Question
STM32L4 Hard fault exiting from stop mode using comp2
Dear forum,
I have a simple application using an STM32L4 and the analog COMP2 interrupt to blink a PWM LED. The device also uses USB virtual COM port capabilities for a simple terminal with a few commands. Everything works as expected.
Now, I want the device to enter a low power consumption state after some idle time. The device must wake up through the same COMP2 interrupt I'm using to blink the LED. A full system reset is acceptable too.
I'm successfully putting the device into stop mode, and it seems the wake-up interrupt is working as well. However, the problem is that after waking up, the device encounters a hard fault. I've tried everything, but the stack appears to be corrupted. Even NVIC_SystemReset() is not working.
I'm pasting the important parts of my code here. Any help or ideas would be welcome.
/* 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 "usb_device.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdbool.h>
#include <stdint.h>
#include "console.h"
#include "stm32l4xx_hal_gpio.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
#define BASIC 110 //ms
#define PWM_MIN_VAL 30
#define PWM_MAX_VAL 300
#define SHOOT_TIME 50 //ms
#define AWAKE_TIME 10 //seconds
#define ADC_DMA_BUFFER_SIZE ((uint32_t) 32) /* Size of array aADCxConvertedData[] *
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
volatile bool shoot;
uint32_t base_time = 0;
uint8_t sleep_timer = AWAKE_TIME;
volatile uint16_t pwm_value;
volatile uint16_t shoot_time = SHOOT_TIME;
volatile bool in_stop_mode = false;
static uint32_t sleep_counter = 0;
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
COMP_HandleTypeDef hcomp2;
DAC_HandleTypeDef hdac1;
TIM_HandleTypeDef htim1;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_COMP2_Init(void);
static void MX_TIM1_Init(void);
static void MX_DAC1_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
void HAL_COMP_TriggerCallback(COMP_HandleTypeDef *hcomp)
{
if (!shoot)
shoot = true;
}
void Enter_Stop_Mode(void)
{
// __HAL_PWR_CLEAR_FLAG(PWR_FLAG_WUF2);
// __HAL_COMP_COMP2_EXTI_CLEAR_FLAG();
HAL_SuspendTick();
HAL_PWREx_EnterSTOP2Mode(PWR_SLEEPENTRY_WFI);
//SystemClock_Config();
HAL_ResumeTick();
HAL_Delay(1000); // Permitir que el sistema se estabilice
NVIC_SystemReset();
}
/* 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_COMP2_Init();
MX_TIM1_Init();
MX_DAC1_Init();
MX_USB_DEVICE_Init();
/* USER CODE BEGIN 2 */
HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_2, DAC_ALIGN_12B_R, 1500);
HAL_DAC_Start(&hdac1, DAC_CHANNEL_2);
HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_1, DAC_ALIGN_12B_R, 100);
HAL_DAC_Start(&hdac1, DAC_CHANNEL_1);
//HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN2);
__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);
HAL_COMP_Start_IT(&hcomp2);
HAL_TIM_PWM_Start(&htim1, TIM_CHANNEL_1);
__HAL_TIM_SET_COMPARE(&htim1,TIM_CHANNEL_1, PWM_MIN_VAL); //power off laser
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
if (USB_ShouldInitConsole())
{
HAL_Delay(100);
Console_Init();
}
Console_ProcessCommand();
#ifdef BASIC
if (shoot)
{
__HAL_TIM_SET_COMPARE(&htim1,TIM_CHANNEL_1, PWM_MAX_VAL); //power off laser
HAL_Delay(BASIC);
__HAL_TIM_SET_COMPARE(&htim1,TIM_CHANNEL_1, PWM_MIN_VAL); //power off laser
sleep_timer = AWAKE_TIME;
shoot=false;
HAL_Delay(BASIC/2);
HAL_COMP_Start_IT(&hcomp2);
}
#endif
sleep_counter++;
if (sleep_counter >= 200000)
{
sleep_counter = 0; // Reset contador
if (sleep_timer > 0)
{
sleep_timer--;
}
}
if (sleep_timer == 0)
{
__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, 0); // Apagar laser
// Entrar en STOP Mode - al despertar se reiniciará automáticamente
Enter_Stop_Mode();
// Esta línea nunca se ejecutará debido al reset
sleep_timer = AWAKE_TIME;
}
base_time++;
}
/* 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
*/
if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
{
Error_Handler();
}
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_MSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.MSIState = RCC_MSI_ON;
