APRS OPENTRACKER PROJECTS

Many of us have been keen on getting on APRS and have done it with many types of device. The most common of these for a mobile situation are the Tiny track series from Byron Garrabrant. While they work OK in any of the three variants, the chips are not as easy to procure for the TT2 and TT3 versions. TT1 was /  is available by the net to burn you own if you are able.

N1VG has made a unit that out does the Tiny Track units in every way. It is open source and runs on a Motorola 68HC908kx8 processor of which are easily bought and have the ability to be upgraded over the net or off the local PC.

If you are able to burn your own chips, you burn in a boot loader code that will allow you to down load any updates etc that come available.

More details can be seen from http://n1vg.net/opentracker/ 

Keith ZL1BQE and I have been building variants of the same unit. He initially bought one in from the USA and it used a DIP 16 packaged chip. It ran very well with the Ashtech GPS module a few of us are running. As there is an abundance  of the "Tin Box Maxon" (TBM) DM2550 series radios, we wanted to put the Tracker into the lid of the box.
To do this we would have to make it in SMD. Keith did one on veroboard but it took him quite some time to build it that way. You have to split the existing tracks up into 2  to get the right pitch of the SMD  micro.

I decided to bite the bullet and do a PCB straight off (in my spare time) and build it that way. For a days work, I had designed version 1 on of the PCB and printed, etched it and built it to the extent it was all running in one fell swoop.

The unit fits well inside the Maxon and and initial testing with it allowed me to set up fixed beacons of my QTH without a PC or GPS connected.

The pictures below show progress to date with the units. Click on each item for a bigger view.

The SMD Version 1 Prototype		Board mounted in the maxon, note the temp sensor at the top left.
More detail of the lid mounting.		The PCB overlay.

If anyone wanted to make their own PCBS and have a crack at making one, here are the files in PDF for the Overlay and the Mirrored foil pattern to be printed and ironed on.  Additionally there is the Protel PCB file format.

I will update this more as I go.

73's de Simon ZL1SWW

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