Control a Circuit Boards Push Button with Arduino

Hey All,

Hopefully a simple one. I have a circuit board, in this case its a HDMI switcher, 3 in 1 out. It has a push button on it (3.3v). Its non latching, so each press of it just cycles which HDMI input is selected.

I want to be able to use Arduino to control that pushbutton, instead of actually pressing the pushbutton.

So im thinking remove the push putton from the circuit board, solder on two cables to either side of the old push button.

Now I just need to make/break that to actuate what used to be the switch. First thought is a relay, just pulse it off/on quickly to simulate a button press.

But is there a way to do it directly from Arduino without a relay?

Thanks.

You need more knowledge of the circuit of the switcher - voltages etc -?if you use anything other than a relay .

An opto isolator with transistor output might do it .

hammy:
You need more knowledge of the circuit of the switcher - voltages etc -?if you use anything other than a relay .

An opto isolator with transistor output might do it .

I figured might need a bit more info. It looks like a 2 way 4 pin push button. so two contacts either side which are closed, voltmeter accross them gives 3.3v, operating the pushbutton opens the circuit, its the same action on the other side of the push button on its other two contacts. Although it may only be using two contacts anyway as cant see the circuit board traces.

I suppose though a relay is just as easy/elegant as any other solution for this, and less prone to error on my part.

Can’t go wrong with a relay !!

Sounds like it’s one of those switches which has pins on one side commoned , and the other side commoned. You could check that .

It would be nice to know what current passes through that switch ( can you see a pull-up )...assuming its small.. If you wired an opto across it - collector of the transistor to the 3.3v side and emitter to 0v.
Then just power the led side from the Arduino on a digital output , just as you would power any led.