Using Nucleo-L476RG board with I2C. Using a logic analyzer i'm getting meaningless signals as seen in the image. SDA AND SCL are connected to pins PB11 and PB10 respectively and are connected directly to the logic analyzer block directly to monitor them. This pattern happens regardless of whether transmitting, receiving or idle. When zooming each pulse is a spike around 25ns and isnt related to anything.
I2C Init:
static void MX_I2C2_Init(void)
{
/* USER CODE BEGIN I2C2_Init 0 */
/* USER CODE END I2C2_Init 0 */
/* USER CODE BEGIN I2C2_Init 1 */
/* USER CODE END I2C2_Init 1 */
hi2c2.Instance = I2C2;
hi2c2.Init.Timing = 0x1060669A ;
hi2c2.Init.OwnAddress1 = 0;
hi2c2.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c2.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c2.Init.OwnAddress2 = 0;
hi2c2.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
hi2c2.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c2.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c2) != HAL_OK)
{
Error_Handler();
}
/** Configure Analogue filter
*/
if (HAL_I2CEx_ConfigAnalogFilter(&hi2c2, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
{
Error_Handler();
}
/** Configure Digital filter
*/
if (HAL_I2CEx_ConfigDigitalFilter(&hi2c2, 0) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2C2_Init 2 */
/* USER CODE END I2C2_Init 2 */
}Transmitting code:
short SCCB_Write(uint8_t reg_addr, uint8_t data) {
short opertionStatus = 0;
uint8_t buffer[2] = { 0 };
HAL_StatusTypeDef connectionStatus;
buffer[0] = reg_addr;
buffer[1] = data;
__disable_irq();
connectionStatus = HAL_I2C_Master_Transmit(&hi2c2, (uint16_t) 0x60, buffer,
2, 100);
if (connectionStatus == HAL_OK) {
opertionStatus = 1;
} else {
opertionStatus = 0;
}
__enable_irq();
return opertionStatus;
}Main Function:
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_I2C2_Init();
MX_USART2_UART_Init();
/* USER CODE BEGIN 2 */
SCCB_Write(0xff, 0x01);
SCCB_Write(0x12, 0x80);
HAL_Delay(10);
......What could be causing this potentially as I have used another Nucleo board and got the same result?
I've connected the pull-ups to 3.3V and it worked on another nucleo board (L476RG NUCLEO) but on the one my project is based on (F446RE Nucleo) it does not work. I've added 3.3V pullups but same issue. I then changed the pins to function as GPIO and toggle them and I got the same result meaning I2C is not the problem. I debugged line by line and discovered the behaviour happens after the clock configuration:
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_SCALE3);
/** 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_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 16;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
RCC_OscInitStruct.PLL.PLLQ = 2;
RCC_OscInitStruct.PLL.PLLR = 2;
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_2) != HAL_OK)
{
Error_Handler();
}
HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_PLLCLK, RCC_MCODIV_2);
}This is what I'm getting now: (Pins are connected straight to logic analyzer as GPIO without pullups).
