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-Digi: Add A Digipeater to TNC-X!


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).

TNC-X also contains a serial port. 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.