Using the realtime clock of the STM32 to display the date and time value and an I²C display.

Notion Project Documentation

• Use the Real-Time-Clock RTC of the STM32
• Display the time every second in the format TT:MM - HH:MM:SS
• Using the UART, the time can be modified

• NUCLEO-F413ZH
• Freenove LCD1602

• sets the RTC with UART
• checks the time input from UART
• checks the date input from UART
• uses interrupts to receive input
• does not require to type the symbols : and -
• considers leap years
• document and beautify RTC code

• uses interrupt to synchronize RTC value to the display
• only synchronize data every second
• use RTC alarm interrupt instead of timer interrupt

• initializes display
• use the I²C-2 and set to 100kHz clock frequency (max rating of display)
• connect PB -> SDA, PB9 -> SCL, GND and a supply voltage of 5V
• I²C communication error lights up the red onboard led
• check and document initialisation and transfer code

HAL_I2C_Transmit is expensive because of decreased I²C speed of the display!

• send all characters to the display in one HAL_I2C_Transmit call
• use asynchronous transmit to transfer the data to the display
• only transfer changed chars