Help with a push switch

Hi all, I am trying to configure a physical momentary push switch, which, when pushed, will trigger an event in Home Assistant. The switch is just a contact.

I solder this to a ZigBee door relay, which works, but not all the time.

Is there a simple relay(?) that when contact is closed, will trigger an event in Home Assistant?

Just to be clear, I am trying to connect something to an existing switch, I don’t want a new switch.


Do you need to solder it?
Or you can open your momentary switch, remove electric part, install the magnet and use door/window open sensor like aqara one?

I use a couple of Sonoff Mini R2 modules for just that purpose. I flash ESPHome to them and just use them to detect a button press.

Thanks Steevemann, that look great. Except it needs 110/240v. I deal I need something battery powered so there is no power.

Sadly not. What I have done so far is use a door sensor and solder the switch to bypass the reed switch. This works, but not all the time.


IKEA has a few options that is solder free.

IKEA Tradfri ON/OFF Switch E1743 Zigbee compatibility (

IKEA Tradfri Shortcut Button (White) E1812 Zigbee compatibility (

IKEA Styrbar Remote Control (White) E2001 Zigbee compatibility (

Thank Hellis81 - That’s not quite what I am looking for. I have a push button switch, I don’t want to replace this. I want to wire this to something that will trigger an event in HA.

You can use an ESP then.
I find them more reliable than ZigBee

Information that was not in your first post. You said to connect to an existing switch, which implies a switch in the wall with power behind it.

You don’t want WiFi because it would either be on all the time and suck your battery. Of if in deep sleep mode, it has to log on to the network when you press the button and that can take a second or two.

Your only other choices are Bluetooth, Zigbee and 433MHz buttons. But for any of these you need a dongle or bridge. The easiest to hack would be the 433MHz switch.

Now, why not tell us what you are trying to do.

Cheers for your help; sorry if I wasn’t clear.

This project is all about Door Bells! I have a push-button bell switch, it is actually the bell push from an old London Bus!


It functions as a momentary switch. So when someone presses this, I want HA to kick off a routine. I can get the HA side working, but I am looking for something that, when contact is made, fires a signal to HA.

I have tested this using a ZigBee door sensor and bypassing the reed switch. It works but isn’t very neat or reliable.

I hope this makes more sense.

I am looking at an EPS01, as kindly suggested by Hellis81, but I am not yet sure how to set this up.

Cheers again


You can make a button sensor from any ESP device flashed with ESPHome. That part is simple. But you want a battery-operated device, and the ESP device is a poor choice. In order to respond to a button press, the ESP has to be running and connected to your WiFi. The ESP-01 draws about 80mA in it’s normal state. You could put it into deep sleep to reduce the current to 1 or 2 mA. The button would simply short RST to ground momentarily which would wake the EST from deep sleep, and basically reboot it. It would take it a second or two to connect to your WiFi for Home Assistant to see the button (a binary sensor actually), then it would go back to sleep.

I bought some of these on Ali Express:


They put out a 433MHz signal when pressed and the batteries have lasted for a few years. I have a SOnoff RF Bridge that detects the button presses and I use Nod Red to handle the button presses. Node Red can then present the button press as a binary sensor.

This is cool. Could you also:
a) show us the back of this thing
b) a photo to show how you wire up to your doorbell circuit, and the wall / switch box around where you plan to install this button.
c) a diagram / schematic for the wiring of your doorbell circuit - this button, the power supply, the bell, which wire goes where, at what voltage, etc.
d) what do you plan to use the “event” for? and how?

I believe the discussions so far does not yet have any clear direction, because we are not sure what we are dealing with. So maybe with the materials you’d provide per above, people around here would have a better picture on how to help.

You said you are using a zigbee door sensor… but does not work all the time… so which door sensor exactly? maybe the real problem is on the sensor and/or your zigbee mesh network, and maybe we should focus on that instead.

my 2 cents… happy hunting!