application layer that we have done on that channel
+  if (AudioCallBack != NULL)
+  {
+    AudioCallBack();
+  }
 }
 
 #if 0 // legacy audio test
diff --git a/software/platform/raspberry-pico-w/pico_i2s.c b/software/platform/raspberry-pico-w/pico_i2s.c
index 8a75014..c44a0b7 100644
--- a/software/platform/raspberry-pico-w/pico_i2s.c
+++ b/software/platform/raspberry-pico-w/pico_i2s.c
@@ -16,10 +16,10 @@
 
 #include "debug.h"
 
-void pico_i2s_set_frequency(const audio_i2s_config_t *config)
+void pico_i2s_set_frequency(const pio_i2s *i2s, const audio_i2s_config_t *config)
 {
     float bitClk = config->freq * config->bps * 2.0 /* channels */ * 2.0 /* edges per clock */;
-    //  pio_sm_set_clkdiv(audio_pio, shared_state.pio_sm, (float)clock_get_hz(clk_sys) / bitClk);
+    pio_sm_set_clkdiv(i2s->pio, i2s->sm_dout, (float)clock_get_hz(clk_sys) / bitClk);
 }
 
 #if 0
@@ -64,7 +64,7 @@ void audio_i2s_set_enabled(bool enabled)
 
 //---------------------------------------------------------------------------------------------------------------------------
 
-static void dma_double_buffer_init(pio_i2s *i2s, void (*dma_handler)(void))
+static void dma_double_buffer_init(pio_i2s *i2s)
 {
     i2s->dma_ch_out_ctrl = dma_claim_unused_channel(true);
     i2s->dma_ch_out_data = dma_claim_unused_channel(true);
@@ -75,14 +75,25 @@ static void dma_double_buffer_init(pio_i2s *i2s, void (*dma_handler)(void))
     dma_channel_config c = dma_channel_get_default_config(i2s->dma_ch_out_ctrl);
     channel_config_set_read_increment(&c, true);
     channel_config_set_write_increment(&c, false);
+
+    // i2s->out_ctrl_blocks pointe sur deux emplacements, 4 octets par emplacement (qui est une adresse)
+    // A chaque fois que le DMA de contrôle sera activé, l'adresse va s'incrémenter de 4 octets  (DMA_SIZE_32)
+    // Dès lors :
+    //  - On commence à l'index 0
+    //  - Puis l'index 1
+    // On va revenir à l'index 0 tous les ... 8 octets, donc on programme ce décalage (3 bits)
     channel_config_set_ring(&c, false, 3);
     channel_config_set_transfer_data_size(&c, DMA_SIZE_32);
     dma_channel_configure(i2s->dma_ch_out_ctrl, &c, &dma_hw->ch[i2s->dma_ch_out_data].al3_read_addr_trig, i2s->out_ctrl_blocks, 1, false);
 
+    // la destination est l'alias al3_read_addr_trig qui va donc modifier l'adresse de début du transfer DMA et enclencher le démarrage
+    // Nous avons deux actions, c'est pour cela que c'est un alias
+
     c = dma_channel_get_default_config(i2s->dma_ch_out_data);
     channel_config_set_read_increment(&c, true);
     channel_config_set_write_increment(&c, false);
-    channel_config_set_chain_to(&c, i2s->dma_ch_out_ctrl);
+    channel_config_set_transfer_data_size(&c, DMA_SIZE_32);
+    channel_config_set_chain_to(&c, i2s->dma_ch_out_ctrl); // On va chaîner ce DMA au contrôle: lorsque le DMA est terminé, le DMA de contrôle va s'activer... et ainsi de suite
     channel_config_set_dreq(&c, pio_get_dreq(i2s->pio, i2s->sm_dout, true));
 
     dma_channel_configure(i2s->dma_ch_out_data,
@@ -91,15 +102,9 @@ static void dma_double_buffer_init(pio_i2s *i2s, void (*dma_handler)(void))
                           NULL,
                           STEREO_BUFFER_SIZE,
                           false);
-
-    dma_channel_set_irq0_enabled(i2s->dma_ch_out_data, true);
-    irq_set_exclusive_handler(DMA_IRQ_0, dma_handler);
-    irq_set_enabled(DMA_IRQ_0, true);
-
-    dma_channel_start(i2s->dma_ch_out_ctrl);
 }
 
