My UART transmit and receive functionality is working correctly. I used STM32CubeMX to configure the UART and generate the initialization code. After testing it with a serial terminal, I was able to successfully send and receive data.
You don’t need DS1307 RTC.
I want to interface the DS1307 because it's the only I2C device I currently have. If I can successfully read and write to the DS1307, I'll know that my I2C hardware connections and communication are working correctly. That's the main reason I want to use it.
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HAL_StatusTypeDef HAL_I2C_Mem_Write_IT(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint16_t MemAddress,
uint16_t MemAddSize, uint8_t *pData, uint16_t Size)
HAL_StatusTypeDef HAL_I2C_Mem_Read_IT(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint16_t MemAddress,
uint16_t MemAddSize, uint8_t *pData, uint16_t Size)/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2026 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_host.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* 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 */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;
I2S_HandleTypeDef hi2s3;
SPI_HandleTypeDef hspi1;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);
static void MX_I2S3_Init(void);
static void MX_SPI1_Init(void);
void MX_USB_HOST_Process(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_I2C1_Init();
MX_I2S3_Init();
MX_SPI1_Init();
MX_USB_HOST_Init();
/* USER CODE BEGIN 2 */
HAL_StatusTypeDef status;
status = HAL_I2C_IsDeviceReady(&hi2c1, (0x68 << 1), 3, 100);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
//MX_USB_HOST_Process();
/* USER CODE BEGIN 3 */
if (status == HAL_OK)
{
/* DS1307 acknowledged its address */
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET); // Green LED ON
}
else
{
/* DS1307 did not acknowledge */
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_14, GPIO_PIN_SET); // Red LED ON
}
}
/* 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 = 8;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 7;
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_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief I2C1 Initialization Function
* @param None
* @retval None
*/
static void MX_I2C1_Init(void)
{
/* USER CODE BEGIN I2C1_Init 0 */
/* USER CODE END I2C1_Init 0 */
/* USER CODE BEGIN I2C1_Init 1 */
/* USER CODE END I2C1_Init 1 */
hi2c1.Instance = I2C1;
hi2c1.Init.ClockSpeed = 100000;
hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
hi2c1.Init.OwnAddress1 = 0;
hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c1.Init.OwnAddress2 = 0;
hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2C1_Init 2 */
/* USER CODE END I2C1_Init 2 */
}
/**
* @brief I2S3 Initialization Function
* @param None
* @retval None
*/
static void MX_I2S3_Init(void)
{
/* USER CODE BEGIN I2S3_Init 0 */
/* USER CODE END I2S3_Init 0 */
/* USER CODE BEGIN I2S3_Init 1 */
/* USER CODE END I2S3_Init 1 */
hi2s3.Instance = SPI3;
hi2s3.Init.Mode = I2S_MODE_MASTER_TX;
hi2s3.Init.Standard = I2S_STANDARD_PHILIPS;
hi2s3.Init.DataFormat = I2S_DATAFORMAT_16B;
hi2s3.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;
hi2s3.Init.AudioFreq = I2S_AUDIOFREQ_96K;
hi2s3.Init.CPOL = I2S_CPOL_LOW;
hi2s3.Init.ClockSource = I2S_CLOCK_PLL;
hi2s3.Init.FullDuplexMode = I2S_FULLDUPLEXMODE_DISABLE;
if (HAL_I2S_Init(&hi2s3) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2S3_Init 2 */
/* USER CODE END I2S3_Init 2 */
}
/**
* @brief SPI1 Initialization Function
* @param None
* @retval None
*/
static void MX_SPI1_Init(void)
{
/* USER CODE BEGIN SPI1_Init 0 */
/* USER CODE END SPI1_Init 0 */
/* USER CODE BEGIN SPI1_Init 1 */
/* USER CODE END SPI1_Init 1 */
/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 10;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN SPI1_Init 2 */
/* USER CODE END SPI1_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOE_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(CS_I2C_SPI_GPIO_Port, CS_I2C_SPI_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(OTG_FS_PowerSwitchOn_GPIO_Port, OTG_FS_PowerSwitchOn_Pin, GPIO_PIN_SET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOD, LD4_Pin|LD3_Pin|LD5_Pin|LD6_Pin
