Here at home, we lost all the garage door remotes. Since I had a spare Sonoff RFR3 lying around, I decided to modify it to be able to activate the garage button. But to do that, I had to make some modifications, as you’ll see later in this blog post.

Sonoff operation

The Sonoff connects to power via live and neutral wires and it controls devices by interrupting the flow of electricity through these wires using its outputs:

However, to simulate a button press for the garage, I need to modify the outputs to have a dry contact.

To make this modification, I had to cut the following electrical traces marked in yellow and solder the jumper wire marked in blue.

To simulate human touch, it’s necessary to configure the option Inching in the eWeLink application, with a ON state with a duration of 0.5s.