Wiring Arduino and transistor with ground as switch

Projects General Guidance
4

MountainGuy:
Connect 5+ --> | switch | <--------pin 7, then pin7 with a resistor to ground.

You don't have to use an external pull-down resistor: the Arduino has internal pull-up resistors. Just connect your switch between pin 7 and ground, and add the line

pinMode(7, INPUT_PULLUP);

to your setup.

Note: when the button is pressed, digitalRead(7) will return 0, and when the button is not pressed, it will read 1.

Pieter

P.S: It's MOSFET, not Moffset :wink: it stands for Metal Oxide Semiconductor Field Effect Transistor. MOS is just the materials it's made of (Metal for the Gate, then an insulating Oxide, and finally the actual Semiconductor), and FET is the type of transistor (current flow depends on the applied electric field.)