-static void i2s_sync_program_init(PIO pio, pio_i2s *i2s, audio_i2s_config_t *config)
+static void i2s_sync_program_init(PIO pio, pio_i2s *i2s, const audio_i2s_config_t *config)
 {
     uint offset = 0;
     i2s->pio = pio;
@@ -110,13 +115,46 @@ static void i2s_sync_program_init(PIO pio, pio_i2s *i2s, audio_i2s_config_t *con
     offset = pio_add_program(pio0, &i2s_out_master_program);
     // 4th argument is bit depth, 5th dout, 6th bclk pin base (lrclk is bclk pin + 1)
     i2s_out_master_program_init(pio, i2s->sm_dout, offset, config->bps, config->data_pin, config->clock_pin_base);
-    //  pio_sm_set_clkdiv(pio, i2s->sm_dout, 89); // Approximately 11KHz audio
 }
 
-void i2s_program_start_synched(PIO pio, void (*dma_handler)(void), pio_i2s *i2s, audio_i2s_config_t *config)
+void i2s_program_setup(PIO pio, void (*dma_handler)(void), pio_i2s *i2s, const audio_i2s_config_t *config)
 {
-    // i2s_sync_program_init(pio, i2s);
-    pico_i2s_set_frequency(config);
-    dma_double_buffer_init(i2s, dma_handler);
+    if (((uint32_t)i2s & 0x7) != 0)
+    {
+        debug_printf("pio_i2s argument must be 8-byte aligned!\r\n");
+    }
+
+    i2s_sync_program_init(pio, i2s, config);
+    pico_i2s_set_frequency(i2s, config); // call after PIO configuration
+    dma_double_buffer_init(i2s);
+    irq_set_exclusive_handler(DMA_IRQ_0, dma_handler);
     pio_enable_sm_mask_in_sync(i2s->pio, i2s->sm_mask);
 }
+
+void i2s_start(pio_i2s *i2s)
+{
+    // D'abord on va paramétrer les diverses interruptions
+    dma_channel_set_irq0_enabled(i2s->dma_ch_out_data, true);
+    irq_set_enabled(DMA_IRQ_0, true);
+
+    // YAAAAAAA on lance!
+    dma_channel_start(i2s->dma_ch_out_ctrl);
+}
+
+static void pico_gracefully_stop_dma(uint channel)
+{
+    // See errata sheet to avoid spurious interrupts
+    // disable the channel on IRQ0
+    dma_channel_set_irq0_enabled(channel, false);
+    // abort the channel
+    dma_channel_abort(channel);
+    // clear the spurious IRQ (if there was one)
+    dma_channel_acknowledge_irq0(channel);
+}
+
+void i2s_stop(pio_i2s *i2s)
+{
+    pico_gracefully_stop_dma(i2s->dma_ch_out_ctrl);
+    pico_gracefully_stop_dma(i2s->dma_ch_out_data);
+    irq_set_enabled(DMA_IRQ_0, false);
+}
diff --git a/software/platform/raspberry-pico-w/pico_i2s.h b/software/platform/raspberry-pico-w/pico_i2s.h
index 033b9c5..257bdb0 100644
--- a/software/platform/raspberry-pico-w/pico_i2s.h
+++ b/software/platform/raspberry-pico-w/pico_i2s.h
@@ -13,158 +13,15 @@
 #include "hardware/irq.h"
 #include "hardware/pio.h"
 
