is a firmware replacement for the popular TinyTrak3 line of APRS transmitters.
It creates an easy way to send any simple text message as an AX.25 packet transmission.
ASCII text is sent to the TinyPack via the serial port J2 in one of several baud rates.
Once a complete message is received, TinyPack will key a radio connected to the radio port
J1 and send the message as a UI packet. Messages can be up to 80 characters long, and
should be terminated with a carriage return or line feed character, similar to the Enter
key on a keyboard. The TinyPack will wait for a clear channel before sending the information.
TinyPack was originally created to allow Davis Weather Stations with the Weather Link APRS
adapter to transmit weather data to the APRS network without the need for a full TNC
(terminal node controller). TinyPack can be used by anyone wanting an easy way to
send out AX.25 UI packets over a radio. It is compatible with Arduinos and other micro-controllers which can send serial data. All packet parameters are set using a simple
Configuration program, and saved in the TinyPack chip.
TinyPack is currently available as a replacement firmware that can be loaded into any Byonics TinyTrak3 or Micro-Trak device using a PIC 16F1827 chip. Simply download the TinyPack_v1.4 zip file below, and follow the included instructions to replace the current firmware. To purchase a new TinyPack, just order a TinyTrak3Plus or TinyTrak3 chip from the
TinyTrak3 page, and either update the firmware yourself, or request in the order notes that it be shipped with the TinyPack firmware.
TinyPack_v1.4.zip - This zip contains the firmware and config program to update a Byonics TinyTrak3Plus or Micro-Trak device using a PIC 16F1827 chip.
tinypack.zip - This is the older config program for PIC 16F628A versions
TinyTrak Group at Yahoo! is very active, and many of the posts may be applicable to TinyPack.
Read through the archives for help, or post questions to the members of the group.
You can also send questions via eMail to