2025-06-18 11:57 PM - edited 2025-06-19 12:00 AM
I have been trying to configure Nucleo STM32F401RE board as an I2C Slave and Xavier Nx as Master but it is throwing me BUSERR.
I am adding some the main.c file below to explain my configuration
main.c
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2025 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 "i2c.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
#include <string.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 */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
uint8_t i2c_rx_buff[10];
uint8_t i2c_tx_buff[4] = {0xAA,0xBB,0xCC, 0xDD};
volatile bool i2c_rx_done = false;
//volatile bool i2c_tx_done = false;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(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();
/* USER CODE BEGIN 2 */
HAL_I2C_EnableListen_IT(&hi2c1);
__enable_irq();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
if(i2c_rx_done)
{
i2c_rx_done = false;
}
/* USER CODE END WHILE */
/* 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};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
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_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
void HAL_I2C_AddrCallback(I2C_HandleTypeDef *hi2c, uint8_t TransferDirection, uint16_t AddrMatchCode)
{
if(hi2c->Instance == I2C1)
{
if(TransferDirection == I2C_DIRECTION_TRANSMIT)
{
HAL_I2C_Slave_Sequential_Receive_IT(hi2c, i2c_rx_buff, sizeof(i2c_rx_buff), I2C_FIRST_AND_LAST_FRAME);
}
else if(TransferDirection == I2C_DIRECTION_RECEIVE)
{
HAL_I2C_Slave_Transmit_IT(hi2c, i2c_tx_buff, sizeof(i2c_tx_buff));
}
else{
Error_Handler();
}
}
}
void HAL_I2C_ListenCpltCallback(I2C_HandleTypeDef *hi2c)
{
HAL_I2C_EnableListen_IT(hi2c);
}
void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *hi2c)
{
i2c_rx_done = true;
}
/* 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 */
i2c.c // added only functions
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 = 0x30;
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 */
}
void HAL_I2C_MspInit(I2C_HandleTypeDef* i2cHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(i2cHandle->Instance==I2C1)
{
/* USER CODE BEGIN I2C1_MspInit 0 */
/* USER CODE END I2C1_MspInit 0 */
__HAL_RCC_GPIOB_CLK_ENABLE();
/**I2C1 GPIO Configuration
PB8 ------> I2C1_SCL
PB9 ------> I2C1_SDA
*/
GPIO_InitStruct.Pin = GPIO_PIN_8;
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF4_I2C1;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF4_I2C1;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* I2C1 clock enable */
__HAL_RCC_I2C1_CLK_ENABLE();
/* USER CODE BEGIN I2C1_MspInit 1 */
/* USER CODE END I2C1_MspInit 1 */
}
}
On Xavier:
1) sudo i2cdetect -y 1
o/p: 30 -- -- -- ...
2) sudo i2cset -y 1 0x30 0xAA 0xBB i
o/p: Write failed
What am I doing wrong to get a BUSERR
2025-06-19 8:40 AM
Hello,
can you also share a hardware connection? Are there connected external pull up resistors?
To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
2025-06-19 9:02 AM
It looks like you have internal pull-up enabled for SCL, but not for SDA. Hopefully you're not relying on internal pull-ups and that you indeed have external pull-ups. If not, use 2 resistors on both SCL and SDA. ~4.7K is typical value to start with.