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STM32G0B1KBU3N I2C comms, can't see wave form
Hello again :)
I have used all ideas including chat GPT. I can't see any changes in I2C line with oscilloscope. STM32G0B1KBU3N have Pin PB9 as SDA and PA9 as SLC. 3.3Volts pull up via 4.7 kOhm resistor. I am trying negotiate with LM51772 DC-DC buck-boost converter. No external clock crystal. I am sure the issue in the code but because lack op experience cant see where. Please support with the solution. Below is the code and the debug message. I am in desperate. Thank you.
set *(int *)0xE000EDFC=*(int *)0xE000EDFC|0x400 Temporary breakpoint 1, main () at ../Core/Src/main.c:82 82 HAL_Init();
/* 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"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#define LM51772_ADDR (0x6A << 1) // 8-bit I2C address
#define IVP_VOLTAGE_REG 0xDA // Output voltage register
#define CONTROL_REG1 0x01 // Example: control/config register
#define VOLTAGE_20V_VALUE 0x7A // From datasheet table
#define ENABLE_IVP 0x01 // Bit to enable I2C voltage programming
/* USER CODE END Includes */
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;
/* 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_UCPD1_Init(void);
/* USER CODE BEGIN 0 */
void LM51772_SetOutput20V(void)
{
uint8_t buf[2];
// Step 1: Enable I2C programmable voltage (IVP)
buf[0] = CONTROL_REG1; // Control register address
buf[1] = ENABLE_IVP; // Set IVP enable bit
if (HAL_I2C_Master_Transmit(&hi2c1, LM51772_ADDR, buf, 2, HAL_MAX_DELAY) != HAL_OK)
{
Error_Handler();
}
HAL_Delay(1); // small delay to let settings apply
// Step 2: Set target voltage (20V)
buf[0] = IVP_VOLTAGE_REG; // Voltage register
buf[1] = VOLTAGE_20V_VALUE;
if (HAL_I2C_Master_Transmit(&hi2c1, LM51772_ADDR, buf, 2, HAL_MAX_DELAY) != HAL_OK)
{
Error_Handler();
}
HAL_Delay(1); // allow the chip to update output
}
/* 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();
/* Configure the system clock */
SystemClock_Config();
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_I2C1_Init();
MX_UCPD1_Init();
/* USER CODE BEGIN 2 */
// Set initial LED states
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_7, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_0, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_1, GPIO_PIN_SET);
// Configure LM51772 output voltage
LM51772_SetOutput20V();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
// Toggle LEDs
HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_7);
HAL_Delay(500);
HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_0);
HAL_Delay(500);
HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_1);
HAL_Delay(500);
/* 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};
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV1;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
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();
}
}
/**
* @brief I2C1 Initialization Function
* @retval None
*/
static void MX_I2C1_Init(void)
{
hi2c1.Instance = I2C1;
hi2c1.Init.Timing = 0x10301313;
hi2c1.Init.OwnAddress1 = 0;
hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c1.Init.OwnAddress2 = 0;
hi2c1.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c1) != HAL_OK)
{
Error_Handler();
}
if (HAL_I2CEx_ConfigAnalogFilter(&hi2c1, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
{
Error_Handler();
}
if (HAL_I2CEx_ConfigDigitalFilter(&hi2c1, 0) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief UCPD1 Initialization Function
* @retval None
*/
static void MX_UCPD1_Init(void)
{
LL_GPIO_InitTypeDef GPIO_InitStruct = {0};
/* Peripheral clock enable */
LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_UCPD1);
LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOB);
LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA);
/**UCPD1 GPIO Configuration
PB15 ------> UCPD1_CC2
PA8 ------> UCPD1_CC1
*/
GPIO_InitStruct.Pin = LL_GPIO_PIN_15;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
GPIO_InitStruct.Pin = LL_GPIO_PIN_8;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}
/**
* @brief GPIO Initialization Function
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* Enable GPIO clocks */
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/* Configure LEDs */
GPIO_InitStruct.Pin = GPIO_PIN_7;
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);
GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* Configure I2C1 Pins */
// PA9 = SCL
GPIO_InitStruct.Pin = GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF6_I2C1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
// PB9 = SDA
GPIO_InitStruct.Pin = GPIO_PIN_9;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
__disable_irq();
while (1)
{
}
}
#ifdef USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{
// User can add implementation to report file name and line number
}
#endif