Experimental Amateur Radio single sketch Arduino NRF24L01 2.4 GHz (13cm band) USB serial KISS TNC/modem.
Could be used with Linux AX25 tools to setup point to point packet network, for example broadband hamnet node or use it with other tools such as APRSDroid or Codec2 Walkie-Talkie.
Operates via PC USB interface or USB OTG on Android.
Similar modem, but based on LoRa: https://github.com/sh123/lora_arduino_kiss_modem
- NRF24 library (just install via libraries): https://github.com/nRF24/RF24