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 using the Flyton LRS 433 mhz long range module and RX with my Turnigy 9x. You can configure the RX to send a transparent low baud rate serial link along with the PPM signal.
http://diydrones.com/profiles/blogs/openlrs-firmware1-10-with-trans...
details
http://forum.flytron.com/viewtopic.php?f=7&t=294
I want to either loose the xbees or RC transmitter. I need to try the joystick mode through the xbees.
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.
Very cool idea. I wanted to do the same thing- 1transmitter, 1reciever, ALL the data in/out. My concern was bandwidth in the Xbee system. I am using the 2.4gHz turnigy 9x too, 900mHz Xbee, and will use the new 1.3gHz for FPV and photos. I'd love to be able to integrate all of these into one system. I don't have alot of radio expertise- enough to be dangerous as it were. Where to start? I have almost nothing to offer but enthusiasm.
Take a stab at it! Last Friday I went the complete opposite direction and flew without an RC Tx. I tried out the joystick only functionality of Mission Planner on my APM1 quad using APC220 modems. Using a Logitech 3d pro joystick, there are enough buttons to set every AC2 mode available. The whole flying experience with a joystick was interesting, to say the least. :)