N0QBH PIC Packet Radio Decoder
Outputs to a computer or GPS

Building your own packet radio decoder isn't as hard as it sounds.
This project uses a PIC 16F62x micro along with a MX614 1200 baud modem IC to decode AX.25 digital packets used by amateur radio operators.
The vast majority of the circuitry is inside these two chips and with the addition of a few other parts, you're set.
There are two versions of firmware for this decoder.
The PC version outputs serially to a computer and will display the local packet radio traffic.
The GPS version will plot APRS stations on a GPS.
Downloads include software, schematic and instructions.

GPS version also plots Mic-E compressed

Packet Decoder Features
1200 baud AX.25 decoding - works great with APRS.

Displays up to 208 bytes of any packet (PC version).

Received packets output serially at 9k6 baud (4k8 GPS version).

Operates on less than 3 mA of current using a 9 volt battery!

Uses audio input from nearly any receiver.

GPS version also decodes compressed Mic-E position reports.

The completed packet decoder built on a PICProto18 pcb
Garmin GPS displaying data from the GPS decoder.

A source for the MX614 modem chip

Questions and inquiries can be sent to: webmaster

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This page was updated 2-8-08