In the last issue, the blogger analyzed the Zigbee protocol of Xiaomi's temperature and humidity sensor, see the blog post: Xiaomi Temperature and Humidity Sensor Protocol Analysis
After the blog post, the blogger said that he wanted to capture the packets on Xiaomi's own gateway. This paper will publish the results of the study.
The blogger borrowed a green rice gateway, and according to its instructions, entered the temperature and humidity into the network, and used the packet grabber to enter the network process:
It can be seen from the above process that the temperature and humidity access to the network is the same as the process of entering our own gateway. Lumi Gateway did not return anything.
So, no special treatment is done.
Since no processing is done, how does the temperature and humidity behave in Xiaomi's own gateway?
The blogger opened the packet grabber overnight, and the results are as follows:
It is also the same, sometimes there are numbers, sometimes no data is reported. There is no real data from 1:00 to 6:30.
Looking at Xiaomi's App, there is no more intuitive data displayed on it (sorry, I forgot to take a screenshot). However, the small ripples displayed may be fabricated data.
Perhaps, the temperature value is a device, and it is reported only when it changes (there is this property configuration item in the Zigbee protocol). Then the blogger pours a cup of hot water to test. result:
This confirms my speculation.
Long-term observation, the display effect in Zhijia 365:
Intermittent reporting of temperature values results in mostly dashed lines in the graph.
The conclusion is:
- Xiaomi's temperature and humidity sensor will only report attributes when there is a large jump in the temperature and humidity values, but not usually.
- There will be 1 private property report per hour as a heartbeat.
- It has no power management (at least I didn't see any data packets related to power, nor did I find a related power display in its official App)