[solved: only when using dc to power] Two switch inputs into a Shelly 1

I have a shelly 1 which i’d like to use as a detached switch into Home Assistant.
Thing is i need to read 2 switches.
Am i able to use GPIO3 or 1 exposed in the flash/debug port in addition to the GPIO5 in the main body?

Has anyone tried this? i’d rather not waste a shelly 2.5 on reading two button presses.

I don’t think so as I believe the GPIOs are connected to the supply voltage.

Thanks for the info, i’ll meter it out and see what i can find.

When they first came on the market there was an online review that alerted me to this, but it was a while ago.

I think it was this one Is the Shelly 1 better than the Sonoff Basic? - YouTube

yup, that’s is correct.
I had hoped maybe with version 3 of the shelly 1 that would no longer be the case. but it does appear that GND on the serial port is directly connected to L.
So running of DC this will be fine, running of AC it will AT BEST burn traces and destroy the shelly. At worst it will kill you and everyone you care about in a fire.

Shely 2.5 it is! :0)

thanks for everyone’s replies!

i guess it is possble maybe to configure gpio3 as high and use that as the input for gpio1 through a switch but i have a 2.5 on hand so i’m just going to RTFM and do that.

You might be able to use the Shelly temperature sensor addon module for your extra switch according to this github post: Add support for the external input of the Temperature Sensor AddOn for Shelly 1/1PM · Issue #1079 · esphome/feature-requests · GitHub

The Shelly module has an isolated power supply and buffer for the exposed GPIO pins to make it safe but it costs almost as much as the Shelly 1 so a Shelly 2.5 is probably cheaper.

i did have a look at that, i couldn’t see how it worked. now that i look at the picture a bit more i see it piggy backs on top and plugs into the serial port. that would begin to get close to max size for me.
and as you said, i might as well use a 2.5

since the shelly 1 pro has come out i’m seeing good deals on the original gen. so i’ll pick up a few more then trying to electrocute or burn my house down :smile: