[stm32 Hal library] RTC and BKP drives

CubeMX To configure

1. Turn on the external clock
   

2. Activate the clock and calendar
   

3. change RCC The clock is an external low-speed clock
   
   Above in CubeMX The configuration in has been completed , Click generate code .

4. Here I need to use the serial port for debugging , Therefore, the serial port 1 is opened

Engineering modification

After the above configuration ,RCC It can run normally , But when the MCU is reset ,RCC The clock will clear , This is not in line with our purpose .
therefore , stay RCC We add these two lines of code to the initialization function ：
Turn on BKP Standby register clock and cancel its write protection .

Then we add 55 That's ok 56 That's ok 57 Row sum 83 Line code to judge whether the time is set for the first time , If it is the first time to initialize the time , Then change the flag bit , After that, do it anyway , Reset , Turn off the power , This flag bit will not change .

Realize the basic time travel and read

1. Define two structures for saving time and data in the main function , And configure data such as time and date
2. Write time data

HAL_RTC_SetTime(&hrtc, &RtcTime, RTC_FORMAT_BIN)
HAL_RTC_SetDate(&hrtc, &RtcDate, RTC_FORMAT_BIN)

3. Read time data

HAL_RTC_GetTime(&hrtc, &RtcTime,RTC_FORMAT_BIN);
HAL_RTC_GetDate(&hrtc, &RtcDate,RTC_FORMAT_BIN);