AVR Real Time Clock
This is a realization of Real Time Clock with battery back-up on the AVR family ATmega328-P MCU.
This is how it works: https://www.youtube.com/watch?v=TeBulb6ntlE
The project uses 128x32 monochrome OLED display based on SSD1306 controller, connected by I2C bus.
Low: 0x62; High: 0xDE; Extended: 0xFE
https://raw.githubusercontent.com/AterLux/RTC/master/RTCBootloader/Debug/RTCBootloader.hex
This tool (for Windows only) can be used to upload main firmware and sych time: https://aterlux.ru/files/RTCsetup.zip
https://raw.githubusercontent.com/AterLux/RTC/master/RTC/Debug/RTC.hex