Long ago in a galaxy far far away I built an RC solar plane.
http://www.rasdoc.com/splinter/solar2004.htm
I have a lot of switching power electronics on this plane and it was before 2.4Ghz radios were common. The power electronics caused interphereence with both 50 and 72Mhz RC transmitters.
So I made a system where I replaced the module on the back of my JR transmitter with a little CPU that read the PPM signal and used a maxstream 900Mhz radio to talk to the plane.
The plane could also send down telemetry on the same channel.
Today I see a lont of work being done to add telmetry to things like the custom turnigy 9x builds etc... yet they still use two radio systems, a (usually) bi-directional telmetry system and a separate RC transmitter.
So my question is this why not modify the Turnigy so it sends serial commands containing all the info normmaly used in a PPM signal via a serial conenction via a xbee (either 2.4G or 900M version) and have the quadcopter autopilot use that as both telemetry and RC communication?
Then roll the APM pllaner info into the Turnigy and have a simpler system with more capability and less parts?
I spent the evening digging through all the turnigy 9x modifcationt hreads on the net and conceptuall this seems like a simpler solution that what a lot of people are doing with two complete radio systems?
If you switch to 900Mhz bi directional telmetry/controll channel, you'll get longer range than 2.4G and also open your self up to using the really low cost 2.4Ghz wireless video systems?
Any thoughts?
Paul
Replies
I am doing something similar with USB flight controllers and a little industrial PC on the ground connected to a 900MHz radio and in the air coming out of the 900mhz radio via serial to a micro which converts my data stream to PPM. I wanted to use a mod5270 onboard but I have a hell of a time coding the easy stuff as it is. I am using the same radio for video, as they also have Ethernet, with good results.