RCC_OscInitStruct.MSICalibrationValue = 0;
RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_11;
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_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
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_0) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief COMP2 Initialization Function
* @PAram None
* @retval None
*/
static void MX_COMP2_Init(void)
{
/* USER CODE BEGIN COMP2_Init 0 */
/* USER CODE END COMP2_Init 0 */
/* USER CODE BEGIN COMP2_Init 1 */
/* USER CODE END COMP2_Init 1 */
hcomp2.Instance = COMP2;
hcomp2.Init.InvertingInput = COMP_INPUT_MINUS_DAC1_CH2;
hcomp2.Init.NonInvertingInput = COMP_INPUT_PLUS_IO1;
hcomp2.Init.OutputPol = COMP_OUTPUTPOL_NONINVERTED;
hcomp2.Init.Hysteresis = COMP_HYSTERESIS_HIGH;
hcomp2.Init.BlankingSrce = COMP_BLANKINGSRC_NONE;
hcomp2.Init.Mode = COMP_POWERMODE_HIGHSPEED;
hcomp2.Init.WindowMode = COMP_WINDOWMODE_DISABLE;
hcomp2.Init.TriggerMode = COMP_TRIGGERMODE_IT_RISING;
if (HAL_COMP_Init(&hcomp2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN COMP2_Init 2 */
__HAL_RCC_SYSCFG_CLK_ENABLE();
/* USER CODE END COMP2_Init 2 */
}
/**
* @brief DAC1 Initialization Function
* @PAram None
* @retval None
*/
static void MX_DAC1_Init(void)
{
/* USER CODE BEGIN DAC1_Init 0 */
/* USER CODE END DAC1_Init 0 */
DAC_ChannelConfTypeDef sConfig = {0};
/* USER CODE BEGIN DAC1_Init 1 */
/* USER CODE END DAC1_Init 1 */
/** DAC Initialization
*/
hdac1.Instance = DAC1;
if (HAL_DAC_Init(&hdac1) != HAL_OK)
{
Error_Handler();
}
/** DAC channel OUT1 config
*/
sConfig.DAC_SampleAndHold = DAC_SAMPLEANDHOLD_DISABLE;
sConfig.DAC_Trigger = DAC_TRIGGER_NONE;
sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
sConfig.DAC_ConnectOnChipPeripheral = DAC_CHIPCONNECT_DISABLE;
sConfig.DAC_UserTrimming = DAC_TRIMMING_FACTORY;
if (HAL_DAC_ConfigChannel(&hdac1, &sConfig, DAC_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
/** DAC channel OUT2 config
*/
sConfig.DAC_ConnectOnChipPeripheral = DAC_CHIPCONNECT_ENABLE;
if (HAL_DAC_ConfigChannel(&hdac1, &sConfig, DAC_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN DAC1_Init 2 */
/* USER CODE END DAC1_Init 2 */
}
/**
* @brief TIM1 Initialization Function
* @PAram None
* @retval None
*/
static void MX_TIM1_Init(void)
{
/* USER CODE BEGIN TIM1_Init 0 */
/* USER CODE END TIM1_Init 0 */
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_OC_InitTypeDef sConfigOC = {0};
TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};
/* USER CODE BEGIN TIM1_Init 1 */
/* USER CODE END TIM1_Init 1 */
htim1.Instance = TIM1;
htim1.Init.Prescaler = 2;
htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
htim1.Init.Period = 256;
htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim1.Init.RepetitionCounter = 0;
htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigOC.OCMode = TIM_OCMODE_PWM1;
sConfigOC.Pulse = 0;
sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
sBreakDeadTimeConfig.DeadTime = 0;
sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
sBreakDeadTimeConfig.BreakFilter = 0;
sBreakDeadTimeConfig.Break2State = TIM_BREAK2_DISABLE;
sBreakDeadTimeConfig.Break2Polarity = TIM_BREAK2POLARITY_HIGH;
sBreakDeadTimeConfig.Break2Filter = 0;
sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM1_Init 2 */
/* USER CODE END TIM1_Init 2 */
HAL_TIM_MspPostInit(&htim1);
}
/**
* @brief GPIO Initialization Function
* @PAram None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/*Configure GPIO pins : PA1 PA3 */
GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_3;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pins : PA6 PA7 */
GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG_ADC_CONTROL;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pins : PA9 PA10 */
GPIO_InitStruct.Pin = GPIO_PIN_9|GPIO_PIN_10;
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(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pin : PB7 */
GPIO_InitStruct.Pin = GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* 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 */