Using a SPST switch between signal

Other Hardware General Electronics
1

Hi,

If a want to put a switch between a signal that controls a relay, do I need to bind the switch to ground also?

Consider this: I write a high value on digital pin 7, causing the relay to power a 12V device.
Can I put my switch between the pin 7 and relay, without the need of any resistors? Or do I need to set the pin mode on pin 7 to pullup? Or do I need to connect the switch to ground, like this:

See attachment for complete circuit:
http://forum.arduino.cc/index.php?action=dlattach;topic=360474.0;attach=144290

waterpump.jpg

2

A switch is a break in the line. Unless you are grounding the switch case (usually because it is metal) for safety reasons you don't need a ground.

3

Thank you. So my circuit does not need any changes in regards to the switch?

4

Where are the specs of the relay module, it will depend on that.

5

I'm using the 4 channel relay module from Keyes:
http://www.kjell.com/no/image/Product_237168no/full/1

Haven't been successful at digging up any documentation on it.