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Topic: Motor interference? (Read 2278 times) previous topic - next topic


May 04, 2011, 02:06 am Last Edit: May 04, 2011, 02:07 am by Zinefer Reason: 1
I am trying to get some information about motor interference. What is it exactly? I am working on a project with an Arduino and a serial motor controller and I am worried that if I power the motors, Arduino and motor controller from the same battery I will run into problems. As of right now I have a voltage regulator and the Arduino wired in parallel, the vout on the vreg is going to the vin for the motor controller and vout on the Arduino is powering the serial motor controller. (I have not tested to see if there is in fact interference)

What do you guys think about this setup?

Does a voltage regulator isolate motors from interfering with the arduinos logic?

Does the interference only happen when a motor is being powered from the Arduinos vout?

Thanks ;)


It's generally better to power the motors (through the motor driver) separately from the Arduino. Connecting "vout on the Arduino" (don't you mean Vin?) to the motor controller is not the best way to do it. I recommend:

* Battery to Arduino
* Battery to the motor controller over a separate wire
* Both grounds (Arduino+motor controller) connected together at only point, right at the battery.

The Quick Shield: breakout all 28 pins to quick-connect terminals


What is it exactly?

Voltage spikes caused by the motor inducing voltage spikes in the surrounding circuitry. Also inducing rapid voltage variations into the power lines and upsetting the rest of the circuits.
Power supply decoupling is the cause, there are many techniques of increasing complexity depending on how bad the problem is. One good technique is to have a separate supply (but connect the grounds) Other techniques are discussed here:-


Thank you for the information. I will read over that tutorial. In the mean time:

What do you guys think about this circuit? Will it cause interference?

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