Electronics question: automating garage remote dongle (not the motor itself)

My shared garage has an electrical garage door. I live just upstairs the door, so I can open/close it from within my appartment.
To automate I’d hook up one of my garage remotes to an esp and short out the button when I want to open.
Can someone tell me what’s the best way to get about doing this?

I don’t know too much of electronics yet. I’m guessing to simulate a press of the button I’ll have to apply ground or 3.3v to one of both sides of the button.
How would I go about testing this?
I have a decent multimeter, but I’m kind of afraid of the magic smoke and I have no clue really what would be the best approach.

Use your multimeter to see if one of the pins on the button matches to the “-” side of the battery the remote uses. Then also see if the voltage across the button drops to zero when you press (which it should almost certainly do). If both are true, then yeah, grounding both sides of the button (or just the side that isn’t already grounded) should trigger the garage door. Make sure you tie the ground of your ESP and the ground on the remote if you go that route.

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Thank you for your clear help

it does work; i found one side had continuity to the ground, if I connect the other side to the ground, I hear the garage opening.
I think the normal switch platform would allow me to send current, but that’s not what I need.

After some searching, I believe I have to interrupt the circuit using a relay or an optocoupler, and it seems optocouplers are better. So I’ll have to buy those and see where that leads me.

What’s the voltage of the other side of the remote button? With it being battery powered, it’s possible you might be able to control it directly with your ESP. The biggest risk is if it’s over 3.3V, you could damage your ESP. I’ve done something similar for a fan, but not with ESPHome.

Otherwise, a simple relay would probably be the easiest. Wire it such that when the relay is closed, the two button pins get shorted simulating a button press. Then you could make a cover in ESPHome and have it close the relay for a short bit whenever you want to open or close the garage door. That’s what I did with my garage door, albeit at the actual opener (simulating a wired button press).

Edit: Also, an optocoupler isn’t want you want. That would be if you want to SEE a button press but keep your ESP isolated, not simulate one.

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