|Audio_RST_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin : CS_I2C_SPI_Pin */
GPIO_InitStruct.Pin = CS_I2C_SPI_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(CS_I2C_SPI_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : OTG_FS_PowerSwitchOn_Pin */
GPIO_InitStruct.Pin = OTG_FS_PowerSwitchOn_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(OTG_FS_PowerSwitchOn_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : PDM_OUT_Pin */
GPIO_InitStruct.Pin = PDM_OUT_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
HAL_GPIO_Init(PDM_OUT_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : B1_Pin */
GPIO_InitStruct.Pin = B1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_EVT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : BOOT1_Pin */
GPIO_InitStruct.Pin = BOOT1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(BOOT1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : CLK_IN_Pin */
GPIO_InitStruct.Pin = CLK_IN_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
HAL_GPIO_Init(CLK_IN_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pins : LD4_Pin LD3_Pin LD5_Pin LD6_Pin
Audio_RST_Pin */
GPIO_InitStruct.Pin = LD4_Pin|LD3_Pin|LD5_Pin|LD6_Pin
|Audio_RST_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
/*Configure GPIO pin : OTG_FS_OverCurrent_Pin */
GPIO_InitStruct.Pin = OTG_FS_OverCurrent_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(OTG_FS_OverCurrent_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : MEMS_INT2_Pin */
GPIO_InitStruct.Pin = MEMS_INT2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_EVT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(MEMS_INT2_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
/* 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 *//* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2026 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_host.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* 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 */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;
I2S_HandleTypeDef hi2s3;
SPI_HandleTypeDef hspi1;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);
static void MX_I2S3_Init(void);
static void MX_SPI1_Init(void);
void MX_USB_HOST_Process(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_I2C1_Init();
MX_I2S3_Init();
MX_SPI1_Init();
MX_USB_HOST_Init();
/* USER CODE BEGIN 2 */
HAL_StatusTypeDef status;
status = HAL_I2C_IsDeviceReady(&hi2c1, (0x68 << 1), 3, 100);
HAL_Delay(1000);
if (status == HAL_OK)
{
/* DS1307 acknowledged its address */
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET); // Green LED ON
}
else
{
/* DS1307 did not acknowledge */
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_14, GPIO_PIN_SET); // Red LED ON
}
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
//MX_USB_HOST_Process();
/* USER CODE BEGIN 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 = 8;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 7;
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_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief I2C1 Initialization Function
* @param None
* @retval None
*/
static void MX_I2C1_Init(void)
{
/* USER CODE BEGIN I2C1_Init 0 */
/* USER CODE END I2C1_Init 0 */
/* USER CODE BEGIN I2C1_Init 1 */
/* USER CODE END I2C1_Init 1 */
hi2c1.Instance = I2C1;
hi2c1.Init.ClockSpeed = 100000;
hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
hi2c1.Init.OwnAddress1 = 0;
hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c1.Init.OwnAddress2 = 0;
hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2C1_Init 2 */
/* USER CODE END I2C1_Init 2 */
}
/**
* @brief I2S3 Initialization Function
* @param None
* @retval None
*/
static void MX_I2S3_Init(void)
{
/* USER CODE BEGIN I2S3_Init 0 */
/* USER CODE END I2S3_Init 0 */
/* USER CODE BEGIN I2S3_Init 1 */
/* USER CODE END I2S3_Init 1 */
hi2s3.Instance = SPI3;
hi2s3.Init.Mode = I2S_MODE_MASTER_TX;
hi2s3.Init.Standard = I2S_STANDARD_PHILIPS;
hi2s3.Init.DataFormat = I2S_DATAFORMAT_16B;
hi2s3.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;
