The First TNC to Offer Both USB and Bluetooth

Just $50!


TNC-Pi and TNC-Pi9K6 are versions of TNC-X that have been adapted specifically for the Raspberry Pi!. See below.


BlueTooth is Now Available for TNC-X! --So you can now use APRS from your Android SmartPhone (details here)!



goto ordering information

goto USB driver installation information

TNC-X Documentation Page (manual, schematic, source code, etc.)

What is a "KISS Mode" TNC and why would I want one?

How to use TNC-X with the AGW Packet Engine.

TNC-X with USB option installed

Daughter Boards for TNC-X:

X-BT2: Bluetooth for the TNC-X.

APRS on Your Android Smart Phone!

X-Digi: Add A Digipeater to TNC-X!

X-Track: Make your TNC-X a Tracker!


Connectors (Left to Right): Auxilliary Serial port, Serial Port, USB Port, External Power, Radio Connector

TNC-X is a Terminal Node Controller (kit) design based on the Chepponis/Karn KISS protocol. It is implemented using a Microchip PIC 16F628A microcontroller, a CML MX614 Bell 202 (1200 baud AX.25) modem chip, an 8K Ramtron FRAM, a MAX232A level converter chip, and an op-amp which provides active audio filtering for the modem. From the beginning, this TNC was designed to be small, inexpensive, have low power consumption, and expandable.

TNC-X features an 8 pin expansion header that allows the addition of "daughter boards". Power is provided to the daughter board through the expansion header. In addition, signals that would otherwise go to or from a host PC can be intercepted by the daughter board at the TTL level and processed. The I/O on the expansion header speaks "KISS" so that any daughter board only has to send and receive data packaged in KISS format to access the core module. This makes the development of daughter boards fairly simple and inexpensive. For example, daughterboards are now available that can turn TNC-X into a digitpeters (see a X-Digi) or into a stand alone Tracker (see X-Track). In addition, the expansion header provides access to a second on-board serial port. The X-Track daughterboard, for example, uses this port to receive data from a GPS receiver. The data is then processed and formed into packets and an APRS beacon is sent.

TNC-X is available in two versions: with and without a USB port. Both versions contain a standard serial port, but the USB version also allows the TNC to be connected to a computer via it's USB port as well. Drivers that are shipped with the module make it appear to the host PC as a standard serial port. Thus PC software that expects to see a serial port on the computer will interpret the TNC-X as being connected to such a port, even when the PC has no serial ports, or they are all used by other applications. In addition, when the USB option is used, the TNC can be powered from the USB port of the computer; no other power supply is needed.

Even without daughter boards (or the USB option) the device works as a fully functional stand alone KISS mode TNC. The idea behind the expansion options was to provide a platform that would allow additional functionality to be added to the unit with the investment of very little design time and very few parts.

Any questions concerning TNC-X can be directed to the developer, John Hansen, W2FS.

Are you planning to use TNC-X with a Baofeng HT (UV-5R or similar)? Read this for a discussion on connecting the Baofeng to the TNC-X.

Here are some common configurations you can order with one button press:

Complete TNC-X kit with USB and Enclosure ($88)

Complete Wired and Tested TNC-X including USB and Enclosure ($123)

Or customize your own TNC-X by ordering just the features you need:

TNC-X rev 2.6 Kit without enclosure or USB($50 plus shipping)

TNC-X Wiring and Testing Service - Complete Unit ($35)

USB option for TNC-X ($20)

Note: This option works only with rev 2.6 boards and must be ordered at the same time as TNC-X.

X-BT2 BlueTooth Daughter Board Option for TNC-X ($25)

TNC-X Custom Drilled Enclosure for TNC-X ($18)

Note: This enclosure will only work with revision 2.2 thru 2.6 boards.

5 Pin DIN Plug ($2)

Note: The radio connector on the back of TNC-X is designed to work with pre-wired MFJ and BuxComm TNC to Radio cables. Or you can build one of your own. This plug, which used to be available at every Radio Shack store, is no longer carried there. For your convenience, you can order one here if you need it.


TNC to Radio Cables

We generally do not sell TNC to Radio cables because there are so many different radios available. There are, however, other companies that sell these cables including BuxComm and MFJ. In addition , there is one packet connector that is used on a lot of radios (for example: ICOM IC-207, IC-208, IC-2720, IC-2800, IC-9100, IC-880H, Kenwood D-710, TM-255, TM-455, TM-733, TM-833, TM-G707, TM-V7A, TX-480, TM-V71, Yaesu FT-100, FT-1500, FT-300, FT-450, FT-7100, FT-7800, FT-7900, FT-8000, FT-8100, FT-817, FT-8500, FT-857, FT-8800, FT-8900, FT-897, FT-90, FT-950. The radio jack for this connection is a 6 pin mini-DIN jack (like you used to see on PS/2 keyboards and mice.). For these radios only, we do sell the following pre-wired cable: 5 Pin DIN to 6 Pin mini-DIN pre-wired cable. ($20).

5 Pin DIN to 6 Pin Mini-DIN TNC/Radio Cable ($20).

In addition, we now offer a cable for the Baofeng UV-5R or similar:

TNC-X Cable for Baofeng UV-5R or Similar ($20).


Do You Have a Raspberry Pi? Here are TNC Options Available Just for You!



NEW!! TNC-Pi9K6: Finally a Low Cost 9600 Baud TNC!

TNC-Pi9K6 is a special version of TNC-X designed to interface directly with the Raspberry Pi computer. It supports 1200 baud, 2400 baud and 9600 baud packet. In addition to standard packet, this board will also support the ARDOP protocol for HF operation.

For More Infomation click here.


TNC-Pi    A Specialized Version of TNC-X For the Raspberry Pi

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.

For More Information click here.