real time clock RTC
Introduction to RTC
- An automatic wake-up service can be provided to restore the microcontroller from low-power mode to normal operating mode.
- RTC is an independent BCD code (binary coded decimal number) timer and counter.
- Can provide time, date, year and other information
- As long as the external power supply voltage is still within the power supply range, the RTC will not stop counting.
- Digital calibration with high accuracy
- The clock source of RTC can be selected from LSE or HSI (both are external crystal oscillators)
- RTC can also choose the internal LSI 32-bit slow clock source
programming
- [Template] As a project for STM32CUBEMX generated code;
- Enable the clock and calendar functions of RTC;
- According to the requirements, configure the clock and initialization status of the RTC, and configure the clock input to the RTC module to 1Hz!
- Migrate rtc.c and rtc.h to [Programming Project]
4.1main.c contains #include "rtc.h"
4.2 Start the RTC module in stm32g4xx hal confh
4.3 Clock initialization, be sure to initialize LSI as the clock source of RTC
4.4 Call HAL RTC GetTime and HAL RTC GetDate get time and date!
Find the RTC under timers, and then check the first two options to turn on the clock source and timing function of the RTC:
Then we can see that the clock source in the clock tree has been configured as LSI (32khz internal low-speed clock) by default, so keep the default That’s it.
The next step is to configure the frequency division value and prescaler value so that the RTC frequency is 1HZ.
The default frequency division value and prescaler value given here are:
128*256=32768 (the frequency division starts from 0, so 127 is actually 128), that is, if the RTC is connected to a crystal oscillator The frequency is 32768HZ, then after prescaling by 127 and dividing by 255, the frequency of RTC is 1HZ.
But the clock source we are connecting now is 32KHZ, so this value is problematic. So we should change these two values.
For example, just change it to 31 and 999.
Then some of the following parameters can be set as follows, so that we can observe the phenomenon:
the code can then be generated and transplanted.
The most important thing to remember is that the transplantation of RTC requires a step to initialize the LSI as the clock source of RTC:
use the following program in main.c in the template:
/** Initializes the peripherals clocks
*/
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_ADC12;
PeriphClkInit.Adc12ClockSelection = RCC_ADC12CLKSOURCE_SYSCLK;
PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
Replace the following paragraph in the programming file main.c:
/** Initializes the peripherals clocks
*/
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC12;
PeriphClkInit.Adc12ClockSelection = RCC_ADC12CLKSOURCE_SYSCLK;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
}
Then write the startup program of RTC:
RTC_TimeTypeDef rtc_time;
RTC_DateTypeDef rtc_date;
void RTC_Process(void)
{
HAL_RTC_GetTime(&hrtc,&rtc_time,RTC_FORMAT_BIN);
HAL_RTC_GetDate(&hrtc,&rtc_date,RTC_FORMAT_BIN);
}
The complete main.c is as follows:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* <h2><center>© Copyright (c) 2021 STMicroelectronics.
* All rights reserved.</center></h2>
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "gpio.h"
#include "led.h"
#include "key.h"
#include "i2c.h"
#include "dac.h"
#include "rtc.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 */
//Led执行程序
__IO uint32_t ledTick =0,keyTick=0;
u8 led_ctrl=0xff;
void LED_Process(void)
{
if(uwTick-ledTick<500)return;
ledTick=uwTick;
LED_Control(led_ctrl);
led_ctrl=~led_ctrl;
}
//KEY
void KEY_Process(void)
{
if(uwTick-keyTick<10)return;
keyTick=uwTick;
Key_Read();
// if(Trg&0x01)
// {
// LED_Control(0x01);
// }
if(Trg)
{
LED_Control(Trg);
}
}
//EEPROM
u8 val_24c02=0;
//DAC
u16 dac_ch1_val,dac_ch2_val;
void DAC_Process(void)
{
dac_ch1_val=(1.1f/3.3f*4095);//输出1.1V
dac_ch2_val=(2.1f/3.3f*4095);//输出2.2V
HAL_DAC_SetValue(&hdac1,DAC_CHANNEL_1,DAC_ALIGN_12B_R,dac_ch1_val);//0->0V;4095->3.3V
HAL_DAC_Start(&hdac1,DAC_CHANNEL_1);
HAL_DAC_SetValue(&hdac1,DAC_CHANNEL_2,DAC_ALIGN_12B_R,dac_ch2_val);//0->0V;4095->3.3V
HAL_DAC_Start(&hdac1,DAC_CHANNEL_2);
}
//RTC
RTC_TimeTypeDef rtc_time;
RTC_DateTypeDef rtc_date;
void RTC_Process(void)
{
HAL_RTC_GetTime(&hrtc,&rtc_time,RTC_FORMAT_BIN);
HAL_RTC_GetDate(&hrtc,&rtc_date,RTC_FORMAT_BIN);
}
//LCD
void LCD_Process(void)
{
u8 display_buf[20];
sprintf((char*)display_buf,"%02d-%02d-%02d",rtc_time.Hours,rtc_time.Minutes,rtc_time.Seconds);
LCD_DisplayStringLine(Line0,display_buf);
sprintf((char*)display_buf,"%04d-%02d-%02d",rtc_date.Year,rtc_date.Month,rtc_date.Date);
LCD_DisplayStringLine(Line1,display_buf);
sprintf((char*)display_buf,"EEPROM:%d",val_24c02);
LCD_DisplayStringLine(Line2,display_buf);//输出百分号：%
}
/* 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();
/* USER CODE BEGIN 2 */
LCD_Init();
LED_Control(0x00);
MX_DAC1_Init();
MX_RTC_Init();
I2CInit();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
LCD_Clear(Blue);
LCD_SetBackColor(Blue);
LCD_SetTextColor(White);
EEPROM_Write(0x10,0x55);
val_24c02=EEPROM_Read(0x10);
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
LED_Process();
KEY_Process();
DAC_Process();
RTC_Process();
LCD_Process();
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {
0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {
0};
RCC_PeriphCLKInitTypeDef PeriphClkInit = {
0};
/** Configure the main internal regulator output voltage
*/
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the CPU, AHB and APB busses clocks
*/
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_DIV2;
RCC_OscInitStruct.PLL.PLLN = 20;
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 busses 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_3) != HAL_OK)
{
Error_Handler();
}
/** Initializes the peripherals clocks
*/
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_ADC12;
PeriphClkInit.Adc12ClockSelection = RCC_ADC12CLKSOURCE_SYSCLK;
PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != 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 */
/* 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,
tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/