Hi!
I'm trying to get an SPH0645 microphone to send sound data to my STM32F411 with HAL_I2S_Receive(), but the data I receive is not correct. According to the data sheet, the microphone gives 24 bits data on a 32 bit frame, with 24 bits containing data and the rest being filled with zeroes, which I confirmed by looking on my oscilloscope: (yellow is data, blue is word select and purple is clock)
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2023 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usb_device.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdlib.h>
#include <stdbool.h>
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
#define BUFFER_SIZE 64
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
I2S_HandleTypeDef hi2s1;
/* USER CODE BEGIN PV */
uint16_t i2s_data[BUFFER_SIZE];
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2S1_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USB_DEVICE_Init();
MX_I2S1_Init();
/* USER CODE BEGIN 2 */
HAL_StatusTypeDef result = HAL_I2S_Receive(&hi2s1, i2s_data, BUFFER_SIZE/2, 100);
if(result != HAL_OK){
printf("HAL_I2S_Receive error code: %d\n", result);
}
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
for(int i = 0; i < BUFFER_SIZE; i++){
printf("i2s_data[%d] = %d\n", i, i2s_data[i]);
HAL_Delay(3);
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 25;
RCC_OscInitStruct.PLL.PLLN = 192;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 4;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief I2S1 Initialization Function
* @param None
* @retval None
*/
static void MX_I2S1_Init(void)
{
/* USER CODE BEGIN I2S1_Init 0 */
/* USER CODE END I2S1_Init 0 */
/* USER CODE BEGIN I2S1_Init 1 */
/* USER CODE END I2S1_Init 1 */
hi2s1.Instance = SPI1;
hi2s1.Init.Mode = I2S_MODE_MASTER_RX;
hi2s1.Init.Standard = I2S_STANDARD_PHILIPS;
hi2s1.Init.DataFormat = I2S_DATAFORMAT_24B;
hi2s1.Init.MCLKOutput = I2S_MCLKOUTPUT_DISABLE;
hi2s1.Init.AudioFreq = I2S_AUDIOFREQ_48K;
hi2s1.Init.CPOL = I2S_CPOL_LOW;
hi2s1.Init.ClockSource = I2S_CLOCK_PLL;
hi2s1.Init.FullDuplexMode = I2S_FULLDUPLEXMODE_DISABLE;
if (HAL_I2S_Init(&hi2s1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2S1_Init 2 */
/* USER CODE END I2S1_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_9, GPIO_PIN_RESET);
/*Configure GPIO pin : PC13 */
GPIO_InitStruct.Pin = GPIO_PIN_13;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/*Configure GPIO pin : PA9 */
GPIO_InitStruct.Pin = GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}
/* USER CODE BEGIN 4 */
int _write(int file, char *ptr, int len) {
CDC_Transmit_FS((uint8_t*) ptr, len);
return len;
}
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */The data I receive from this code looks like this:
i2s_data[0] = 0
...
i2s_data[26] = 0
i2s_data[27] = 0
i2s_data[28] = 6627
i2s_data[29] = 32769
i2s_data[30] = 0
i2s_data[31] = 0
i2s_data[32] = 64042
i2s_data[33] = 49152
i2s_data[34] = 0
i2s_data[35] = 0
i2s_data[36] = 64018
i2s_data[37] = 49152
i2s_data[38] = 0
i2s_data[39] = 0
i2s_data[40] = 64006
i2s_data[41] = 16384
i2s_data[42] = 0
i2s_data[43] = 0
i2s_data[44] = 64000
i2s_data[45] = 16385
i2s_data[46] = 0
i2s_data[47] = 0
i2s_data[48] = 63996
i2s_data[49] = 32768
i2s_data[50] = 0
i2s_data[51] = 0
i2s_data[52] = 63994
i2s_data[53] = 16384
i2s_data[54] = 0
i2s_data[55] = 0
i2s_data[56] = 63992
i2s_data[57] = 32768
i2s_data[58] = 0
i2s_data[59] = 0
i2s_data[60] = 63990
i2s_data[61] = 1
i2s_data[62] = 0
i2s_data[63] = 0It takes a little while for the microphone to start, (only zeroes) but after a while you start to see the data from the left channel coming in when the word select voltage is low. (as expected)
But the data is not correct. There's a suspicious amount of values being exactly 16385 between different runs for some reason, and the last 8 bits are not zeroes as the datasheet says. (for example with 16385 being 0100000000000001 in binary)
In the CubeIDE GUI I selected the following settings:
Any ideas to what the problem could be?
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