Only three ground pins on the Uno?

Hi, I need to find a fourth ground pin on my Uno, yet it does appear the limit is just three, or is there an unnamed fourth ground lurking somewhere? ........any advise much appreciated
Douglasstrong text

If you can solder or make crimp connections, make a Y cable.

How many GNDs are needed ?

You can also use a solderless breadboard to multiple the physical number of GNDs.

The 2 ICSP headers each have a ground pin. The ICSP headers are the 6 pin (2x3) headers. See a Uno pin out drawing.

thanks Larry, what does a crimp connection consist of, is it merely intertwining two connections together? ....didn't really want to solder on my new kit just yet!

Thanks, where do I view this Uno pin out drawing?


See this PDF:

thanks again Larry, I will try to fit two connections into just one ground pin

Caution: passing current through the Arduino grounds can cause weird problems. Best to connect them to a single ground point close to the power supply. Motors are especially problematic. If using the USB for power you will probably be ok but caution with motors.

What is your project?
Are you using a protoboard or other sort of board to connect everything to?
If you need 4 gnds, it sounds like a protoboard would be the best option.

Thanks... Tom.. :grinning: :+1: :coffee: :australia:

All resolved how, thanks chaps.
I just had to connect one ground to the long ground rail on the breadboard, and then feed off from that. Simple

Too much blood in your caffeine stream..

That's my excuse.. :+1: :+1: :+1:

Tom... :grinning: :+1: :coffee: :australia:

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