+#include "audio_player.h"
+
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
-#if 0
-
-/** \file audio_i2s.h
- *  \defgroup pico_audio_i2s pico_audio_i2s
- *  I2S audio output using the PIO
- *
- * This library uses the \ref hardware_pio system to implement a I2S audio interface
- *
- * \todo Must be more we need to say here.
- * \todo certainly need an example
- *
- */
-
-#ifndef PICO_AUDIO_I2S_DMA_IRQ
-#ifdef PICO_AUDIO_DMA_IRQ
-#define PICO_AUDIO_I2S_DMA_IRQ PICO_AUDIO_DMA_IRQ
-#else
-#define PICO_AUDIO_I2S_DMA_IRQ 0
-#endif
-#endif
-
-#ifndef PICO_AUDIO_I2S_PIO
-#ifdef PICO_AUDIO_PIO
-#define PICO_AUDIO_I2S_PIO PICO_AUDIO_PIO
-#else
-#define PICO_AUDIO_I2S_PIO 0
-#endif
-#endif
-
-#if !(PICO_AUDIO_I2S_DMA_IRQ == 0 || PICO_AUDIO_I2S_DMA_IRQ == 1)
-#error PICO_AUDIO_I2S_DMA_IRQ must be 0 or 1
-#endif
-
-#if !(PICO_AUDIO_I2S_PIO == 0 || PICO_AUDIO_I2S_PIO == 1)
-#error PICO_AUDIO_I2S_PIO ust be 0 or 1
-#endif
-
-#ifndef PICO_AUDIO_I2S_MAX_CHANNELS
-#ifdef PICO_AUDIO_MAX_CHANNELS
-#define PICO_AUDIO_I2S_MAX_CHANNELS PICO_AUDIO_MAX_CHANNELS
-#else
-#define PICO_AUDIO_I2S_MAX_CHANNELS 2u
-#endif
-#endif
-
-#ifndef PICO_AUDIO_I2S_BUFFERS_PER_CHANNEL
-#ifdef PICO_AUDIO_BUFFERS_PER_CHANNEL
-#define PICO_AUDIO_I2S_BUFFERS_PER_CHANNEL PICO_AUDIO_BUFFERS_PER_CHANNEL
-#else
-#define PICO_AUDIO_I2S_BUFFERS_PER_CHANNEL 3u
-#endif
-#endif
-
-#ifndef PICO_AUDIO_I2S_BUFFER_SAMPLE_LENGTH
-#ifdef PICO_AUDIO_BUFFER_SAMPLE_LENGTH
-#define PICO_AUDIO_I2S_BUFFER_SAMPLE_LENGTH PICO_AUDIO_BUFFER_SAMPLE_LENGTH
-#else
-#define PICO_AUDIO_I2S_BUFFER_SAMPLE_LENGTH 576u
-#endif
-#endif
-
-#ifndef PICO_AUDIO_I2S_SILENCE_BUFFER_SAMPLE_LENGTH
-#ifdef PICO_AUDIO_I2S_SILENCE_BUFFER_SAMPLE_LENGTH
-#define PICO_AUDIO_I2S_SILENCE_BUFFER_SAMPLE_LENGTH PICO_AUDIO_SILENCE_BUFFER_SAMPLE_LENGTH
-#else
-#define PICO_AUDIO_I2S_SILENCE_BUFFER_SAMPLE_LENGTH 256u
-#endif
-#endif
-
-// Allow use of pico_audio driver without actually doing anything much
-#ifndef PICO_AUDIO_I2S_NOOP
-#ifdef PICO_AUDIO_NOOP
-#define PICO_AUDIO_I2S_NOOP PICO_AUDIO_NOOP
-#else
-#define PICO_AUDIO_I2S_NOOP 0
-#endif
-#endif
-
-#ifndef PICO_AUDIO_I2S_MONO_INPUT
-#define PICO_AUDIO_I2S_MONO_INPUT 0
-#endif
-#ifndef PICO_AUDIO_I2S_MONO_OUTPUT
-#define PICO_AUDIO_I2S_MONO_OUTPUT 0
-#endif
-
-#ifndef PICO_AUDIO_I2S_DATA_PIN
-// #warning PICO_AUDIO_I2S_DATA_PIN should be defined when using AUDIO_I2S
-#define PICO_AUDIO_I2S_DATA_PIN 28
-#endif
-
-#ifndef PICO_AUDIO_I2S_CLOCK_PIN_BASE
-// #warning PICO_AUDIO_I2S_CLOCK_PIN_BASE should be defined when using AUDIO_I2S
-#define PICO_AUDIO_I2S_CLOCK_PIN_BASE 26
-#endif
-
-    /** \brief Base configuration structure used when setting up
-     * \ingroup pico_audio_i2s
-     */
-    typedef struct
-    {
-        uint32_t freq;
-        uint32_t bps;
-        uint8_t data_pin;
-        uint8_t clock_pin_base;
-
-    } audio_i2s_config_t;
-
-    typedef struct
-    {
-        uint32_t freq;
-        uint8_t pio_sm;
-        uint8_t dma_channel;
-    } shared_state_t;
-
-    typedef struct audio_format
-    {
-        uint32_t sample_freq;   ///< Sample frequency in Hz
-        uint16_t format;        ///< Audio format \ref audio_formats
-        uint16_t channel_count; ///< Number of channels
-    } audio_format_t;
-
-    /** \brief Set up system to output I2S audio
-     * \ingroup pico_audio_i2s
-     *
-     * \param intended_audio_format \todo
-     * \param config The configuration to apply.
-     */
-    void pico_i2s_setup(const audio_i2s_config_t *config);
-
-    /** \brief Set up system to output I2S audio
-     * \ingroup pico_audio_i2s
-     *
-     * \param enable true to enable I2S audio, false to disable.
-     */
-    void audio_i2s_set_enabled(bool enabled);
-
-    void audio_start_dma_transfer(const int32_t *bytes, uint32_t count);
-
-#endif
-    //----------------------------------------------------------------------------------
-    //----------------------------------------------------------------------------------
-    //----------------------------------------------------------------------------------
-    //----------------------------------------------------------------------------------
-    //----------------------------------------------------------------------------------
-
-#define AUDIO_BUFFER_FRAMES 48
-#define STEREO_BUFFER_SIZE AUDIO_BUFFER_FRAMES * 2
+#define AUDIO_BUFFER_FRAMES SIZE_OF_SAMPLES
+#define STEREO_BUFFER_SIZE AUDIO_BUFFER_FRAMES * 2 // for left + right
 
