TNC-X for Raspberry Pi

Have Your Pi a la mode!

The Official Raspberry Pi Touch Display has now been released. For information on using it to build your own portable APRS Tracker using Xastir check here!

There is now a new version of the TNC-Pi designed to fit the Raspberry Pi model B+, Pi 2 and Pi 3 perfectly! See below for details!


The original TNC-Pi sits atop Raspberry Pi version B. The 9 pin D-sub connector interfaces to your radio.

TNC-Pi is a special version of TNC-X designed to interface directly with the Raspberry Pi computer. It can connect to the Pi either via the Pi's serial port, or via the I2C protocol. In the latter case, a single Pi can support multiple TNC-Pi's at the same time, since each TNC-Pi can be given a unique I2C address.

The firmware for TNC-Pi was based on the original TNC-X open source code by John Hansen, W2FS as modified by John Wiseman, G8BPQ to support the I2C protocol as well as the original serial port connection.

TNC-Pi 2

Here is the new Pi 2 sitting atop a Raspberry Pi version B+. It also fits the Pi 2 and Pi 3 perfectly.

The TNC-Pi 2 is Now Here!

The TNC-Pi 2 is designed to perfectly match the form factor of the Raspberry Pi B+, Pi2 and Pi 3 models. All 40 header pins are communicated to the top of the TNC-Pi 2 board. The standoff has been repositioned to the bottom left corner to add greater stability. The TNC-Pi 2 no longer needs any jumpers to be configured. Otherwise the TNC-Pi 2 is functionally identical to the original TNC-Pi and there have been no changes in the firmware.

The new TNC-Pi 2 is designed to fit the B+, Pi 2 and Pi 3 boards only. The original TNC-Pi will also fit the B+, Pi 2, and Pi 3 boards, but because it was designed for the original Pi version B, the form factor is not the same and only the first 26 pins are communicated through the TNC-Pi board. The original TNC-Pi will continue to be available indefinitely.

There are lots of potential applications for TNC-Pi. Here you see the APRS program Xastir running on the Pi driving a TNC-Pi via the serial connection. With this setup you've got most of the functionality of a D700/Avmap combination at less than a quarter the cost.

Want to send and receive e-mail on your Raspberry Pi using the Winlink system rather than the Internet? Check out Mark Griffith's PiGate at!

Here's Xastir running on a Raspberry Pi with a TNC-Pi and a 7" Raspberry Pi Touch Display ($60). The Raspberry Pi is mounted on the back of the monitor and the TNC-Pi is mounted on the Pi. This makes a very portable APRS station with the only wire connections being a micro USB power cable and a cable to the radio. For more information check here.
Xastir on TNC-Pi
TNC-Pi with RPi Monitor
Imagine running a pair of TNC-Pi's with a single Raspberry Pi to create a dual frequency digipeater. G8BPQ has created a new version of his venerable BPQ multi-port packet program that will support this.
TNC-Pi Stack


TNC-Pi is a fun, easy to build kit. All parts are through-hole; there's absolutely no surface mount soldering involved. You can view a copy of the manual here. It is shipping now and is $10 cheaper than the original TNC-X!

If you have any questions contact John Hansen W2FS at:

TNC-Pi 2 (TNC-X for Raspberry Pi B+, Pi 2, and Pi3) Kit ($40)

TNC-Pi 2 (TNC-X for Raspberry Pi B+, Pi 2, and Pi3) wired and tested ($65)

Original TNC-Pi (TNC-X for Raspberry Pi) Kit ($40)

Original TNC-Pi (TNC-X for Raspberry Pi) wired and tested($65)

9 Pin DSUB connector (if you plan to build your own radio cable) ($3)

If you want to stack 2 or more TNC's on a single Pi, this Male/Female standoff will help ($0.50)

Do you need a cable to connect your TNC-Pi to a Baofeng HT? We have them here.