FaBoRTC-PCF2129-Library This is a library for FaBo #215 RTC I2C Brick. FaBo RTC I2C Brick #215 RTC I2C Brick PCF2129 PCF2129 is RTC with integrated quartz crystal PCF2129 Datasheet PCF2129 Datasheet Releases 1.0.0 Initial release. How to install Installing Additional Arduino Libraries