Developing temp/humidity sensor using ESPHome and batteries

ESPHome
1

Hello everyone!

I am posting to receive your feedbacks/suggestions for building my own temperature/humidity sensor (specifically from more experienced people than me about electronics). I really like the learning process of building our own sensors, that’s why I am here.

Objective: In my HA, I want to include a temp/humidity sensor using ESPHome and optimized to work with batteries (Currently, I have my ESP sensor working plugged).

Materials I am originally aiming to use:

  • ESP8266
  • Any temp/humidity sensor (now I am using SHT30)
  • A LiPo battery (maybe something for protect the circuit… no experience here)

Is Lipo the suitable battery here? I wanted to have a battery no bigger than the D1 mini. Based on small research,I think this are the best for this.

Is better to use mqtt in the esphome configuration for this device?

I was thinking the following logic of operation. Is something common to use it in this was? “Every X minutes, make a measurement, post it in mqtt, and go to deepsleep”

Thank you a lot for any suggestion!
Best wishes!
Francisco

2

There are several arguments you have to think about.
D1 mini is power hungry and it has inefficient voltage regulator. Lipo voltage is too high for powering esp directly and too low for built in voltage regulator.
So you need external charging/protection circuit and voltage converter.
Lifepo4 battery 3.2V would be ideal but it’s hard to find charge/protection circuit.
If I had to make small Esp-based rechargeable battery operated circuit, I would go with Xiao Esp32-c3.
The main problem remains, Esphome is not optimized for fast wakeup cycles…

3

Thank you for your response. I will explore the board you are mentioning!

Just a bit of curiosity. Are you familiar how this sensor is made? I mean, there is a home-made way to make this?

Thank you again!

4

If you’re trying to emulate that type of device, I can say pretty confidently that you’re going to get frustrated and spend far more than just buying something pre-made. For instance, I have a TON of the Xiaomi BT temp/humidity sensors scattered throughout my house. There’s no way I could even come close to the price I bought them for ($3?).

2 Likes
5

No I’m not. But I can see it’s ZB sensor, battery powered sensors rarely use wifi.
Also, I agree with Ben, from economical point of view there’s no sense to build RH sensor for home assistant.

1 Like
6

I tend to slap temp/humidity sensors on to usb powered esp devices that have another primary purpose. They are just a “bonus”.

Agree with others on generally just getting zigbee/ble off the shelf sensors.

7

Clear! Thank you!