Brand: XIAOMI Mijia
Modell: YWSD03MMC
CMIT ID: 2019DP8115
Material: ABS+PMMA
Size: 43x43x 12.5mm
Voltage: DC2.5V- -3V
Battery: CR2032
Wireless Connection: Bluetooth 4.2 BLE
Measure range: 0°C-60°C
Temperature display resolution: 0.1°C
Humidity range: 0%一99%RH
Humidity display resolution: 1%RH
Executive standard: QB/WSDJ 2401-2019
Trying to buy 3 but don’t see any discounts 😒
Did you install custom firmware? I bought 3 from last deal still in the box, thinking what to do with them.
Nope, straight outta the box to different rooms.
The custom firmware doesn't allow you to do much more. You can just stop the Bluetooth pinging so often to save battery and also slightly customise what's displayed, but nothing revolutionary.
What's the point of Bluetooth on this?
phone app shows you temperature and humidity history
links to other Mijia devices (such as bedside lamp), to provide temp/humidity for home automation
It can be linked to your home automation (in my case Home Assistant).
Connections to BLE gateway on mi devices like mi lamp to communicate via wifi
FYI this works well but is tiny. Can’t read it unless you’re right up close or using the bluetooth functionality although it takes a second to connect every time you check.
Our round one is at 2/5 battery bars after 18months, been amazing with our child as baby cam does the room and this does our lounge.
Good for hatching chicken eggs in a diy incubator
one thing turn me off about this is the silly face
Easily fixed with a simple firmware flash.
Wow Really, never knew this. Would link to instruction
Shame this isn't ZigBee, it'd be great for home assistant
I just got these up and running on home assistant on a raspberry pi (using the built in bluetooth). Works well - use the BLE Passive module not the official native module that ships with home assistant.
Well that's pretty cool, I'm just about to migrate from the Pi to a NUC - I suppose it would work with that too. Might buy a set and see.
This is the guide I followed:
https://github.com/custom-components/ble_monitor
I think anything with direct access to bluetooth hardware (like a dongle for a NUC if not built in) will work fine.
Tip: If using a USB Bluetooth dongle on the PC, you will get much further range if you use a USB extension cable e.g. a 0.5m cable and connect the dongle to it.
I've got them on Home Assistant using an ESP32 (and ESPHOME) as a receiver
Put one in my car, used it to prove I was right (as usual) that it’s faster to cool my car with the windows down than blasting the A/C, after the car has been parked in the sun during summer.
Sure the A/C feels cool, but the heat takes much long to exit the car, than driving with all the windows open.
Also interesting to see the temperature rocket up the second sunlight hits the unit, compared to being in the shade.
Thank you for coming to my TED Talk. 👏
Thank you proff.
As you seem to like proving theories, have you tested to see which uses more petrol, A/C on or windows down while driving?
Depends on speed and car design.
I’m pretty sure driving with both the windows down and the A/C on uses the most petrol. I sometimes do that that when it gets over 50 inside the car.
Damn it feels good to be a gangster.
If you have 2 put one in a dark car and one in a white car on a hot day parked with the windows up, should be a difference.
And put a tube of cookie dough on the back parcel shelf…
go on ….
Mythbusters have proven this to be a myth. The size of the windows on the cars are what determines which car is hotter.
Depends on whether you turn left or right.
I have an Elantra, so my front and back windows are basically horizontal.
Aliexpress is cheaper at USD $4.10/$4.74 no battery/battery plus GST
https://www.aliexpress.com/item/1005003103188861.html?spm=a2…
Have a set of this, the temperature seems to be more or less correct. The hygrometer is wayyyyyyyyyyyyyyyyyyyyyyy off.
how can you tell?
I have 3 of this and 2 other from a different vendor. I put all 5 in the same location for over an hour. The temperature display are all aligned with differences within 0.5 ℃. For humidity, all 3 of this displayed different values, over 10 from the other two, which give exactly the same value. Since I have dehumidifier at hand I also check its output, the other two and the dehumidifier readings were reasonably close.
I have 5. All show the same within 5%
I have seven and all are very accurate. I checked using a calibrated thermometer. Mine were all within +/- 0.3c. I can't comment about humidity but seem close enough to other brands. Great devices and have one in the fridge and freezer. I get an email if the Fridge is over 3.5c for say 30mins as an example only (using Home Assistant).
I have multiple of these, put them in a fridge, garage and rooms. Also, use the Xiaomi gateway to link them to wifi.
Xiaomi gateway with some other sensors: https://www.ebay.com.au/itm/Xiaomi-Mi-Smart-Home-Starter-Pac…
Put one in the freezer, it activates a new mode on the screen! I’m not kidding.
Yeah, the LED doesn't like being at -18.5c so loses many lines. It returns to normal when taken out and warmed up. The device works fine though in the freezer and reports back to HA.
Not really a deal as they are almost always around AU$25-$30 delivered for 4 of them from the Mijia storefront on AliExpress.
I bought this [one](ThermoPro TP50 Digital Hygrometer Indoor Thermometer Humidity Monitor with Temperature Humidity Gauge https://www.amazon.com.au/dp/B01H1R0K68/ref=cm_sw_r_apan_glt…) from Amazon last week. More expensive but seems accurate. Not sure if multiple devices supported.
https://www.aliexpress.com/item/4001098178650.html
Best price I found so far if you need 2 or more, less than AUD$7 each.
Cheaper when you buy sets, I have a set of three for different areas fo the house. Once you have one you will definitely want a set.