If it's important, this is my code:
#include "main.h"
I2S_HandleTypeDef hi2s2;
I2S_HandleTypeDef hi2s3;
DMA_HandleTypeDef hdma_spi2_rx;
DMA_HandleTypeDef hdma_spi3_tx;
uint16_t rxBuf[AUDIO_BUFFER_LENGTH];
uint16_t txBuf[AUDIO_BUFFER_LENGTH];
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_I2S2_Init(void);
static void MX_I2S3_Init(void);
int main(void)
{
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_I2S3_Init();
MX_I2S2_Init();
HAL_I2S_Transmit_DMA(&hi2s3, (uint16_t*)&txBuf, AUDIO_BUFFER_16BIT_LENGTH);
HAL_I2S_Receive_DMA(&hi2s2, (uint16_t*)&rxBuf, AUDIO_BUFFER_16BIT_LENGTH);
while (1)
{
}
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
/** Initializes the CPU, AHB and APB busses clocks
*/
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 = 4;
RCC_OscInitStruct.PLL.PLLN = 168;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 2;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB busses 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_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_I2S;
PeriphClkInitStruct.PLLI2S.PLLI2SN = 96;
PeriphClkInitStruct.PLLI2S.PLLI2SP = RCC_PLLP_DIV2;
PeriphClkInitStruct.PLLI2S.PLLI2SR = 2;
PeriphClkInitStruct.PLLI2S.PLLI2SQ = 2;
PeriphClkInitStruct.PLLI2SDivQ = 1;
PeriphClkInitStruct.I2sClockSelection = RCC_I2SCLKSOURCE_PLLI2S;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief I2S2 Initialization Function
* @param None
* @retval None
*/
static void MX_I2S2_Init(void)
{
hi2s2.Instance = SPI2;
hi2s2.Init.Mode = I2S_MODE_MASTER_RX;
hi2s2.Init.Standard = I2S_STANDARD_PHILIPS;
hi2s2.Init.DataFormat = I2S_DATAFORMAT;
hi2s2.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;
hi2s2.Init.AudioFreq = I2S_SAMPLE_RATE;
hi2s2.Init.CPOL = I2S_CPOL_LOW;
hi2s2.Init.ClockSource = I2S_CLOCK_PLL;
if (HAL_I2S_Init(&hi2s2) != HAL_OK)
{
Error_Handler();
}
}
/**
* @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_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOE_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
}
/**
* @brief I2S3 Initialization Function
* @param None
* @retval None
*/
static void MX_I2S3_Init(void)
{
hi2s3.Instance = SPI3;
hi2s3.Init.Mode = I2S_MODE_SLAVE_TX;
hi2s3.Init.Standard = I2S_STANDARD_PHILIPS;
hi2s3.Init.DataFormat = I2S_DATAFORMAT;
hi2s3.Init.MCLKOutput = I2S_MCLKOUTPUT_DISABLE;
hi2s3.Init.AudioFreq = I2S_SAMPLE_RATE;
hi2s3.Init.CPOL = I2S_CPOL_LOW;
hi2s3.Init.ClockSource = I2S_CLOCK_PLL;
if (HAL_I2S_Init(&hi2s3) != HAL_OK)
{
Error_Handler();
}
}
/**
* Enable DMA controller clock
*/
static void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Stream1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 1, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);
/* DMA1_Stream5_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 1, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);
}
void HAL_I2S_RxHalfCpltCallback(I2S_HandleTypeDef *hi2s) {
ARM_COPY((Q*)&rxBuf, (Q*)&txBuf, AUDIO_BUFFER_LENGTH>>1);
}
void HAL_I2S_TxHalfCpltCallback(I2S_HandleTypeDef *hi2s) {
}
void HAL_I2S_RxCpltCallback(I2S_HandleTypeDef *hi2s) {
ARM_COPY((Q*)&rxBuf[AUDIO_BUFFER_LENGTH>>1], (Q*)&txBuf[AUDIO_BUFFER_LENGTH>>1], AUDIO_BUFFER_LENGTH>>1);
}
void HAL_I2S_TxCpltCallback(I2S_HandleTypeDef *hi2s) {
}
Definitions of custom macros are in two separate files:
i2s_audio_settings.h
#ifndef I2S_AUDIO_SETTINGS_H
#define I2S_AUDIO_SETTINGS_H
#include "stm32f7xx_hal.h"
#define NUM_CHANNELS 2
#define AUDIO_DATA_SIZE 16
#define AUDIO_SAMPLE_RATE 44
#define AUDIO_BUFFER_SAMPLES_PER_CHANNEL 16
#if AUDIO_DATA_SIZE == 24
#define I2S_DATAFORMAT I2S_DATAFORMAT_24B
#define AUDIO_BUFFER_T int32_t
#define AUDIO_BUFFER_16BIT_LENGTH AUDIO_BUFFER_SAMPLES_PER_CHANNEL << (NUM_CHANNELS)
#define AUDIO_BUFFER_LENGTH AUDIO_BUFFER_16BIT_LENGTH >> 1 // should treat lenght as int32
#else
#define I2S_DATAFORMAT I2S_DATAFORMAT_16B
#define AUDIO_BUFFER_T int16_t
#define AUDIO_BUFFER_16BIT_LENGTH AUDIO_BUFFER_SAMPLES_PER_CHANNEL << (NUM_CHANNELS - 1)
#define AUDIO_BUFFER_LENGTH AUDIO_BUFFER_16BIT_LENGTH
#endif
#define AUDIO_BUFFER_PTR_T AUDIO_BUFFER_T*
// TODO: extend
#if AUDIO_SAMPLE_RATE == 44
#define I2S_SAMPLE_RATE I2S_AUDIOFREQ_44K
#else
#define I2S_SAMPLE_RATE I2S_AUDIOFREQ_96K
#endif
#endif
dsp.h
#ifndef __DSP_H
#define __DSP_H
#define ARM_MATH_CM7
#include <stdio.h>
#include <stdlib.h>
#include "arm_math.h"
#include "i2s_audio_settings.h"
#if AUDIO_DATA_SIZE > 16
#define UINT uint32_t
#define Q q31_t
#define ARM_RFFT_INSTANCE arm_rfft_instance_q31
#define ARM_CFFT_RADIX4_INSTANCE arm_cfft_radix4_instance_q31
#define ARM_COPY(in, out, size) arm_copy_q31(in, out, size)
#define ARM_RFFT_INIT(rfftInstancePtr, size) arm_rfft_init_q31(rfftInstancePtr, size, 0, 1)
#define ARM_RFFT(instance, in, out) arm_rfft_q31(instance, in, out)
#define ARM_SHIFT(in, shift, out, size) arm_shift_q31(in, shift, out, size)
#else
#define UINT uint16_t
#define Q q15_t
#define ARM_RFFT_INSTANCE arm_rfft_instance_q15
#define ARM_CFFT_RADIX4_INSTANCE arm_cfft_radix4_instance_q15
#define ARM_COPY(in, out, size) arm_copy_q15(in, out, size)
#define ARM_RFFT_INIT(rfftInstancePtr, size) arm_rfft_init_q15(rfftInstancePtr, size, 0, 1)
#define ARM_RFFT(instance, in, out) arm_rfft_q15(instance, in, out)
#define ARM_SHIFT(in, shift, out, size) arm_shift_q15(in, shift, out, size)
#endif
#endif
