Xiaomi Mijia bluetooth temperature/humidity sensor

This is an application for collecting sensor measurements from Xiaomi Mijia bluetooth temperature/humidity sensor. It’s based on reading output of hcidump tool and passive scanning of BLE devices with hcitool tool. The description of a protocol used by the sensor is described at the following link: https://github.com/mspider65/Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor/blob/master/SensorProtocol.html

Dependencies

• openjdk-11-jdk

• bluez

• bluez-hcidump

Build

./gradlew clean build

Usage

1. Start scanning for BLE devices in passive mode

   hciconfig hci0 up
   hcitool lescan --passive --duplicates

   Tip	The hcitool lescan command may fail with various errors, for example: Set scan parameters failed: Input/output error You may try to fix it with hciconfig hci0 reset or rfkill unblock bluetooth.

2. Start the collector specifying MAC address(es) of sensors to monitor

   hcidump -R | ./xiaomi-mijia-bluetooth-sensor 582D3430247C 362D34303089 ...

   The following is example output:

   {"time":"2020-05-21T06:51:24.450Z","humidity":34.3,"temperature":22.1,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:26.447Z","temperature":22.1,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:28.454Z","humidity":34.2,"temperature":22.1,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:34.465Z","humidity":34.1,"temperature":22.0,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:36.465Z","humidity":34.0,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:38.467Z","batteryLevel":31.0,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:40.475Z","humidity":34.2,"temperature":22.0,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:42.483Z","humidity":34.1,"temperature":22.0,"mac":"582D3430247C"}
   {"time":"2020-05-21T06:51:44.481Z","humidity":34.1,"temperature":22.1,"mac":"582D3430247C"}

Sensor data visualisation with Grafana

1. Start collecting data from a sensor dumping measurements into file

   hcidump -R | ./xiaomi-mijia-bluetooth-sensor 582D3430247C 362D34303089 ... | tee -a /tmp/metrics.json

2. Start several docker containers with docker-compose that will run instances of: Telegraf, InfluxDB and Grafana.

   SENSOR_METRICS_FILE_PATH=/tmp/metrics.json docker-compose up

   Note	SENSOR_METRICS_FILE_PATH should point to the file where metrics from the application are dumped. This is the file which will be tailed by Telegrag.

3. In Grafana, add a datasource of type InfluxDB pointing to database created by telegraf

4. Import the dashboard: grafana-dashbpard.json or just use Explore to monitor temperature measurements:

   Data Source: InfluxDB
   From: defaul xiaomi-mijia-bluetooth-sensor
   Select: field(temperature) mean()
   Group By: time($_interval) fill(null)
   Format as: Time series.

5. Leave things working for several hours

6. After several hours you should observe graph(s) full of data

   

Misc. references

• https://manned.org/hcidump/bdb92bdc

• https://gitlab.com/jtaimisto/bluewalker

• sidddy/flora#8

• https://www.silabs.com/community/wireless/bluetooth/knowledge-base.entry.html/2017/02/10/bluetooth_advertisin-hGsf