Sharing grounds on a PCA9685

I am using these servo driver boards with an Arduino Uno to drive many LEDs. Can I just jump and share the grounds?

I accidentally hooked up the wrong grounds and noticed the LEDs still operated as normal. Wasn't sure if this was safe or I may damage something. I am not currently using any resistors as the board max amperage is not enough to damage them. I am only using the PWM and Ground pins.

If I can, this would clean up the project immensely by reducing the volume of wiring.

HiLetgo 2pcs PCA9685 16 Channel 12-Bit PWM Servo Motor Driver IIC Module for Arduino Robot


You have us puzzled. What do you see as "right" and "wrong" grounds?

Each LED has a PWM pin and the corresponding GND. I mistakenly swapped some of the ground jumpers on the wrong pins so that some LEDs where connected to the adjacent ground pin and not the corresponding ground pin.

I noticed that they still operated but was worried about letting the magic smoke out.

All ground pins are - or always should be - exactly the same electrical connection.

There are some reasons for connecting the ground in the right place, but not in this situation. The adjacent ground pins are essentially interchangeable. :+1:

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Do you have a DMM?

Tom... :smiley: :+1: :coffee: :australia:

Yes I do. Are you hinting I should see if there is continuity across the GND pins?


Yes , with the power OFF.

Would dispel your doubts.

You have a very powerful diagnostic tool there...

Tom.... :smiley: :+1: :coffee: :australia:

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I tested the continuity per your advise and proved that all the ground are linked together. I was happy to remove all that wiring.


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Could you also take a few moments to Learn How To Use The Forum.

Other general help and troubleshooting advice can be found here.

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