0
\$\begingroup\$

This question already has an answer here:

If I wanted to control several ICs that exceed the current rating of an Arduino 5V supply pin with an external DC regulator (which also would power the Arduino itself), should the ground planes of the DC regulator be be connected to the Arduino GND pins?

\$\endgroup\$

marked as duplicate by Dave Tweed Jun 28 '14 at 1:56

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

1
\$\begingroup\$

Yes.

Not much more to be said than that...

\$\endgroup\$
1
\$\begingroup\$

The "ground plane" can also be considered the "reference plane". Without all devices using the same reference, they will not see the same voltage on other connections.

\$\endgroup\$
1
\$\begingroup\$

What we call a Voltage of 5V is really a Voltage Potential of 5V. The difference is that a Voltage Potential is the difference between one Voltage Level and another Voltage Level. 5V can be +3V to -2V, +12V to +7V, or 5V to 0V. They are all the same. Ground is also a relative term. It's the lower voltage level used as a reference to the higher voltage level (or vis-versa when using negative voltages).

Since the voltages are relative, two arbitrary voltage sources could be different. To make them work together, you tie the ground reference voltages together, so that all the circuits have the same reference.

\$\endgroup\$

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