I am trying to use a comparator on my STM32G474RE nucleo board and the external output gives the expected output when measured with an oscilloscope, but using the HAL_COMP_TriggerCallback function is just constantly called for no discernible reason, even if nothing is happening at the external COMP output.
I genuinely have no idea why HAL_COMP_TriggerCallback just gets repeatedly called at about 370kHz for no reason. This happens no matter what is going on at the COMP inputs. If I let the MCU sit and run for about 20 minutes, it stops being called randomly, but still does not get called when it should.
main.c and comp.c shown below:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2024 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 "comp.h"
#include "usart.h"
#include "tim.h"
#include "gpio.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 ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* 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 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
if (GPIO_Pin == B1_Pin) {
//print("Test");
TIM1->ARR = TIM1->ARR - 2;
TIM1->CCR1 = TIM1->CCR1 - 1;
HAL_GPIO_TogglePin(GPIOA, LD2_Pin);
}
}
/* 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_LPUART1_UART_Init();
MX_TIM8_Init();
MX_COMP4_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
HAL_COMP_Start(&hcomp4);
// MIN FREQ: 150 kHz = ARR 1133
// MAX FREQ: 400 kHz = ARR 425
// START FREQ: 200 kHz = ARR 850
TIM8->ARR = 680;
TIM8->CCR1 = 680/2;
HAL_TIM_PWM_Start(&htim8, TIM_CHANNEL_1);
HAL_TIMEx_PWMN_Start(&htim8, TIM_CHANNEL_1);
while (1)
{
/* 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};
/** Configure the main internal regulator output voltage
*/
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1_BOOST);
/** 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 = RCC_PLLM_DIV4;
RCC_OscInitStruct.PLL.PLLN = 85;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
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_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
{
Error_Handler();
}
}
/* 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 comp.c
* @brief This file provides code for the configuration
* of the COMP instances.
******************************************************************************
* @attention
*
* Copyright (c) 2024 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 "comp.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
COMP_HandleTypeDef hcomp4;
/* COMP4 init function */
void MX_COMP4_Init(void)
{
/* USER CODE BEGIN COMP4_Init 0 */
/* USER CODE END COMP4_Init 0 */
/* USER CODE BEGIN COMP4_Init 1 */
/* USER CODE END COMP4_Init 1 */
hcomp4.Instance = COMP4;
hcomp4.Init.InputPlus = COMP_INPUT_PLUS_IO1;
hcomp4.Init.InputMinus = COMP_INPUT_MINUS_IO2;
hcomp4.Init.OutputPol = COMP_OUTPUTPOL_NONINVERTED;
hcomp4.Init.Hysteresis = COMP_HYSTERESIS_NONE;
hcomp4.Init.BlankingSrce = COMP_BLANKINGSRC_NONE;
hcomp4.Init.TriggerMode = COMP_TRIGGERMODE_IT_RISING_FALLING;
if (HAL_COMP_Init(&hcomp4) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN COMP4_Init 2 */
/* USER CODE END COMP4_Init 2 */
}
void HAL_COMP_MspInit(COMP_HandleTypeDef* compHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(compHandle->Instance==COMP4)
{
/* USER CODE BEGIN COMP4_MspInit 0 */
/* USER CODE END COMP4_MspInit 0 */
__HAL_RCC_GPIOB_CLK_ENABLE();
/**COMP4 GPIO Configuration
PB0 ------> COMP4_INP
PB1 ------> COMP4_OUT
PB2 ------> COMP4_INM
*/
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_2;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF8_COMP4;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* COMP4 interrupt Init */
HAL_NVIC_SetPriority(COMP4_5_6_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(COMP4_5_6_IRQn);
/* USER CODE BEGIN COMP4_MspInit 1 */
/* USER CODE END COMP4_MspInit 1 */
}
}
void HAL_COMP_MspDeInit(COMP_HandleTypeDef* compHandle)
{
if(compHandle->Instance==COMP4)
{
/* USER CODE BEGIN COMP4_MspDeInit 0 */
/* USER CODE END COMP4_MspDeInit 0 */
/**COMP4 GPIO Configuration
PB0 ------> COMP4_INP
PB1 ------> COMP4_OUT
PB2 ------> COMP4_INM
*/
HAL_GPIO_DeInit(GPIOB, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2);
/* COMP4 interrupt Deinit */
HAL_NVIC_DisableIRQ(COMP4_5_6_IRQn);
/* USER CODE BEGIN COMP4_MspDeInit 1 */
/* USER CODE END COMP4_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
HAL_COMP_TriggerCallback is in main. I accidentally deleted it from the code block while I was deleting some commented out code.
void HAL_COMP_TriggerCallback(COMP_HandleTypeDef* hcomp) {
if (hcomp->Instance == COMP4) {
HAL_GPIO_TogglePin(COMP1_Callback_GPIO_Port, COMP1_Callback_Pin);
}
}
(Ignore the fact that some variables are named COMP1_xxx.)
I tried placing a pull-down resistor on COMP INP but HAL_COMP_TriggerCallback continues to be triggered.
The flag is reset in the auto generated (By STM32CubeMX) HAL_COMP_IRQHandler function, which then calls HAL_COMP_TriggerCallback.
__HAL_COMP_COMP4_EXTI_CLEAR_FLAG(); is unessecary as LL_EXTI_ClearFlag_0_31(exti_line); is called in HAL_COMP_IRQHandler.
I tried adding it anyway, but it does not solve the issue of HAL_COMP_TriggerCallback being randomly called.