ARINC 429

[birkelbach]

So I have a Tru Trak (Bendix King) Autopilot in my RV. It is interfaced with a Garmin G5 and Garmin GPS 175. This combination requires a switch on the panel to swap between the airdata from the G5 and the GPSS data from the GPS. So I can have heading/alt select mode from the G5 or I can have GPS Stearing but not both. I talked to Bruce at Mid-Continent Avionics (BK uses them for tech support) about an idea that I had about digitally combining the two sets of labels into one ARINC 429 stream to the AP. Bruce said that he couldn't think of a reason why it wouldn't work.

ARINC 429 controller chips are out of reach and line drivers are quite pricey so I was thinking of rolling my own. My problem is that I don't have an easy way to test whether or not what I'm doing will work without actually installing it in my airplane. I obviously don't want to do that (tedious and risky) so I thought I'd ask the brain trust here if they have any ideas on how I could test this, without breaking the bank.