If I was to add limit switches to my diy Cnc using pins 9,10,11 and 330 ohm resistors is there any thing else I need to do. All I want them to do is shut off the motor if they are closed.
Do I wire them up Nc or No. it's just a protection circuit from machine damage
It is safer to use a pull up resistor (between 5volt and pin), and the switch between pin and ground.
No direct 5volt on the wiring that could short out to ground.
With a normally closed contact, you now have a normally LOW on the pin, and a HIGH when the limit is reached.
Leo..