Any advice on how to make a remote button presser?

Hi everyone, I am new to vancouver hacker space.

I am trying to make a remote button presser, i would like to control the device to press a button remotely, so that i can restart a computer physically from far away (I know we have stuffs like IPMI to do the same thing properly, but i would like to make a microtroller project just for fun)

I understand that i can program a microtroller to send out signals, but what components I should attach to the output of the microtroller to make it achieve the functionality of pressy a button? a motor or something? Can someone please give me some advice? Thank you very much in advance.

Hello and welcome!

There are many ways to do this, I would say the easiest and most reliable is wiring a relay in parallel with the button and using the microcontroller (uC) to activate the relay.
Most buttons just connect two wires together, so if you use a SPST relay, you can wire the output to each side of the button, turn the relay on and bam you just touched the button.

For starting off you can buy premade relay modules 1-RELAY DIGITAL MODULE 5V
https://arduinogetstarted.com/tutorials/arduino-relay
If you want to go fancier the current running through the button is pretty small, so you can use a small signal or a reed relay, which means you wont need a transistor to drive it. Look for something with a coil current of under 15ma and it will work straight off an uC pin in most cases. Be sure to put a flyback diode reverse biased to dump the energy from the coil safely so it doesn’t blow up the uC pin later.

Option B if you want a more mechanical way to do it is to use a hobby servo, MICRO SERVO MOTOR SG90 / 9G 180 DEGREE
you connect it to a 5v supply (needs to be an amp or two capable, so you usually cant drive it off the uC’s 5v supply, but you should connect the grounds together) and connect the signal wire to a PWM capable pin on your uC, adjusting the pwm frequency will move the servo position, you’ll have to make a finger pusher dohickey but hey we have 3d printers and laser cutters. https://docs.arduino.cc/learn/electronics/servo-motors
Servos can be useful for all kinds of things: 'Littlebits' 'Arduino' knife-wielding tentacle - YouTube

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There are a variety of Arduinos that are able to emulate keyboards. It might be simpler to remotely trigger a few keystrokes using that method than to use physical motors.

Thank you so much! i will try those things.

thank you for this idea. it will be useful when i run into a situation which i need to control a keyboard. however, in my case, i will need to do a hard reset by pressing the power button, the computer freezes in a way that any key board input is not responsive.

There is a commercial product you can use for inspiration: battery-powered, wireless capable mechanical switch pusher: https://www.amazon.ca/SwitchBot-simple-switch-smart-White/dp/B07B7NXV4R