Help! Actuator making NOISEE

Hey guys,
I need some help because I’m at my wits end.
Arduino UNO running two actuators (DC Motor and Servo Motor) controlled by sensors.

I can manipulate my flex sensor to drive Servo Motor without ANY cross-talk or noise issues.
However, when I manipulate my soft pot to drive the DC Motor, it drives the DC Motor mostly fine but causes a mess on the rest of the board. (ex - causing my Servo to go haywire)

I first need to isolate whether it’s a coding error, or a breadboard/wiring error. I understand you can’t look over my wiring but I have a thousand times and feel 98% confident it’s correct.

I’m hoping someone would be nice enough to look at my code and tell me if that’s the problem!

_4_29_2015_MPU_FINAL.ino (1.42 KB)

How are you driving the motor (thinks - your using motor shield with PWM and servo)


Do you have a diode in place across the motor to clamp the back EMF? If not, you need that.

You may also need additional caps to stablize the power supply.

I think the problem is almost certainly with the wiring - motors and other inductive loads are trickier to wire.

@DrA - the Servo lib and pwm ues the same timer.


Yes I do have a diode to prevent fly-back. My goal was to see if anyone could point out any coding issues. At this point I’m going to rip everything out and re-wire. Thanks

You will have more people looking at you code if you post it in code tags. There are reasons why people will not download code.


Can you please post a copy of your sketch, using code tags?
Please use code tags.. See section 7,148850.0.html

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

What is the spec of the servo and the actuator and in the circuit can you show how and what is powering them.

Thanks. Hope to help......Tom.... :slight_smile: