Radio weather station in Home Assistant

Context

I bought a weather station broadcasting in 868 MHz and connect it to Home Assistant. The purpose is to improve my crops watering. From the precipation, the vegetable kind and the location, the right amount for the best growth should be computable.

Bresser ClimateScout weather station 7-in-1 (discontinued)
RTL-SDR Blog V4 website

From radio to MQTT

After setting the weather station and connecting the RTL-SDR v4 radio receiver, a specific version of rtl-sdr driver need to be install for v4 git. On ArchLinux, the rtl-sdr-blog-git and rtl_433-git can be use aur. rtl_433 command use rtl-sdr driver and broadcast the sensor data on MQTT, it can be configure with ~/.config/rtl_433/rtl_433.conf file.

gain          0
frequency     868.30M
hop_interval  600
ppm_error     0
sample_rate   250k
protocol      173 # Bresser Weather Center 7-in-1
output        mqtt=mqtt://ADDRESS:PORT,retain=1,devices=CHANNEL

Change ADDRESS (localhost), PORT (1883) and CHANNEL (rtl_433/bresser71).

A user systemd service can be created in ~/.config/systemd/user/rtl_433.service.

[Unit]
Description=rtl_433 for bresser 7 in 1
After=MQTT.service

[Service]
Type=simple
StandardOutput=journal
ExecStart=rtl_433

[Install]
WantedBy=default.target

Change MQTT with the service name of the MQTT broker.

From MQTT to Home Assistant

In this case, Home Assistant MQTT client will not detect the output of rtl_433. Manual configuration is need and can be done in configuration.yaml of Home Assistant. Creating new sensor and binary_sensor in mqtt.

mqtt:
  sensor:

    - name: Bresser71 Temperature
      state_topic: rtl_433/bresser71/temperature_C
      unique_id: bresser71_temperature_C
      value_template: "{{ value | float }}"
      unit_of_measurement: "°C"
      device_class: temperature

    - name: Bresser71 Humidity
      state_topic: rtl_433/bresser71/humidity
      unique_id: bresser71_humidity
      value_template: "{{ value | int }}"
      unit_of_measurement: "%"
      device_class: humidity

    - name: Bresser71 Wind Gust
      state_topic: rtl_433/bresser71/wind_max_m_s
      unique_id: bresser71_wind_max_m_s
      value_template: "{{ value | float }}"
      unit_of_measurement: "m/s"
      icon: mdi:weather-windy

    - name: Bresser71 Wind Speed
      state_topic: rtl_433/bresser71/wind_avg_m_s
      unique_id: bresser71_wind_avg_m_s
      value_template: "{{ value | float }}"
      unit_of_measurement: "m/s"
      icon: mdi:weather-windy

    - name: Bresser71 Wind Direction Unadjusted
      state_topic: rtl_433/bresser71/wind_dir_deg
      unique_id: bresser71_wind_dir_deg_unadj
      value_template: "{{ value | int }}"
      unit_of_measurement: "°"
      icon: mdi:compass-rose

    - name: Bresser71 Rain
      state_topic: rtl_433/bresser71/rain_mm
      unique_id: bresser71_rain_mm
      value_template: "{{ value | float }}"
      unit_of_measurement: "mm"
      icon: mdi:weather-rainy

    - name: Bresser71 Time
      state_topic: rtl_433/bresser71/time
      unique_id: bresser71_time
      icon: mdi:clock-outline

    - name: Bresser71 UV
      state_topic: rtl_433/bresser71/uv
      unique_id: bresser71_uv
      value_template: "{{ value | int }}"
      icon: mdi:white-balance-sunny

    - name: Bresser71 Light
      state_topic: rtl_433/bresser71/light_lux
      unique_id: bresser71_light_lux
      value_template: "{{ value | int }}"
      unit_of_measurement: "lux"
      icon: mdi:lightbulb-outline

  binary_sensor:

    - name: Bresser71 Battery
      state_topic: rtl_433/bresser71/battery_ok
      unique_id: bresser71_battery_ok
      payload_on: "0"
      payload_off: "1"
      device_class: battery