This is a WSPR Beacon made with arduino, gps neo-7-m, lcd and SI5351 adafruit. I use they library: SoftwareSerial, TinyGPS++, etherkit/si5351, and LiquidCrystal_I2C.
More infos on http://www.f4htb.fr/2018/01/02/balise-wspr-multibandes/