Confused on connecting to the ground

Projects General Guidance
1

Hi everyone!
I'm really confused on what the ground connection while doing a arduino project :disappointed_relieved:
Can anyone tell/teach me what that is and why is it important? Please...

2

The "ground" connection is the negative power supply to all sections that expect such a power supply, all must be connected together. Clearly you must connect the negative of the power supply to "ground" on the Arduino board itself though if it is being powered via USB, the USB connector will do that.

If however you are connecting a servo to it, then the servo must be powered by another power supply, but the ground (negative) of the servo supply must also be connected to "ground" on the Arduino.

3

So should I connect all of my devices in the ground pin?

4

So should I connect all of my devices in the ground pin?

Only those that you want to work.

5

oh ok

Thank you :slight_smile:

6

kaarthik:
So should I connect all of my devices in the ground pin?

It also depends on what the device is, but generally yes.
However, if you are doing anything with current sinking you do not connect the ground.
Read this:-
http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html

7

There are a few things in which you DO NOT connect the grounds the one you will most likely see is RS232 but of almost all the rest you connect the grounds - that's why the ground is often known as the common. The key is that we use voltage (eg 5v =1) but voltage is a measure of the difference on electrical potential between to points we thus need a common point of measurement (the earth/common/ground). More - use Google/Wiki.

Mark

8

Thank you so much :slight_smile:

9

Actually, "ground" is a misnomer. Most projects are not "grounded" in that they are not connected to ground. Physical, dirt, stick a wire in the earth, ground.

What we usually mean when we say "ground" is circuit common. It is the common reference point. All voltages are measured with reference to the circuit common.

10

Actually, "ground" is a misnomer. Most projects are not "grounded" in that they are not connected to ground. Physical, dirt, stick a wire in the earth, ground.

The word for that is Earthed, many people confuse it with ground which is short for signal ground a sort of earth for a signals only.