Hello everyone, have a nice day,
I have an old computer, I am thinking of making a computer that can be remotely controlled using it. For this, the power btn must first be controlled by the arduino. The button has 4 legs and legs numbered 1.2 does not perform any activity. however, it opens automatically when I touch a screwdriver or a cable on legs 3,4. when it touches any metal surface for a while, it turns off the computer.
how do you think i can control this with arduino signals?
Thank you.

 

You could use a servo driven by the Arduino to mechanically push the button. I did that for a camera trigger.
That could look good, and better if you 3D print a finger for the servo.

Also, an opto isolator as that will be a safe way to keep the Arduino and PC isolated from each other.
But you will need to work out what is switching. Usually a switch to gnd, but it may not be.

 

You can interface to the power on button on the PC. Its typically an open collector interface,
so you use Arduino with output pin configured as open drain, and just connect it to the PC
power button.

I found issuing a logic 0 to the open drain pin for .5 sec was a correct pulse width to start PC,
and several seconds to shut it down. In code I also sensed 12 V supply to figure out if PC was
started or shut down.






Regards, Dana.