PPM Encoder won't power the Spektrum receiver

I am not getting power from the encoder to the receiver (at least no lights or communication).


I have found that in some instances there is not enough current available from the standard USB connection, when using the PPM encoder and receiver with the Pixhawk, to power the Pixhawk, GPS, and telemetry radio as well as the PPM encoder and the receiver. All the components would power up except for the R/C receiver.

So I built myself a custom USB cable that supplies 3 amps to the Pixhawk USB connection and the receiver issue went away.


Did you solder jump SJ1? By default the PPM module will not pass power to the receiver. The SJ1 jumper passes power to the receiver.

Edit: Just watched the video again and it looks like you have not soldered the jumper. SJ1 is opposite from the red LED.

Seriously??!?! I will do that and let you know how it goes! Thanks for answering my inquiry, regardless!

Thanks Tim_D, you were right, and now I can move on to programming the Radio channels on my PixHawk! You rock!!!

Ray Anderson

same problem here, I had my ppm encoder sj1 pre-soldered , pixhawk is powering the ppm encoder but as soon as i am connecting to the receiver with other end of ppm encoder, the light of ppm encoder stops blinking and if i remove it again it starts blinking. Please help

Make sure that you are getting enough voltage out to the receiver.

Perhaps you are getting 5v and only need 3.3v?