hi2s3.Init.AudioFreq = I2S_AUDIOFREQ_96K;
hi2s3.Init.CPOL = I2S_CPOL_LOW;
hi2s3.Init.ClockSource = I2S_CLOCK_PLL;
hi2s3.Init.FullDuplexMode = I2S_FULLDUPLEXMODE_DISABLE;
if (HAL_I2S_Init(&hi2s3) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2S3_Init 2 */
/* USER CODE END I2S3_Init 2 */
}
/**
* @brief SPI1 Initialization Function
* @param None
* @retval None
*/
static void MX_SPI1_Init(void)
{
/* USER CODE BEGIN SPI1_Init 0 */
/* USER CODE END SPI1_Init 0 */
/* USER CODE BEGIN SPI1_Init 1 */
/* USER CODE END SPI1_Init 1 */
/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 10;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN SPI1_Init 2 */
/* USER CODE END SPI1_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOE_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(CS_I2C_SPI_GPIO_Port, CS_I2C_SPI_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(OTG_FS_PowerSwitchOn_GPIO_Port, OTG_FS_PowerSwitchOn_Pin, GPIO_PIN_SET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOD, LD4_Pin|LD3_Pin|LD5_Pin|LD6_Pin
|Audio_RST_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin : CS_I2C_SPI_Pin */
GPIO_InitStruct.Pin = CS_I2C_SPI_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(CS_I2C_SPI_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : OTG_FS_PowerSwitchOn_Pin */
GPIO_InitStruct.Pin = OTG_FS_PowerSwitchOn_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(OTG_FS_PowerSwitchOn_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : PDM_OUT_Pin */
GPIO_InitStruct.Pin = PDM_OUT_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
HAL_GPIO_Init(PDM_OUT_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : B1_Pin */
GPIO_InitStruct.Pin = B1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_EVT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : BOOT1_Pin */
GPIO_InitStruct.Pin = BOOT1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(BOOT1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : CLK_IN_Pin */
GPIO_InitStruct.Pin = CLK_IN_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
HAL_GPIO_Init(CLK_IN_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pins : LD4_Pin LD3_Pin LD5_Pin LD6_Pin
Audio_RST_Pin */
GPIO_InitStruct.Pin = LD4_Pin|LD3_Pin|LD5_Pin|LD6_Pin
|Audio_RST_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
/*Configure GPIO pin : OTG_FS_OverCurrent_Pin */
GPIO_InitStruct.Pin = OTG_FS_OverCurrent_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(OTG_FS_OverCurrent_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : MEMS_INT2_Pin */
GPIO_InitStruct.Pin = MEMS_INT2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_EVT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(MEMS_INT2_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
/* 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 */How do you confirm whether the issue is with the hardware rather than the firmware? Have you tested this yourself with an STM32 and a DS1307 using a similar setup? Also, do you have the same hardware configuration? What's your experience working with STM32 and I2C, and whether you've successfully interfaced a DS1307 before.
Have you asked AI (Copilot)? I have done a lot with STM32 and had good results when getting guidance from AI recently. I hadn't used AI at all but a few months ago had challenges when working with this device - nRF24L01P (SPI) - AI was instrumental in getting it all working cleanly.
I've tried, but I haven't had any luck resolving this particular issue.
Sorry, I don't have any I2C. Have you looked at STM32 I2C examples?
Yes, I'm trying different STM32 I2C examples to rule out a software issue. I don't have an oscilloscope, but I do have a logic analyzer. When I capture the I2C bus, both SDA and SCL remain flat there are no START condition, clock pulses, or data transitions. That makes me think the I2C peripheral may not be generating any signals, so the issue could be with the I2C configuration or initialization rather than communication with the DS1307
Peripherals each have clock enable/disable (a power saving feature). A common error is failing to enable the peripheral's clock, that often has symptoms like yours.
