Sonoff T1 3 Button Question

Hello, I am wondering if I purchase a Sonoff T1 3 Button switch can I use only two lines and use the 3rd button for something else in home assistant?

I am installing it in a 2 gang socket (2 light swtiches) but thought I could use the 3rd button to control other things in HA. I’m sure it’d be fine but I wanted to make sure it would work before ordering. Thanks!

Yes! This is definitely possible.

There are a few ways to do it, I’ll assume you’re using it reflashed with the tasmota firmware first.

The easiest way to do it is just never wire anything to the third relay and let it function as normal (turning the relay on/off with the switch, just not connected to anything) and use the status it sends back to HA (over MQTT) to control things. This is how I’m doing it to have a 2 button T1 control one hardwired load, and one “virtual” load in HA.

The other way would be to use tasmota commands to reprogram the third button to do something different, such as publishing a custom MQTT payload or something.

Thanks for the info. I am looking at the US version and it seems like it wouldn’t cover up my 2 light switch panel properly. I know Dr. Zzs has a video about gluing it to an empty 2 gang cover to make it look a bit nicer, but is there a cleaner option that you know of?

The US version does not act like a normal outlet…

Here are 4 photos (as 1 album) that I just took showing how the the switch is actually mounted, since it’s easier to show then describe.

There’s a frame that gets screwed into the gangbox, then the switch itself clips into it. If you had a gangbox with more than 1 gangs, you would have to make something custom like Dr Zzz did. All of the instances where I used the T1 are in single gang boxes though, so I don’t have much personal experience there.

I see. I am in Canada so we usually end up going by US standards for most things. Not sure which to go for here would EU work? it looks a bit larger.

US Single gang boxes are 4x2.5 inches I believe, while the UK boxes are 3.4x3.4 I think (sonoff T1 UK specs), so that wouldn’t quite fit either. Someone who actually has access to a EU electrical box might be able to correct me if I haven’t got that right.