I2S configuration error when running code.

Question

Good day! My code is adapted from the i2s echo example. I removed all the code regarding the button click and codec because it is not needed in my application. Below is the code. When i run the code, i get errors on configuring the Rx stream.

/*
 * Copyright (c) 2021 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/drivers/i2s.h>
#include <zephyr/drivers/gpio.h>
#include <string.h>
#include <zephyr/drivers/pwm.h>


#define I2S_RX_NODE  DT_NODELABEL(i2s_rx)

#define SAMPLE_FREQUENCY    62500
#define SAMPLE_BIT_WIDTH    32
#define BYTES_PER_SAMPLE    sizeof(int16_t)
#define NUMBER_OF_CHANNELS  2
/* Such block length provides an echo with the delay of 100 ms. */
#define SAMPLES_PER_BLOCK   ((SAMPLE_FREQUENCY / 10) * NUMBER_OF_CHANNELS)
#define INITIAL_BLOCKS      2
#define TIMEOUT             1000

// PWM DEFINES
static const struct pwm_dt_spec pwm_led0 = PWM_DT_SPEC_GET(DT_ALIAS(pwm_led0));
static const struct pwm_dt_spec pwm_led1 = PWM_DT_SPEC_GET(DT_ALIAS(pwm_led1));

#define BITCLK PWM_KHZ(4000U)
#define WORD_S PWM_HZ(62500U)

#define BLOCK_SIZE  (BYTES_PER_SAMPLE * SAMPLES_PER_BLOCK)
#define BLOCK_COUNT (INITIAL_BLOCKS + 2)
K_MEM_SLAB_DEFINE_STATIC(mem_slab, BLOCK_SIZE, BLOCK_COUNT, 4);

static int16_t echo_block[SAMPLES_PER_BLOCK];
static volatile bool echo_enabled = true;
static K_SEM_DEFINE(toggle_transfer, 1, 1);


static void process_block_data(void *mem_block, uint32_t number_of_samples)
{
	static bool clear_echo_block;

	if (echo_enabled) {
		for (int i = 0; i < number_of_samples; ++i) {
			int16_t *sample = &((int16_t *)mem_block)[i];
			*sample += echo_block[i];
			echo_block[i] = (*sample) / 2;
		}

		clear_echo_block = true;
	} else if (clear_echo_block) {
		clear_echo_block = false;
		memset(echo_block, 0, sizeof(echo_block));
	}
}

static bool configure_streams(const struct device *i2s_dev_rx,
			      const struct i2s_config *config)
{
	int ret;

	ret = i2s_configure(i2s_dev_rx, I2S_DIR_RX, config);
	if (ret < 0) {
		printk("Failed to configure RX stream: %d\n", ret);
		return false;
	}

	return true;
}

static bool prepare_transfer(const struct device *i2s_dev_rx)
{
	int ret;

	for (int i = 0; i < INITIAL_BLOCKS; ++i) {
		void *mem_block;

		ret = k_mem_slab_alloc(&mem_slab, &mem_block, K_NO_WAIT);
		if (ret < 0) {
			printk("Failed to allocate TX block %d: %d\n", i, ret);
			return false;
		}

		memset(mem_block, 0, BLOCK_SIZE);
	}

	return true;
}

static bool trigger_command(const struct device *i2s_dev_rx,
			    enum i2s_trigger_cmd cmd)
{
	int ret;

	ret = i2s_trigger(i2s_dev_rx, I2S_DIR_RX, cmd);
	if (ret < 0) {
		printk("Failed to trigger command %d on RX: %d\n", cmd, ret);
		return false;
	}

	return true;
}

int main(void)
{
	uint32_t bclk_period;
	uint32_t ws_period;
	int ret1;
	int ret2;

	printk("Starting main thread\n\r");
	printk("PWM-based blinky\n");

	if (!pwm_is_ready_dt(&pwm_led0)) {
		printk("Error: PWM device %s is not ready\n",
		       pwm_led0.dev->name);
		return 0;
	}

	if (!pwm_is_ready_dt(&pwm_led1)) {
		printk("Error: PWM device %s is not ready\n",
		       pwm_led0.dev->name);
		return 0;
	}

	/*
	 * In case the default MAX_PERIOD value cannot be set for
	 * some PWM hardware, decrease its value until it can.
	 *
	 * Keep its value at least MIN_PERIOD * 4 to make sure
	 * the sample changes frequency at least once.
	 */

	bclk_period = BITCLK;
	while (pwm_set_dt(&pwm_led0, bclk_period, bclk_period / 2U)) {
		bclk_period /= 2U;
		printk("half bclk");
	}

	ws_period = WORD_S;
	while (pwm_set_dt(&pwm_led1, ws_period, ws_period / 2U)) {
		ws_period /= 2U;
		printk("half ws");
	}

	ws_period = WORD_S;
	bclk_period = BITCLK;

	const struct device *const i2s_dev_rx = DEVICE_DT_GET(I2S_RX_NODE);
	struct i2s_config config;

	printk("I2S echo sample\n");


	if (!device_is_ready(i2s_dev_rx)) {
		printk("%s is not ready\n", i2s_dev_rx->name);
		return 0;
	}


	config.word_size = SAMPLE_BIT_WIDTH;
	config.channels = NUMBER_OF_CHANNELS;
	config.format = I2S_FMT_DATA_FORMAT_I2S;
	config.options = I2S_OPT_BIT_CLK_SLAVE | I2S_OPT_FRAME_CLK_SLAVE;
	config.frame_clk_freq = SAMPLE_FREQUENCY;
	config.mem_slab = &mem_slab;
	config.block_size = BLOCK_SIZE;
	config.timeout = TIMEOUT;
	if (!configure_streams(i2s_dev_rx, &config)) {
		return 0;
	}

	for (;;) {
		k_sem_take(&toggle_transfer, K_FOREVER);

		if (!prepare_transfer(i2s_dev_rx)) {
			return 0;
		}

		if (!trigger_command(i2s_dev_rx,
				     I2S_TRIGGER_START)) {
			return 0;
		}

		printk("Streams started\n");

		while (k_sem_take(&toggle_transfer, K_NO_WAIT) != 0) {
			void *mem_block;
			uint32_t block_size;
			int ret;

			ret = i2s_read(i2s_dev_rx, &mem_block, &block_size);
			if (ret < 0) {
				printk("Failed to read data: %d\n", ret);
				break;
			}

			process_block_data(mem_block, SAMPLES_PER_BLOCK);
		}

		if (!trigger_command(i2s_dev_rx,
				     I2S_TRIGGER_DROP)) {
			return 0;
		}

		printk("Streams stopped\n");
	}

	while (1) {
		ret1 = pwm_set_dt(&pwm_led0, bclk_period, bclk_period / 2U);
		if (ret1) {
			printk("Error %d: failed to set pulse width\n", ret1);
			return 0;
		}

		ret2 = pwm_set_dt(&pwm_led1, ws_period, ws_period / 2U);
		if (ret2) {
			printk("Error %d: failed to set pulse width\n", ret2);
			return 0;
		}
	}
}

overlay

/*
 * Copyright (c) 2021 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */

&pinctrl {

	pwm0_custom: pwm0_custom {
        group1 {
            psels = <NRF_PSEL(PWM_OUT0, 0, 3)>;
            nordic,invert;
        };
    };

    pwm0_csleep: pwm0_csleep {
        group1 {
            psels = <NRF_PSEL(PWM_OUT0, 0, 3)>;
            low-power-enable;
        };
    };
	pwm1_custom: pwm1_custom {
        group1 {
            psels = <NRF_PSEL(PWM_OUT0, 0, 28)>;
            nordic,invert;
        };
    };

    pwm1_csleep: pwm1_csleep {
        group1 {
            psels = <NRF_PSEL(PWM_OUT0, 0, 28)>;
            low-power-enable;
        };
    };
	i2s0_default_alt: i2s0_default_alt {
		group1 {
			psels = <NRF_PSEL(I2S_SDIN, 0, 29)>;
		};
	};
	i2s0_sleep: i2s0_sleep {
		group1 {
			psels = <NRF_PSEL(I2S_SDIN, 0, 29)>;             
			low-power-enable;
		};
	};
};


i2s_rx: &i2s0 {
	status = "okay";
	pinctrl-0 = <&i2s0_default_alt>;
	pinctrl-names = "default";
};

&pwm0 {
    status = "okay";
    pinctrl-0 = <&pwm0_custom>;
    pinctrl-1 = <&pwm0_csleep>;
    pinctrl-names = "default", "sleep";
};

&pwm1 {
    status = "okay";
    pinctrl-0 = <&pwm1_custom>;
    pinctrl-1 = <&pwm1_csleep>;
    pinctrl-names = "default", "sleep";
};

/{
    pwmleds {
        compatible = "pwm-leds";
        pwm_led0: pwm_led_0 {
            pwms = <&pwm0 0 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
        };
		pwm_led1: pwm_led_1 {
            pwms = <&pwm1 0 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
        };
    };
	aliases {
		pwm-led0 = &pwm_led0;
		pwm-led1 = &pwm_led1;
	
	};
};

Kenneth · Accepted Answer

Qwelectric said: How does those return values translate to the numbers printed. Usual errors are -5 and -11 which is not listed there. I think my other questions were answered except for this: 
 Check out for instance \zephyr\lib\libc\minimal\include\errno.h 
 Qwelectric said: **Last question, how can I extract the audio data from the i2s memory to send it to another device using BLE?** 
 Using i2s_read() seems to be solving this? Next step I assume is possible split this data into chunks of data you then can transmit using for instance notifications. Seems like a new devzone case. 
 Kenneth

I2S configuration error when running code.

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