     typedef struct
     {
@@ -177,16 +34,22 @@ extern "C"
 
     typedef struct pio_i2s
     {
+        int32_t output_buffer[STEREO_BUFFER_SIZE * 2]; // double buffering, so x2
+        int32_t *out_ctrl_blocks[2];
+
         PIO pio;
         uint8_t sm_mask;
         uint8_t sm_dout;
         uint dma_ch_out_ctrl;
         uint dma_ch_out_data;
-        int32_t *out_ctrl_blocks[2];
-        int32_t output_buffer[STEREO_BUFFER_SIZE * 2];
+        int buffer_index;
+
     } pio_i2s;
 
-    void i2s_program_start_synched(PIO pio, void (*dma_handler)(void), pio_i2s *i2s, audio_i2s_config_t *config);
+    void i2s_program_setup(PIO pio, void (*dma_handler)(void), pio_i2s *i2s, const audio_i2s_config_t *config);
+
+    void i2s_start(pio_i2s *i2s);
+    void i2s_stop(pio_i2s *i2s);
 
 #ifdef __cplusplus
 }
diff --git a/software/system/audio_player.c b/software/system/audio_player.c
index 762c165..b9efeab 100644
--- a/software/system/audio_player.c
+++ b/software/system/audio_player.c
@@ -10,10 +10,8 @@
 #include "ost_hal.h"
 #include "serializers.h"
 
-#define SIZE_OF_SAMPLES (128) // in bytes
-
 // Audio Double Buffer for DMA transfer
-int32_t audio_buf[2][SIZE_OF_SAMPLES];
+int32_t audio_buf[SIZE_OF_SAMPLES];
 
