Configuration of the Timestamp using the RTC LL API. The peripheral initialization uses LL unitary service functions for optimization purposes (performance and size).
In this example, after start-up, SYSCLK is configured to the max frequency using HSI as clock source.
The RTC peripheral configuration is ensured by the Configure_RTC() function (configure of the needed RTC resources according to the used hardware CLOCK, PWR, RTC clock source and BackUp). You may update this function to change RTC configuration.
LSI oscillator clock is used as RTC clock source by default.
The user can use also LSE as RTC clock source.
The user uncomment the adequate line on the main.c file.
@code
#define RTC_CLOCK_SOURCE_LSI
/* #define RTC_CLOCK_SOURCE_LSE */
@endcode
Open the ioc file with STM32CubeMX and select :
LSE as “Crystal/Ceramic Resonator” in RCC configuration.
LSE as RTC clock source in Clock configuration.
Generate code
LSI oscillator clock is delivered by a 32 kHz RC.
LSE (when available on board) is delivered by a 32.768 kHz crystal.
Configure_RTC_TimeStamp() function is then called to initialize the time stamp feature with interrupt mode. It configures the time stamp pin to be rising edge and enables the time stamp detection on time stamp pin. LL_RTC_DATE_Config()and LL_RTC_TIME_Config() functions are then called to initialize the time and the date.
The associated firmware performs the following:
After start-up the program configure the RTC (Time date) and enable the feature timeStamp.
When applying a rising edge on the time stamp pin (PC.13), a time stamp event is detected and the calendar is saved in the time stamp structures. The current date and time stamp are updated and displayed.
Note: On this board, time stamp pin is connected to User push-button (connection to pin PC.13). Therefore, no external connection is needed: each action on User push-button will trig a time stamp event.
On the debugger (live watch) in aShowTimeStamp and aShowDateStamp variables . The current time and date are updated and displayed on the debugger (live watch) in aShowTime, aShowDate variables .
RTC, Timer, Timestamp, Counter, LSE, LSI, Current time, Real Time Clock
This example runs on STM32C031C6Tx devices.
This example has been tested with NUCLEO-C031C6 board and can be easily tailored to any other supported device and development board.
In order to make the program work, you must do the following :