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
RT @TinkerGen_: "The Tinkergen MARK ($199) is my new favorite starter robocar. It’s got everything — computer vision, deep learning, sensor…
Monday
DIY Robocars via Twitter
Monday
DIY Robocars via Twitter
RT @roboton_io: Join our FREE Sumo Competition 🤖🏆 👉 https://roboton.io/ranking/vsc2020 #sumo #robot #edtech #competition #games4ed https://t.co/WOx…
Nov 16
DIY Drones via Twitter
First impressions of Tinkergen MARK robocar https://ift.tt/36IeZHc
Nov 16
DIY Robocars via Twitter
Our review of the @TinkerGen_ MARK robocar, which is the best on the market right now https://diyrobocars.com/2020/11/15/first-impressions-of-tinkergen-mark-robocar/ https://t.co/ENIlU5SfZ2
Nov 15
DIY Robocars via Twitter
RT @Ingmar_Stapel: I have now explained the OpenBot project in great detail on my blog with 12 articles step by step. I hope you enjoy read…
Nov 15
DIY Robocars via Twitter
RT @DAVGtech: This is a must attend. Click the link, follow link to read the story, sign up. #chaos2020 #digitalconnection #digitalworld ht…
Nov 15
DIY Robocars via Twitter
RT @a1k0n: Got a new chassis for outdoor races (hobbyking Quantum Vandal) but I totally didn't expect that it might cause problems for my g…
Nov 11
DIY Drones via Twitter
First impressions of the Intel OpenBot https://ift.tt/36qkVV4
Nov 10
DIY Robocars via Twitter
Nov 9
DIY Robocars via Twitter
Excellent use of cardboard instead of 3D printing! https://twitter.com/Ingmar_Stapel/status/1324960595318333441
Nov 7
DIY Robocars via Twitter
RT @chr1sa: We've got a record 50 teams competing in this month's @DIYRobocars @donkey_car virtual AI car race. Starting today at 10:00am…
Nov 7
DIY Robocars via Twitter
Nov 6
DIY Robocars via Twitter
RT @a1k0n: Car's view, using a fisheye camera. The ceiling light tracking algorithm gave me some ideas to improve ConeSLAM, and having grou…
Nov 5
DIY Robocars via Twitter
RT @a1k0n: To get ground truth I measured the rug, found the pixel coordinates of its corners, calibrated my phone camera with my standard…
Nov 5
DIY Robocars via Twitter
RT @a1k0n: @DIYRobocars is back in December, but outside. Time to reinvestigate ConeSLAM! I rigged up a quick and dirty ground-truth captur…
Nov 5
More…