Arduino UART KISS AFSK1200 TNC Modem

Arduino Nano/Uno TTL UART KISS AFSK1200 TNC based on customized version of LibAPRS.

Introduction

Arduino UART TNC modem is based on customized version of LibAPRS, allows simultaneously work using both UART and USB-serial port. Use this hardware:

• Micromodem shield for Arduino Nano - https://oshpark.com/shared_projects/NjA5xkC7
  • use this schematic: https://github.com/markqvist/MicroModem/blob/master/Design/Schematic.pdf
  • or this schematic: https://unsigned.io/shop/wp-content/uploads/2014/12/Schematic-1.pdf
• or Micromodem from marqvist: http://unsigned.io/micromodem/

Build

• Download and configure platformio for VScode
• Build and upload

Interfacing

• TNC TX pin (5V TTL) - D12 - connect to UART RX
• TNC RX pin (5V TTL) - D11 - connect to UART TX
• GND

use level converter if you plan to connect this TNC to 5V non-tolerant platforms use software compatible with KISS over serial/UART use Arduino USB->serial for basic debug

Radio

• use Line, Mic, PTT pin header to interface your radio via appropriate interface

PC

• use PC, raspberry pi, or any platform with KISS via serial/UART - keep in mind UART TTL levels
• don't use RS232 D9 pins without level conversion, use appropriate UART level converters

Android (not tested)

• use Bluetooth serial adapter HC-05/HC-06 or similar
• connect
  • Bluetooth TX -> TNC RX
  • Bluetooth RX -> TNC TX
  • GND
  • VCC for Bluetooth module - check if you have 5V or 3.3V module
• pair Bluetooth module with Android phone

not each module will work out-of-the-box

iOS or iPadOS with Aprs.fi application

• use https://github.com/tomasgeci/kiss-ble-uart-tnc kiss BLE UART adapter
• use instructions for BLE connection aprs.fi app with the adapter
• connect
  • adapter TX -> TNC RX
  • adapter RX -> TNC TX (with level converter or resistor)
  • GND
  • VCC for BLE UART adapter (use arduino 5V and GND pins)

Credits

• https://oshpark.com/shared_projects/NjA5xkC7 for perfect shield
• http://unsigned.io/micromodem/ for Micromodem and libraries
• https://github.com/sh123/libaprs_bluetooth_tnc for perfect idea and LibAPRS modifications

Suport

License

• GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007