Hi Guys, Ive been using my 3 axis radian setup with a spectrum system with great success. I now have a spare mx20 so i wanted to use the newer radio. Ive been able to set it up and everything works ok including the zoom and camera stop/start on my cx760. But i am getting small jerky movements on the tilt and roll with no real pattern to it-even when i move the zoom stick(have it on throttle) the roll or tilt will jitter-watching the input monitor i can see the right hand side channels move when i move the corresponding channel on the left side of the monitor. I can put the throttle/zoom to a certain position and it will roll and tilt on its own erratically. Have i got a radio set up problem?? It does seem to me that the radio could be triggering this-dont know what im missing! Any ideas greatly appreciated. Cheers Matt
Hi Matt: Do you by chance have a second MX-20 controlling the frameset (hub/booms/motors)? Is it powered on too? If so there may be interference between the two -- if nothing else, GR-24/16's both transmit telemetry data, so if you have two of those active, there can be problems. But, as you say, it certainly sounds like interference. It seems counter intuitive, but do you still see this problem if the transmitter is 10 feet away from the receiver? If you're only a couple of feet away you might be overloading the receiver, perhaps? The inverse-square law does nasty things with radiated power when distance tends to zero. Can you also describe the power set up you have for the gimbal? Andy.
Hi Andy, Thanks for taking the time to reply. Im all fixed now-i did a firmware upgrade on the second mx20 and hey presto everything is perfect. I do have an mx20 for the frameset but it was off completely when i had the issues. I tried taking it further away and no difference. I power the rx with a bec and the radians get their power from there. Anyway with everything fired up both radios work perfectly with no interference and the radians and cinestar are working perfectly. Weird that firmware would fix it!! But im not complaining. Thanks again Matt
Hi Matt: Glad to hear that a firmware upgrade fixed it. Just for my education, what version was the firmware and what did you upgrade it to? With the MX-20, I'd found that I had to regress back to 1.003 because I couldn't set SUMO on the version that came with the MX-20 (back in May 2012). Actually, given that firmware really runs the world, I suppose we shouldn't be so surprised that an upgrade fixes things! Andy.
There was one firmware version for the MX-20/GR-24 that caused random changes in the channel signals resulting in machine twitches. Sorry, but I don't recall the version, but it was confirmed by Holger over on .de I didn't mention it in this thread because it sounded like your controller had been working fine on another machine.
Here is the thread. I'm not seeing the problem FW identified by number. http://forum.mikrokopter.de/topic-34986.html
Odd that they wouldn't identify it by number. I have a spare MX-20 so I might dare to upgrade to the latest version. I need to make up a test harness for the GR24 so I can monitor the PWM and PPM outputs on an oscilloscope and see if I can observe any jitter. Trouble is, I suspect jitter would show up better on a logic analyzer that can record longer time periods. Andy.
Don't forget to upgrade your GR24 too. You must use version 33512_gr_rx12_3a70_bf.bin and (version 1v126.bin for your MX20).
Hi Andy My mx20 is now running firmware version 1.120 and working perfectly for all gimbal controls. I didn't upgrade the rx but everything is great. Cheers Matt
That's good to know. Right now I'm in the state of "if it ain't broken (the MX-20 that is), then don't fix it." The GR-24 that won't output PWM as well as SUMO PPM is broken so I will fix it! Andy.