Owner
OwnerTo add a 2-wire (I2C) temperature or environmental sensor, you should select any pin, select the “Temperature (2-wire)” sensor type, and select a subtype (e.g., BMx280), specify the I2C address of the sensor as a decimal number. On the next row (Output2 in this example), you should define a I2C clock pin.
Tomasz
How to get pressure readings in hPa with higher precision? I fail to increase precission and get readings with no decimal point. I would get readings in Pa earlier, but cant revert to that either.
Owner
The firmware uses the standard Zigbee specification for pressure measurements: -3276.7 kPa <= Pressure <= 3276.7 kPa. So, the precision is 1 digit after a decimal point.
Tomasz
That would be enought to me, but how to get such reading? Z2M publishes only intiger number in hPa. How to change that?
Tomasz
Sorry. I’ve misread your reply. All clear now. But would it be possible get readings with 0.1 hPa accuracy, to make better use of BME280 pressure sensor? Would that be possible be adding ScaledValue attribure reporting (the converter seems to have support for that already)?
Owner
But 0.1 kPa accuracy is better than 0.1 hPa. Isn’t it?
Tomasz
0.1 kPa = 1hPa, so 0.1hPa is one decimal more granular. BME280 pressure range is 30-110kPa, thus the standard zigbee range of -3276.7 kPa <= Pressure <= 3276.7 kPa is just too huge, thus lost accuracy. If scale of 0.1 would be applied then ScaledValue would be -327.67 kPa <= Pressure <= 327.67 kPa, if I understand Zigbee spec correctly.
Thomas
How long does the sensor update its value, I try it and it show Unknown in both temperature and Humidity after connect
Owner
The firmware reads sensor’s data at periodic report interval and sends to a coordinator. Some coordinators may change this interval remotely. Please try to disable this possibility in the firmware settings on the Expert tab.
Thomas
I found my mistake, I accidently solder 2 100nF Capacitor to the I2C Line, result in fail read
I notice that the sensor update data to my HomeAssistance server every 5 minutes, can i change that value?
Thanks
Owner
You can change the period report interval on the “Expert” tab.