The ER9X hack discussion got a bit off topic when I dragged my FrSky GPS hub project into it. So I've spun-off the hub to this new dedicated topic. I'll use this as a sort of blog on the hub's progress. But before you read much further I recommend reviewing the original thread: http://www.rc-cam.co...827-er9x-hacks/
To help get you up to speed, we've been discussing the Turnigy/FlySky 9X transmitters and the nifty open source firmware that is available for it. Plus, our 9X's have been hacked and now sport the FrSky data telemetry modules. This combination is very affordable but requires delicate soldering and a few hours to perform all the upgrades.
Then in a bit of temporary insanity, I decided to create a custom GPS hub for the FrSky R/C receiver. It would essentially replace the sensor module that FrSky already offers with a smaller, more integrated board that would fit inside the existing receiver. It would include a baro sensor (altimeter) and support common GPS modules (on a tethered cable). And because the hub will run custom software, the telemetry data can be optimized a bit. For example, it will support faster GPS updates and GPS signal quality status.
That's the project in a nutshell. So now we can move on to the nuts and bolts.
About three weeks ago I ordered the custom PCB's. They arrived yesterday and I was able to stuff a set, modify the code to run on the new processor, and test it out. I was relieved to find that the new Hub and the companion GPS works as planned. Also, the hub PCB fits nicely inside the 8-Channel FrSky Rx. So all the scary stuff is out of the way.
Here's a photo of the assembled GPS-Hub and the optional GPS module board. Despite how big the photo makes them look, each board is about the size of a large postage stamp.
At the moment the hub's software only provides GPS data. The baro altimeter code needs to be written. Plus, I think I will add a bootloader as a alternate way to install firmware upgrades. Hopefully these things will be done in a couple weeks. I'll post again as things progress.
Edited by Mr.RC-Cam, 14 May 2012 - 05:41 PM.
Added post #14 info