Servo tremor while RFF900 is ON.

Hi community.
I have an issue with my setup and RFD900.
When the RFD900 in ON (27-30 dbi of power) the servos are tremoring and when RFD900 is OFF - all working fine.
Somehow RF noise affects to the servos or servo wires or maybe APM 2.5 and there is a tremor. I think that this is the RF noise because when I decrease the RFD900 power to 25 dbi the tremor almost gone and also when I put the RFD900 a little bit far away (~0.8m) from the APM and servo wires the tremor also almost gone, so I don’t think that this problem caused by wrong wiring or powering.
RFD900 has a separate power 5V. I tried to power it directly from the APM (5.3V) but the result was the same. Each servo gets its own power and only the signal wire connected to the APM.
My main assumption that the RF noise is affects to the servo signal extension wire and than two cases:
- the RF noise distorts the PWM which comes from the APM to the servo 
- or the RF noise affects to the APM and the APM generates a bad PWM
I also tried to connect to APM a servo with a wire about 10 sm, but the same effect.

Some videos:

https://www.youtube.com/watch?v=p0c4ieVVbZY

https://www.youtube.com/watch?v=5C0SxhVWRso

https://www.youtube.com/watch?v=P-EBhLPTP_4

Performed some extra tests.

If to place a servo which connected to a different, separate receiver - the same tremor, so it is definitely RF noise from the RFD900 affected to servo or wires from servo. If fully to cover the servo by a thin aluminium foil the tremor is gone or almost gone even at the close distance from the modem. Also I’ve been tried various settings of RFD900, nothing helps. The only way is to place modem at least 1 meter from the servos and cables, but my plane not allow to do this, or to make a super screening of the servo.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • These can help http://www.radioshack.com/product/index.jsp?productId=2996360

    I have the same issue I am going to make a wire out of a shielded usb cable and see if that helps. Will post results. 

  • I also have a small (foam) plane and when using the RFD900 it made the nearest servo twitch. The only solution for me was to turn the power down on the RFD900 from 25 to 17 (in my case). Just lower your power by incriments of 1 until it stops.

This reply was deleted.

Activity

DIY Robocars via Twitter
May 15
DIY Robocars via Twitter
May 14
DIY Robocars via Twitter
May 13
DIY Robocars via Twitter
RT @f1tenth: Say hi to our newest #F1TENTH creation for @ieee_ras_icra next week in Philly. It’s going to be huge! 😎 🔥 @AutowareFdn @PennEn…
May 13
DIY Robocars via Twitter
May 11
DIY Robocars via Twitter
May 8
DIY Robocars via Twitter
RT @SmallpixelCar: Noticed my car zigzagged in last run. It turned out to be the grass stuck in the wheel and made the odometry less accura…
May 8
DIY Robocars via Twitter
RT @SmallpixelCar: Test my car. RTK GPS worked great. Thanks @emlid for their support. https://t.co/EkQ6qmjmWR
May 8
DIY Drones via Twitter
RT @chr1sa: @kane That's @diydrones circa 2009. Still have a box of those Canon cameras that we used to strap into planes, just like this.…
May 3
DIY Robocars via Twitter
RT @chr1sa: Our next @diyrobocars race is going to be outside at a real RC racetrack in Fremont on May 28. Fully autonomous racing, head-to…
Apr 30
DIY Robocars via Twitter
RT @f1tenth: Our Spring 2022 F1TENTH course @PennEngineers is coming to an end with a head-to-head race as a big finale. So proud of our st…
Apr 26
DIY Robocars via Twitter
RT @DanielChiaJH: I wrote a thing! Throughout the development of my @diyrobocars car I've been using @foxglovedev Studio to visualize and d…
Apr 23
DIY Robocars via Twitter
RT @SmallpixelCar: My new car for high speed. Low body, everything ( @NVIDIAEmbedded Jetson Xavier NX, @emlid RTK GPS, IMC) under the deck…
Apr 23
DIY Robocars via Twitter
Apr 21
DIY Robocars via Twitter
RT @f1tenth: F1TENTH Race training setup @PennEngineers for our upcoming ICRA2022 @ieee_ras_icra competition. @OpenRoboticsOrg @IndyAChalle…
Apr 21
DIY Robocars via Twitter
RT @fatcatFABLAB: Proud to be hosting a restarted DIY Robocars NYC Meetup April 26. Come by if you want to talk about and race self-driving…
Apr 17
More…