 // int16_t audio_buf16[2][SIZE_OF_SAMPLES];
 // Audio Buffer for File Read
@@ -64,14 +62,10 @@ void audio_init(audio_ctx_t *ctx)
 
     for (int i = 0; i < SIZE_OF_SAMPLES; i++)
     {
-        audio_buf[0][i] = DAC_ZERO_VALUE;
-        audio_buf[1][i] = DAC_ZERO_VALUE;
-
-        // audio_buf16[0][i] = DAC_ZERO_VALUE;
-        // audio_buf16[1][i] = DAC_ZERO_VALUE;
+        audio_buf[i] = DAC_ZERO_VALUE;
     }
 
-    ctx->dma_trans_number = SIZE_OF_SAMPLES / 4;
+    ctx->transfer_size = SIZE_OF_SAMPLES / 4;
 }
 
 static int list_chunk_is_info_type(audio_ctx_t *ctx)
@@ -188,7 +182,7 @@ static int get_audio_buf(audio_ctx_t *ctx, int32_t *buf_32b)
         {
             debug_printf("ERROR: f_read %d, data_offset = %d\n\r", (int)fr, (int)ctx->audio_info.data_offset);
             f_close(&ctx->fil);
-            ctx->dma_trans_number = number / 4;
+            ctx->transfer_size = number / 4;
             return 1;
         }
         if (ctx->audio_info.data_size <= ctx->audio_info.data_offset)
@@ -232,40 +226,31 @@ static int get_audio_buf(audio_ctx_t *ctx, int32_t *buf_32b)
     */
     // ctx->audio_info.lvl_l = get_level(lvl_l / (number / 4));
     // ctx->audio_info.lvl_r = get_level(lvl_r / (number / 4));
-    ctx->dma_trans_number = (number / 4); // 32 bytes tranfers
+    ctx->transfer_size = (number / 4); // 32 bytes tranfers
     return _next_is_end;
 }
 
 int audio_process(audio_ctx_t *ctx)
 {
-    int nxt1 = (ctx->count & 0x1) ^ 0x1;
-    int nxt2 = 1 - nxt1;
-    // dma_flag_clear(DMA1, DMA_CH1, DMA_FLAG_FTF);
-    // dma_channel_disable(DMA1, DMA_CH1);
-
-    ost_hal_audio_frame_end();
-
     if (ctx->next_is_end)
     {
         ctx->playing = 0;
         ctx->pausing = 0;
     }
-    // init_dma_i2s2(audio_buf[nxt1], dma_trans_number);
-    // dma_channel_enable(DMA1, DMA_CH1);
-
-    ost_hal_audio_frame_start(audio_buf[nxt1], ctx->dma_trans_number);
 
     if (ctx->playing && !ctx->pausing)
     {
-        ctx->next_is_end = get_audio_buf(ctx, audio_buf[nxt2]);
+        // Récupération du buffer audio à partir du disque
+        ctx->next_is_end = get_audio_buf(ctx, &audio_buf[0]);
+        ost_hal_audio_new_frame(&audio_buf[0], ctx->transfer_size);
     }
     else
     {
         for (int i = 0; i < SIZE_OF_SAMPLES; i++)
         {
-            audio_buf[nxt2][i] = DAC_ZERO_VALUE;
+            audio_buf[i] = DAC_ZERO_VALUE;
         }
-        ctx->dma_trans_number = SIZE_OF_SAMPLES / 4;
+        ctx->transfer_size = SIZE_OF_SAMPLES / 4;
     }
     ctx->count++;
 
diff --git a/software/system/audio_player.h b/software/system/audio_player.h
index 3c68352..9699441 100644
--- a/software/system/audio_player.h
+++ b/software/system/audio_player.h
@@ -6,6 +6,7 @@
 
 #include <ff.h>
 
+#define SIZE_OF_SAMPLES (128) // in bytes
 #define FILENAME_MAX_SIZE 260
 
 typedef struct
@@ -29,7 +30,7 @@ typedef struct
 {
     FIL fil;
     audio_info_type_t audio_info;
-    int32_t dma_trans_number;
+    int32_t transfer_size;
     uint16_t idx_play;
     int next_is_end;
     int playing;
diff --git a/software/system/main.c b/software/system/main.c
index e2b13a7..f8314d2 100644
--- a/software/system/main.c
+++ b/software/system/main.c
@@ -120,30 +120,6 @@ void UserTask_1(void *args)
     }
 }
 
-void UserTask_2(void *args)
-{
-    static ost_event_t wake_up;
-
-    wake_up.ev = 34;
-
-    while (1)
-    {
-        for (int i = 0; i < 65500; i++)
-        {
-            for (int j = 0; j < 300; j++)
-                ;
-        }
-        debug_printf("X\n");
-        for (int i = 0; i < 65500; i++)
-        {
-            for (int j = 0; j < 100; j++)
-                ;
-        }
-
-        qor_mbox_notify(&b, (void **)&wake_up, 1);
-    }
-}
-
 // ===========================================================================================================
 // SD CARD TASK
 // ===========================================================================================================
@@ -152,6 +128,8 @@ static uint32_t AudioStack[4096];
 
 static qor_mbox_t AudioMailBox;
 
+static ost_event_t wake_up;
+
 typedef struct
 {
     uint8_t ev;
@@ -162,6 +140,8 @@ ost_audio_event_t audio_queue[10];
 // End of DMA transfer callback
 static void audio_callback(void)
 {
+    qor_mbox_notify(&b, (void **)&wake_up, QOR_MBOX_OPTION_SEND_BACK);
+    gpio_xor_mask(1 << 1);
 }
 
 void AudioTask(void *args)
@@ -169,6 +149,8 @@ void AudioTask(void *args)
     picture_show("example.bmp");
     // ost_audio_play("out2.wav");
 
+    wake_up.ev = 34;
+
     qor_mbox_init(&AudioMailBox, (void **)&audio_queue, 10);
 
     ost_audio_register_callback(audio_callback);
@@ -182,37 +164,54 @@ void AudioTask(void *args)
     while (1)
     {
 
+// Benchmark code
+#if 0
         if (onetime)
         {
             onetime = false;
 
-            gpio_put(1, 1);
             ost_audio_play("out2.wav");
-            gpio_put(1, 0);
 
             int isPlaying = 0;
             int count = 0;
             do
             {
-
+                gpio_put(1, 1);
                 isPlaying = ost_audio_process();
+                gpio_put(1, 0);
                 count++;
 
             } while (isPlaying);
             debug_printf("Packets: %d\r\n", count);
         }
+#endif
 
-        // ost_event_t *e = NULL;
-        // uint32_t res = qor_mbox_wait(&b, (void **)&e, 30);
+        ost_audio_play("out2.wav");
 
-        // if (res == QOR_MBOX_OK)
-        // {
-        // }
+        ost_event_t *e = NULL;
 
-        ost_hal_gpio_set(OST_GPIO_DEBUG_LED, 0);
-        qor_sleep(500);
-        ost_hal_gpio_set(OST_GPIO_DEBUG_LED, 1);
-        qor_sleep(500);
+        int isPlaying = 0;
+        int count = 0;
+        do
+        {
+            uint32_t res = qor_mbox_wait(&AudioMailBox, (void **)&e, 30); // On devrait recevoir un message toutes les 3ms (durée d'envoi d'un buffer I2S)
+
+            if (res == QOR_MBOX_OK)
+            {
+                isPlaying = ost_audio_process();
+            }
+
+            count++;
+
+        } while (isPlaying);
+
+        for (;;)
+        {
+            ost_hal_gpio_set(OST_GPIO_DEBUG_LED, 0);
+            qor_sleep(500);
+            ost_hal_gpio_set(OST_GPIO_DEBUG_LED, 1);
+            qor_sleep(500);
+        }
     }
 }
 
diff --git a/software/system/ost_hal.h b/software/system/ost_hal.h
index cb244fb..a46d596 100644
--- a/software/system/ost_hal.h
+++ b/software/system/ost_hal.h
@@ -107,8 +107,7 @@ extern "C"
     // ----------------------------------------------------------------------------
     // AUDIO HAL
     // ----------------------------------------------------------------------------
-    void ost_hal_audio_frame_end();
-    void ost_hal_audio_frame_start(const volatile void *, int dma_trans_number);
+    void ost_hal_audio_new_frame(const void *buffer, int size);
 
