Simple room temp sensor + display?

Hardware
1

I found this cheap temp sensor with e-ink display that is super simple and beautiful:

https://m.banggood.com/MMC-E-ink-Screen-Digital-Thermometer-Hygrometer-Temperature-Humidity-Sensor-from-Xiaomi-Ecosystem-p-1251682.html

But it doesn’t have any way to connect to HA! Has anyone found anything similar but with some way to connect to HA to report the data in addition to displaying it?

2

If you have a spare Pi, you could try a Switchbot Meter with this.

3

This looks perfect! Thanks!

Can I run the software on the same Pi I’m using to run hass.io? Or does it have to be a separate one?

4

If it’s a standard installation of a Home Assistant (Hass.io), you’ll need to use a second Pi. The script needs Python libraries which are not included with Home Assistant (Hassio), and it isn’t possible to install additional libraries. Buy, you don’t need to break the bank. Just a Zero W with a small SD card is fine.

5

Great, thanks!

6

There is a HA integration for those sensor: https://github.com/custom-components/sensor.mitemp_bt

7

Even better! I was just looking at the wrong model I guess. Looks like these are hard to find for sale online though - but so good looking.

Thanks!

8

Hi @Coltuxumab

Could you please give an update, whether you got it working and which approach did you use?

I am already using the mitemp_bt component with the LYWSD03MMC model which is even cheaper (about 3-5$ on AliExpess) and it works perfect with Hassio. But the display is not that good and data is only updated once every 10 minutes. So, I have just ordered the new MMC model like yours.

Thanks :blush:

9

I actually kept doing research and realized that I need to wait for an American version before buying. The current version is meant for China and only shows Celsius. It also apparently can’t account for daylight savings time accurately so the time is often off by 1hr.

I emailed xaomi USA and they don’t yet have plans to make a US version. Hopefully soon…

10

Hi @Coltuxumab,

What specific needs do you have for a US version?

You can switch to Fahrenheit from within the Mi-home app.
The time is logged and shown by HASSIO which is your local time.

Kind regards,
Ghassan

11

That’s good to know! Didn’t see that written elsewhere.

I realized that if I’m going to have a display on the device itself, it should have the time displayed. So I decided on this one: https://m.aliexpress.com/item/4001017593828.html

Thus, it relies on the internal clock which is apparently 1hr off half the year no matter what you do. Have you found differently?

12

I don’t know this model but I Googled it and found this: https://c.mi.com/thread-2126975-2-1.html

Looks like you can do a work around during summertime by manually choosing a time zone instead of the automatic setting. In this case, you select a time zone that is one hour earlier than your actual time zone.

Hope this works for you😊

13

Hmm maybe I’ll give that a shot!

14

UPDATE: It was delivered and setup is complete! It’s now reporting humidity and temp to Hass.io without issue! Going to give it a few days in case there are any issues, then purchase a few more for other rooms. Too bad they take 1+ months to ship.

Edit Jun2021: still working beautifully. Just need to open the Mi app twice per year to get the time to change for daylight savings.