Wake up Nucleo L432KC from Standby mode with external RTC

[hysha2000]

Hey guys,

i am a new member. I am using the Nucleo L432kc board for my masters thesis. I want it to work with the lowest power consumption can me. I am using an external very low power RTC, and i am trying to programm it to wake the board up every 30 seconds. Unfortunately it doesnt work. The RTC is connected with i2c with the board and the nINT Pin of the RTC is connected to PA0 Pin of the board for the interrupt. i dont know what i am doing wrong. So i checked the connections and the i2c is fine. but it doesnt work that it counts to 30 then wakes the board up to say "Ich bin wach!" (im awake). I am a new programmer. I first tried with stop mode and configured the PA0 Pin as a GPIO_EXTI.  Can someone maybe help me? this is my code for now:

/* 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"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define RTC_I2C_ADDRESS 0x52
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;

UART_HandleTypeDef huart2;

/* USER CODE BEGIN PV */
uint8_t timer_value[2] = {0x1E, 0x00}; // 30 Sekunden in Hexa links ist das Least significant byte also 1E und rechts ist das MSB also 00: insgesamt 0x001E
volatile uint8_t count = 0;
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_I2C1_Init(void);
/* USER CODE BEGIN PFP */
int __io_putchar(int ch)
{
  HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, HAL_MAX_DELAY);
  return ch;
}

void RTC_SetCountdownTimer(void)
{
  HAL_I2C_Mem_Write(&hi2c1, RTC_I2C_ADDRESS, 0x0A, I2C_MEMADD_SIZE_8BIT, &timer_value[0], 1, HAL_MAX_DELAY);  // Write lower byte
  HAL_I2C_Mem_Write(&hi2c1, RTC_I2C_ADDRESS, 0x0B, I2C_MEMADD_SIZE_8BIT, &timer_value[1], 1, HAL_MAX_DELAY);  // Write upper byte

  uint8_t control1 = 0x80;  // Enable repeat mode
  HAL_I2C_Mem_Write(&hi2c1, RTC_I2C_ADDRESS, 0x0F, I2C_MEMADD_SIZE_8BIT, &control1, 1, HAL_MAX_DELAY);  // Set control register

  uint8_t control2 = 0x10;  // Enable Timer Interrupt
  HAL_I2C_Mem_Write(&hi2c1, RTC_I2C_ADDRESS, 0x10, I2C_MEMADD_SIZE_8BIT, &control2, 1, HAL_MAX_DELAY);  // Set control register
}

void CheckRTCFlag(void)
{
    uint8_t status;
    // Read Status register (0Eh)
    HAL_I2C_Mem_Read(&hi2c1, RTC_I2C_ADDRESS, 0x0E, I2C_MEMADD_SIZE_8BIT, &status, 1, HAL_MAX_DELAY);
    printf("RTC Status: 0x%02X\n",status);

    if (status & 0x08)  // Check if Timer Flag (TF) is set (bit 3 of status)
    {
    	count++;  // Zähler erhöhen
    	printf("Zähler: %d\n", count);  // Aktuellen Zähler ausgeben

    	// Wenn Zähler 20 erreicht, Timer deaktivieren
    	        if (count >= 20)
    	        {
    	            printf("Timer Test abgeschlossen!\n");
    	            // Hier kannst du den Timer deaktivieren, falls nötig
    	            // z.B. HAL_I2C_Mem_Write(...); um den Interrupt zu deaktivieren
    	        }

    	        // Clear the Timer Flag by writing 0 to bit 3
    	status &= ~(0x08);
    	HAL_I2C_Mem_Write(&hi2c1, RTC_I2C_ADDRESS, 0x0E, I2C_MEMADD_SIZE_8BIT, &status, 1, HAL_MAX_DELAY);
     }
}
/* Funktion für I2C-Scan */
void I2C_Scan(void)
{
  for (uint8_t i = 1; i < 128; i++)
  {
    if (HAL_I2C_IsDeviceReady(&hi2c1, (i << 1), 1, 10) == HAL_OK)
    {
      printf("I2C device found at address 0x%X\n", i);
    }
  }
}
/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{

  /* USER CODE BEGIN 1 */
  printf("Test um zu schauen ob die RTC funktioniert!");
  /* 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_USART2_UART_Init();
  MX_I2C1_Init();
  /* USER CODE BEGIN 2 */
  I2C_Scan();
  RTC_SetCountdownTimer();
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	 HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_SLEEPENTRY_WFI);
	 CheckRTCFlag();
	 //HAL_Delay(2000);
	 //SystemClock_Config();
	 printf("Ich bin wach!hi\n");
    /* 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
  */
  if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure LSE Drive Capability
  */
  HAL_PWR_EnableBkUpAccess();
  __HAL_RCC_LSEDRIVE_CONFIG(RCC_LSEDRIVE_LOW);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE|RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.LSEState = RCC_LSE_ON;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = 0;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
  RCC_OscInitStruct.PLL.PLLM = 1;
  RCC_OscInitStruct.PLL.PLLN = 16;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
  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_1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Enable MSI Auto calibration
  */
  HAL_RCCEx_EnableMSIPLLMode();
}

/**
  * @brief I2C1 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_I2C1_Init(void)
{

  /* USER CODE BEGIN I2C1_Init 0 */

  /* USER CODE END I2C1_Init 0 */

  /* USER CODE BEGIN I2C1_Init 1 */

  /* USER CODE END I2C1_Init 1 */
  hi2c1.Instance = I2C1;
  hi2c1.Init.Timing = 0x00B07CB4;
  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();
  }

  /** Configure Analogue filter
  */
  if (HAL_I2CEx_ConfigAnalogFilter(&hi2c1, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Digital filter
  */
  if (HAL_I2CEx_ConfigDigitalFilter(&hi2c1, 0) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C1_Init 2 */

  /* USER CODE END I2C1_Init 2 */

}

/**
  * @brief USART2 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_USART2_UART_Init(void)
{

  /* USER CODE BEGIN USART2_Init 0 */

  /* USER CODE END USART2_Init 0 */

  /* USER CODE BEGIN USART2_Init 1 */

  /* USER CODE END USART2_Init 1 */
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART2_Init 2 */

  /* USER CODE END USART2_Init 2 */

}

/**
  * @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_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD3_GPIO_Port, LD3_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : PA0 */
  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : LD3_Pin */
  GPIO_InitStruct.Pin = LD3_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(LD3_GPIO_Port, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
  HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
  if (GPIO_Pin == GPIO_PIN_0)
  {
	printf("Ich bin wach lol!\n");
    // Handle the interrupt (RTC wake-up event)
    //HAL_GPIO_TogglePin(GPIOA, LD3_Pin);  // Toggle an LED to indicate wake-up
    //__HAL_GPIO_EXTI_CLEAR_IT(GPIO_PIN_0);
	RTC_SetCountdownTimer();
  }
}

/* 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 */

[Andrew Neil]

Welcome to the forum.

You need to learn to analyse problems beyond "it doesn't work".

What, exactly, is not working?

Think about all the steps that are required to make it work - verify that each one is happening correctly:

• Is your code correctly configuring your external RTC?
• Is your external RTC running?
• Does your RTC generate the required wakeup signal?
• Is that wakeup signal actually reaching the STM32?
• etc, etc, ...

There's more debugging tips here:

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228

[QSHAO.1]

You may need to check firstly if a rising edge was here on nINT pin of RTC. if not, a pull-up may be needed on this pin if it's drive mode is Open Drain.