Above is my serial interconnect drawing if anyone would like it for reference. This isn't a very complicated panel, but I did plan some future upgrades like ADS-B, etc.

Here is the PDF version in full scale version as well http://www.highrf.com/Rockets/Comms%20Block%20Diagram-b.pdf

VP Display Unit and GPS

I've been working on wiring my panel, not just the VP wires, but I decided to be one of those that figures they can do it just as well as the pro guys and am wiring *all* the wires in my panel. Ever counted how many wires just the Audio Panel has, not counting power and grounds :).

In the process, I'm also wiring all my serial interconnects. While I was doing this, I was verifying what goes to where and making sure that I had maximum flexibility going forward as Im going to upgrade to the new Chelton WAAS GPS module as soon as it's available. I learned that CFS released a SB on how best to wire the EFIS to a TruTrak AutoPilot. It seems that in the case of the Autopilot, it want's MAG corrected GPS tracks and not TRUE tracks. In order to provide that, you need to wire the Autopilot, for serial GPS, to COM09 from the Chelton, and not directly from the GADAHRS.

This caused me to wonder about this in regards to the VP DU and it's need for a serial GPS data stream. I dropped Marc Ausman a note over the weekend and he replied right away. In reality, the DU could use either, however, a byproduct of hooking up to COM09 is that you have to wait for the Chelton display to fully boot before it's providing those messages out that port and with the latest certified software, that can take minutes. If you connect the DU directly to the GADAHRS, these messages are available as soon as you have a valid GPS solution, which will happen pretty much instantaineously as long as you have view of the sky.

So, his recommendation is to connect the DU to the GADAHRS in a CFS installation.