I recently bought a simple SMAKN 315MHz RF receiver and transmitter, and I got everything working so that the transmitter transmits the value of a joystick, and the receiver receives that and uses it to set the analogWrite() of a motor on a PWM pin.

However, the moment the motor turns on, the receiver just weakens tremendously. At that point it only gets a message when I stick the receiver right against the transmitter. I’m powering the arduino and motor with a 3.7v LiPo battery btw.

Any help? I’ve tried with a 9V alkaline and a 9V adapter and nothing significantly changed.

  • What kind of motor? How is it wired?
    – Majenko
    Aug 29, 2017 at 12:22
  • @Majenko Just a simple brushed motor, it doesn’t even matter if the motor is on the transistor controlling the speed or just plugged into voltage and ground lines with a resistor, the receiver immediately will stop working Aug 29, 2017 at 12:29

1 Answer 1


That behaviour is to be expected. Motors are very noisy and cause massive amounts of interference in radio signals.

The best thing you can do is to try and suppress that interference. For this you will need three 0.1µF (100nF) ceramic capacitors.

One capacitor is connected between the terminals of the motor to reduce noise transferred down the wires (wires make good antennae). The other two connect between each of the terminals and the metal body of the motor.

The metal body of the motor then becomes a shield to trap the noise.

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.