Small, cheap, battery powered Smart button

Hardware
1

Hi, I’m looking for a battery powered Smart button with one, or better more, inputs. Can be DIY.

Some use cases: doorbell, light switch, door/window sensor, cabinet drawer/door sensor, detect gas meter counter with a reed Relais and more.

I could use an ESP32 or similar, but I don’t necessarily want WLAN because I don’t want to overwhelm my router. And I’m not sure if the battery life is good or not.

It should be small enough to fit behind a regular (German) wall switch (size of Shelly devices).

Ideally it can run with a 3.6V Lithium batterie (AA size) and I can read the battery level in Home Assistant to create an alarm for low battery.

Summary: I need something like the Shelly Plus i4, but cheaper, battery powered and not necessarily with WLAN.

Any suggestions?

2

The cheapest I have is a rf433, it only has 1 action though. At ali you have plenty of choice at <4EUR

3

But for the RF433 I also need a receiver. And you need a receiver for each transmitter, right?

Something like this?
https://de.aliexpress.com/item/32980820915.html

Then you need something like an Arduino or ESPhome device to forward the receiver signal to HA?

4

Agreed, but you mentioned not wifi :slight_smile:
I tried a sonoff zigbee one (which would also need a receiver) but this is 2x as expensive and for my simplistic use…rather pay half…but this is personal decision of course. The zigbee one has single/double click

5

And long press as well.
The battery life on them is really good.

6

Not mine, which was unexpected … so do read the add & reviews when you buy one (I did not)

7

https://www.shelly.cloud/en/products/shop/shelly-blu-button1

Not particularly cheap at Euro 15, but Shelly make good stuff.

1 Like
8

I think, Bluetooth is not a good solution for me (and for Smart Home in general). And I don’t want to span another wireless network in my home. I think, WLAN, Zigbee and DECT are enough.

I ordered some ESP8266 devices to play around. I try to run them with 3V button cells. Maybe it works for me.

9

Really!?! :angry:
So there are different versions?