 #ifdef __cplusplus
 }
diff --git a/software/system/qor.c b/software/system/qor.c
index 7e71227..580dd35 100644
--- a/software/system/qor.c
+++ b/software/system/qor.c
@@ -221,7 +221,6 @@ void qor_create_thread(qor_tcb_t *tcb, thread_func_t task, uint32_t *stack, uint
 
     tcb->state = qor_tcb_state_active;
     tcb->wait_time = 0;
-    tcb->state = qor_tcb_state_active;
     tcb->priority = priority;
     tcb->name = name;
     tcb->next = NULL;
@@ -341,7 +340,10 @@ void qor_scheduler(void)
     }
     else if (best_sleeping != NULL)
     {
+        // On va réveiller un endormi, car son temps d'attente est dépassé (ok ou timeout, ça dépend si c'est un sleep volontaire ou attente de mailbox dépassée)
         RunPt = best_sleeping;
+        RunPt->state = qor_tcb_state_active; // devient actif
+        RunPt->ts = 0;                       // means timeout
     }
     else
     {
@@ -382,6 +384,7 @@ void qor_mbox_init(qor_mbox_t *mbox, void **msgBuffer, uint32_t maxCount)
     mbox->read = 0;
     mbox->read = 0;
     mbox->head = NULL;
+    mbox->count = 0;
 }
 
 uint32_t qor_mbox_wait(qor_mbox_t *mbox, void **msg, uint32_t wait_ms)
@@ -396,6 +399,13 @@ uint32_t qor_mbox_wait(qor_mbox_t *mbox, void **msg, uint32_t wait_ms)
             RunPt->mbox = mbox;
             mbox->head = RunPt;
             qor_sleep(wait_ms);
+
+            disable_irq();
+            if (RunPt->ts == 0)
+            {
+                enable_irq();
+                return QOR_MBOX_TIMEOUT;
+            }
         }
         else
         {
@@ -445,11 +455,12 @@ uint32_t qor_mbox_notify(qor_mbox_t *mbox, void *msg, uint32_t notifyOption)
     }
     mbox->count++;
 
-    // We warn all waiting threads that a new message is available
+    // We warn waiting thread that a new message is available
     qor_tcb_t *t = mbox->head;
     if (t != NULL)
     {
         t->wait_time = 0;
+        t->state = qor_tcb_state_active; // force wake up
     }
 
     enable_irq();
diff --git a/software/system/qor.h b/software/system/qor.h
index e622505..5196371 100644
--- a/software/system/qor.h
+++ b/software/system/qor.h
@@ -84,8 +84,9 @@ typedef struct
 } mbox_stats_t;
 
 #define QOR_MBOX_OK 1
-#define QOR_MBOX_ERROR 2
-#define QOR_MBOX_FULL 3
+#define QOR_MBOX_TIMEOUT 2
+#define QOR_MBOX_ERROR 3
+#define QOR_MBOX_FULL 4
 
 void qor_mbox_init(qor_mbox_t *mbox, void **msgBuffer, uint32_t maxCount);
 uint32_t qor_mbox_wait(qor_mbox_t *mbox, void **msg, uint32_t wait_ms);
diff --git a/software/system/qor_armv6m.s b/software/system/qor_armv6m.s
index 0d7d74a..9865201 100644
--- a/software/system/qor_armv6m.s
+++ b/software/system/qor_armv6m.s
@@ -20,46 +20,6 @@
 @   The Cortex-M0 is limited on the thumb number of instructionss
 @ the context restore is therefore a bit more complex that M3 or M4 CPU
 @  One limitation is the POP instruction that cannot access to the HI registers (registers after R7)
-@
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@       |           |
-@       -------------
-@  
-@
-@
-@
-
 
 qor_go: