Wireless low power battery powered long range home assistant node

[Samurai]

Hi there,

I am looking to create some wireless battery powered low power devices that I can place around my property and hook up some sensors, and have the readings transmitted back to my home assistant receiver device.

For example:

- I want to place some temperature sensors around the property and have a reading every 15 minutes.

Criteria:
- range at least 50m through the garden and into the house (brick).

- preferably powered by a 3,6v battery for at least 1 year.

- wireless technology can be anything, since I have not yet made the receiving node.

Is it too optimistic to think that such a device can be made for max 5 euro including sensor but excluding battery)?

This guy made a nice solution using zigbee, but the board alone exceeds the budget by far - but just to show the concept: https://tutoduino.fr/en/tutorials/esp32c6-zigbee/

Any suggestions for parts and technologies?

[Felix]

Maybe it's doable with a ESP+Zigbee, if you put in the leg work to wire up everything.
But I will say anything in the few $ range will require a bunch of effort on your part.
As far as battery life, it will need to be carefully coded to sleep your nodes to an absolute minimum. But keep in mind anything ESP/wifi will take a hit whenever it wakes and connects to wifi, and this is impactful on small batteries.

I stick to my Moteino creations whenever it comes to low power. I have documented real implementations where Moteino based/derived nodes thrive in the most extreme situations for years and years without intervention, on small batteries such as CR123A.

For perspective, in one instance the client came to me to redevelop a solution that was ESP based, same battery type, but the ESP could not keep up pace and hold a charge for more than a few weeks.