ESP32 I2S not working

[unreal widget]

I'm using an ESP32 Wroom32 S3, i've been trying to get the I2S bus working in ESPIDF 5.5 to some of my gpio pins as fast parallel outputs. What is going on? Am I architecturally getting something wrong?

static esp_lcd_i80_bus_handle_t i80_bus = nullptr;
static esp_lcd_panel_io_handle_t io_handle = nullptr;

uint8_t pattern_over_time[] = {
    0b11111100,  // pad 2 LSBs for 8-bit alignment
    0b00000000,
    0b11111100,
    0b00000000
};
const size_t pattern_len = sizeof(pattern_over_time);

void setup_i80() {
    esp_lcd_i80_bus_config_t bus_config = {};
    bus_config.wr_gpio_num = (gpio_num_t)PIN_WR;
    bus_config.dc_gpio_num = (gpio_num_t)PIN_DC;
    bus_config.data_gpio_nums[0] = PIN_D0;
    bus_config.data_gpio_nums[1] = PIN_D1;
    bus_config.data_gpio_nums[2] = PIN_D2;
    bus_config.data_gpio_nums[3] = PIN_D3;
    bus_config.data_gpio_nums[4] = PIN_D4;
    bus_config.data_gpio_nums[5] = PIN_D5;
    bus_config.data_gpio_nums[6] = GPIO_NUM_NC; // NC pins for 8-bit width
    bus_config.data_gpio_nums[7] = GPIO_NUM_NC;
    bus_config.bus_width = 8;                   // Must be 8 for DMA to work
    bus_config.clk_src = LCD_CLK_SRC_PLL160M;
    bus_config.max_transfer_bytes = 4096;
    ESP_ERROR_CHECK(esp_lcd_new_i80_bus(&bus_config, &i80_bus));

    esp_lcd_panel_io_i80_config_t io_config = {};
    io_config.cs_gpio_num = GPIO_NUM_NC;
    io_config.pclk_hz = 2000000;  // 2 MHz for scope
    io_config.trans_queue_depth = 2;
    io_config.lcd_cmd_bits = 8;
    io_config.lcd_param_bits = 8;
    ESP_ERROR_CHECK(esp_lcd_new_panel_io_i80(i80_bus, &io_config, &io_handle));
}

void write_pattern() {
    // DMA works now because bus width is 8
    ESP_ERROR_CHECK(esp_lcd_panel_io_tx_param(io_handle, 0, pattern_over_time, pattern_len));
}

extern "C" void app_main() {
    setup_i80();

    while (1) {
        write_pattern();
        vTaskDelay(pdMS_TO_TICKS(200));  // small delay for DMA
    }
}

my defines and headers cause i ran out of words:

#include "driver/gpio.h"
#include "esp_lcd_panel_io.h"
#include "esp_lcd_io_i80.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#define PIN_D0 7
#define PIN_D1 15
#define PIN_D2 16
#define PIN_D3 17
#define PIN_D4 18
#define PIN_D5 8
#define PIN_WR 37
#define PIN_DC 21  // must be a valid pin

[torpid warren]

What's the issue exactly?

[unreal widget]

Idk how to properly initialise the i2s dma lanes and send data through them

[torpid warren]

Did you check the official IDF examples?

That's generally what I do

And read the doc, it gives you a good overview https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/i2s.html

And there are other tutorials https://dronebotworkshop.com/esp32-i2s/

Once you have some minimal code setup you can come back to ask if there's an issue

[unreal widget]

I'll give it a look see and ping reply if i get more issues :3

[proven solar]

@unreal widget has reached level 1. GG!

[unreal widget]

Using espidf 5.5 i could not get the i2s to work, the documentation on the official website is not updating it seems as i2s_std isnt available for the newer libraries

it says i2s.h provides legacy api access, however it doesnt seem to be available

[torpid warren]

You can't include the i2s headers?

[unreal widget]

I managed to get it working, turns out the issue wasnt the i2s directly, it was the dma transfer

should i close this forum or leave it open?

[torpid warren]

whatever you want

[unreal widget]

ill post my solution here incase of travellers of the coding seas