@kalininandrey Thanks for sharing!
Tried this with 2 pcs of CCG1 Clear Grass
Working almost* fine,
*One of sensor I’ve placed to far from my Rpi4, so in future I will need to add some ESP32 with ESPHome to link via WiFi, and when CGG1 is out of range, the last available reading is cloned every time as result.
How I can fix it to record something like “unavailable” instead? to be sure that I’m get a correct reading (sensor in range)
Sorry, I’m not a real hass guy, I just mixed together mitemp_bt code with the code by @andras-tim.
I don’t this it’s possible now, this limitation affects all similar sensors (like mitemp_bt, miflora, etc). Maybe you should ask someone on forum who really know how to write sensors.
Anyone else who has the problem that the device stops reporting after some time? After a HA restart reporting continues. Don’t know if its the integration or the device.
A LYWSDCGQ BT sensor works perfect.
I have all 4 Xiaomi devices working perfectly.
Only LYWSD02 is having problems some times but I think there is problem with range. I f I put it closer to ESP32 it works also perfectly.
Does anyone know the update rate of these sensors? Or at what temperature difference they send the new value?
@Roeland54 about 20-25 readings per minute (in case of BLE advertisements).
I came across this topic in search of information on ClearGrass CGD1.
If for someone the question is still relevant, then here is a custom component with CGG1 sensor support (and some others from Xiaomi ecosystem).
I also came across this topic searching for software regarding the cleargrass E-Ink display.
Thanks to alexV for providing the nodejs scripts. That made it easy for me to re-engineer the protocol in go 
Hello,
Did someone tried to disassemble this ClearGrass Wifi? Can you share a high res picture of the inside of the product? Does it have an esp8266? If yes, we might be able to upload a custom firmware to it.
Thanks!
Hi,
It looks like FCC did. Quality isn’t great but it could be a start? It looks it has a few TPs, as well as a couple of headers. I can’t really read the silkscreen from the pics, but one header has interestingly 4 pins… 
Firmware can be downloaded via the mobile app, so it should also be possible to get a copy of the binary. Hope this helps!