HAL_COMP_TriggerCallback called at 370 kHz no matter what.

Haeden · ‎2024-04-06

I am trying to use a comparator on my NUCLEO-STM32G474RE dev board.

The issue I am encountering is that while the external COMP1 output is correct when measured with an oscilloscope, the output due to HAL_COMP_TriggerCallback is simply a 370 kHz signal, no matter what inputs the comparator has, or what is measured on the external comp output.

/* 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_COMP_TriggerCallback(COMP_HandleTypeDef* hcomp) {
  if (hcomp->Instance == COMP1) {
    HAL_GPIO_TogglePin(COMP1_Callback_GPIO_Port, COMP1_Callback_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_COMP1_Init();
  MX_TIM8_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */

  HAL_COMP_Start(&hcomp1);



  // 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 hcomp1;

/* COMP1 init function */
void MX_COMP1_Init(void)
{

  /* USER CODE BEGIN COMP1_Init 0 */

  /* USER CODE END COMP1_Init 0 */

  /* USER CODE BEGIN COMP1_Init 1 */

  /* USER CODE END COMP1_Init 1 */
  hcomp1.Instance = COMP1;
  hcomp1.Init.InputPlus = COMP_INPUT_PLUS_IO1;
  hcomp1.Init.InputMinus = COMP_INPUT_MINUS_IO2;
  hcomp1.Init.OutputPol = COMP_OUTPUTPOL_NONINVERTED;
  hcomp1.Init.Hysteresis = COMP_HYSTERESIS_NONE;
  hcomp1.Init.BlankingSrce = COMP_BLANKINGSRC_NONE;
  hcomp1.Init.TriggerMode = COMP_TRIGGERMODE_IT_RISING_FALLING;
  if (HAL_COMP_Init(&hcomp1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN COMP1_Init 2 */

  /* USER CODE END COMP1_Init 2 */

}

void HAL_COMP_MspInit(COMP_HandleTypeDef* compHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(compHandle->Instance==COMP1)
  {
  /* USER CODE BEGIN COMP1_MspInit 0 */

  /* USER CODE END COMP1_MspInit 0 */

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**COMP1 GPIO Configuration
    PA0     ------> COMP1_INM
    PA1     ------> COMP1_INP
    PA6     ------> COMP1_OUT
    */
    GPIO_InitStruct.Pin = GPIO_PIN_0|Current_OUT_Pin;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF8_COMP1;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* COMP1 interrupt Init */
    HAL_NVIC_SetPriority(COMP1_2_3_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(COMP1_2_3_IRQn);
  /* USER CODE BEGIN COMP1_MspInit 1 */

  /* USER CODE END COMP1_MspInit 1 */
  }
}

void HAL_COMP_MspDeInit(COMP_HandleTypeDef* compHandle)
{

  if(compHandle->Instance==COMP1)
  {
  /* USER CODE BEGIN COMP1_MspDeInit 0 */

  /* USER CODE END COMP1_MspDeInit 0 */

    /**COMP1 GPIO Configuration
    PA0     ------> COMP1_INM
    PA1     ------> COMP1_INP
    PA6     ------> COMP1_OUT
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_0|Current_OUT_Pin|GPIO_PIN_6);

    /* COMP1 interrupt Deinit */
    HAL_NVIC_DisableIRQ(COMP1_2_3_IRQn);
  /* USER CODE BEGIN COMP1_MspDeInit 1 */

  /* USER CODE END COMP1_MspDeInit 1 */
  }
}

/* USER CODE BEGIN 1 */

/* USER CODE END 1 */

Haeden · ‎2024-04-06

Further Info: If the program is left to sit and run for about 10-20 minutes, this random calling of HAL_COMP_TriggerCallback stops. However, after that it is not called at all, no matter what happens with the comparator, while its external input continues to function as normal.