I2S Input DMA setup

[dawime]

Hello - I am trying to interface a mems I2C microphone to I2S0 - I have verified that the device is clocking and outputing data - The idea is to setup DMA buffers, to trigger an interrupt when DMA is complete, from the DMA ISR signal a task that will read out the last buffer, process it and notify other consumers for that data.

My problem seems to be that the DMA ISR is not getting set. I checked that the semaphores are setup properly, but I can't quite figure it out. Here is the code:

Code: [Select all] [Expand/Collapse]

1.  
2. static int16_t dma_buf[DMA_BUF_COUNT][DMA_BUF_LEN];
3. static int buf_ptr = 0;
4. SemaphoreHandle_t i2s_dma_sem;
5. static intr_handle_t i2s_isr_ret_handle;
6.  
7. void IRAM_ATTR i2s_isr_handler(void *arg)
8. {
9.     BaseType_t xHigherPriorityTaskWoken = pdFALSE;
10.  
11.     xSemaphoreGiveFromISR(i2s_dma_sem, &xHigherPriorityTaskWoken);
12.     if (xHigherPriorityTaskWoken) {
13.         portYIELD_FROM_ISR();
14.     }
15. }
16.  
17.  
18. void mic_task(void *arg)
19. {
20.     size_t bytesRead;
21.     color_t sample_colors[6] = { red, green, blue, yellow, purple, silver };
22.     printf("mic_task enabled\n\r");
23.     while (1)
24.     {
25.         if (xSemaphoreTake(i2s_dma_sem, portMAX_DELAY) == pdTRUE) {
26.             // Process the data in dma_buf[buf_ptr]
27.             // ...
28.             i2s_read(I2S_NUM, (void *)&dma_buf[buf_ptr], DMA_BUF_LEN * sizeof(int16_t), &bytesRead, 0);
29.             buf_ptr = (buf_ptr + 1) % DMA_BUF_COUNT;
30.             printf("Read %d bytes",bytesRead);
31.            
32.             // Signal the main application that new data is available
33.             // ...
34.         }
35.     }
36. }
37.  
38. void mic_init()
39. {
40.     i2s_config_t i2s_config = {
41.         .mode = I2S_MODE_MASTER | I2S_MODE_RX,
42.         .sample_rate = 44100,
43.         .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
44.         .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
45.         .communication_format = I2S_COMM_FORMAT_I2S_MSB,
46.         .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
47.         .dma_buf_count = DMA_BUF_COUNT,
48.         .dma_buf_len = DMA_BUF_LEN,
49.         .use_apll = false,
50.         .tx_desc_auto_clear = false,
51.         .fixed_mclk = 0,
52.        
53.  
54.     };
55.     i2s_driver_install(I2S_NUM, &i2s_config, 0, NULL);
56.     i2s_set_clk(I2S_NUM, 44100, I2S_BITS_PER_SAMPLE_16BIT, I2S_CHANNEL_MONO);
57.     i2s_pin_config_t pin_config = {
58.         .mck_io_num = I2S_PIN_NO_CHANGE,
59.         .bck_io_num = 3,
60.         .ws_io_num = I2S_PIN_NO_CHANGE,
61.         .data_out_num = I2S_PIN_NO_CHANGE,
62.         .data_in_num = 8
63.     };
64.     i2s_set_pin(I2S_NUM, &pin_config);
65.     i2s_zero_dma_buffer(I2S_NUM);
66.    
67.     i2s_dma_sem = xSemaphoreCreateBinary();
68.     esp_err_t err =esp_intr_alloc(ETS_I2S0_INTR_SOURCE, ESP_INTR_FLAG_LEVEL1 | ESP_INTR_FLAG_IRAM, i2s_isr_handler, NULL, &i2s_isr_ret_handle);
69.     if (err != ESP_OK)
70.         ESP_LOGE(TAG, "Error esp_intr_alloc %s", esp_err_to_name(err));
71.  
72.    
73.     err = esp_intr_enable(i2s_isr_ret_handle);
74.     ESP_LOGI(TAG, "INTERRUPT Enable:      %d ", err);
75.     xTaskCreate(mic_task, "mic_task", 4096, NULL, 5, NULL);
76.  
77. }

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Any ideas why i2s_isr_handler does not get called? Both esp_intr_alloc() and esp_intr_enable() return ESP_OK.

Thank you

[ESP_Sprite]

You cannot use both the driver as well as install your own ISR, and in your particular case, you don't need to. i2s_read() already suspends the calling task until the i2s peripheral has data available (that's why the driver needs the interrupt, it uses that to unblock the task calling i2s_read).

[dawime]

Thank you - I couldn't locate any documentation on it, but it makes sense. If the read will be blocking already, then I can forgo my interrupt and just running it on my thread directly.