I use PlatformIO insted of the Arduino IDE. At the startup, the Arduino try to detect if there is a DRA818 module plugged. If the connexion failed, it goes to the Baofeng mode. The sound (AFSK) is ...

This is an OpenSource project based on Arduino platform, for building a smart watch with some interesting functions: OLED Display, clock RTC, Satellite pass prediction routine, Moon phase routine, ...