Hi!

Iv'e gotten my hands on an old broken cnc router.
I'm trying to switch out the old controller and work on a tight budget.
There are 2 problems atm.
TL;DR; versions.

The buttons have internal lightning that requires 12V to light up.
The lightning and switch has a common ground and one pin each.
I'm not sure how to interface the buttons with a 5V MCU?
Especially without risking of burning some component.
Functions wanted, be able to control the light and sense the switch via the MCU


I want to build a PSU that generates a regulated/switched 5V linear output.
I'd rather it would stepdown the 12V from the PSU in the machine thats just been changed.
Whats easiest/cheapest, to buy a 12V->5V psu or to build one?

To make it a little more challenging it's supposed to be able to take cranks from the input, Meassuered to about 10-16V when starting and stopping the motors. And still deliver a stable linear output, just to make sure the MCU doesn't go bananas.

 

Use computer psu. They have 12 volts and 5 volts already.

 

Are the lights led?

They might light up with 5 volts.

 

What CNC router and what/who's is the controller?
Max.