Graphing Shelly temperatures into Grafana

I own a Shelly i4 (DC model) that keeps an eye on two doors contacts (also knowns as reed switches), which I augmented with a Shelly Plus Addon that keeps an eye on five DS18B20 temperature sensors.

I use Homebridge so I can see the live state of doors and probes through the Homekit app on my phone.

The problem is Homekit won’t provide historical graphs. I’d like to know (for example) if temperature went below 0 degree.

I started looking into this and came up with this approach:

I run everything as Docker containers.


Start an instance:

docker run --name mqtt --restart always -d --net host -v /opt/docker/container/mqtt/mosquitto.conf:/mosquitto/config/mosquitto.conf -v /opt/docker/container/mqtt/data:/mosquitto/data -v /opt/docker/container/mqtt/log:/mosquitto/log eclipse-mosquitto

Bad practice but I allow anonymous connections to MQTT for any external devices. I have a dedicated network segment for devices with no access to the outside. This is the mosquitto.conf file:

listener 1883
allow_anonymous true
persistence true
persistence_location /mosquitto/data/
log_dest file /mosquitto/log/mosquitto.log


Configure your device to send info to MQTT:

Alt text

Alt text

Telegraf + InfluxDB + Grafana

I used this docker-compose.yml file to start all those:

version: "3.8"

    image: influxdb:1.2
    restart: always
    network_mode: "host"
      - /opt/docker/container/mqtt-dashboard/influxdb/:/var/lib/influxdb

    image: telegraf
    restart: always
      - /opt/docker/container/mqtt-dashboard/telegraf/telegraf.conf:/etc/telegraf/telegraf.conf:ro
    network_mode: "host"
      - influxdb

    image: grafana/grafana
    restart: always
    network_mode: "host"
      - /opt/docker/container/mqtt-dashboard/grafana:/var/lib/grafana
      - influxdb


The telegraf.conf makes sure to listen to all MQTT topics and send values to the local InfluxDB instance:

  urls = ["http://localhost:8086"]

  files = ["stdout"]

  servers = ["tcp://localhost:1883"]
  topics = [
  data_format = "json"

I run a fairly old instance of InfluxDB. For some reason I couldn’t get InfluxDB to ingest json_v2 logs for more than a minute. Whoever achieved this, please comment!

Everything runs on the host interface so I point to localhost to reach services.


On first connection to Grafana, you need to reset the password.

Add a data source pointing to InfluxDB:

Alt text

Make sure to point the data source to the telegraf database:

Alt text

Create a new dashboard:

ALl text

An example of query to graph the temperature of my probe:

SELECT last("tC") FROM "mqtt_consumer" WHERE topic = 'shellyi4dc/status/temperature:101' AND $timeFilter GROUP BY time($__interval) fill(previous)


I used mqttui to confirm values were sent by the Shelly to MQTT.

Alt text

Heavily inspired from Handling IOT data with MQTT, Telegraf, InfluxDB and Grafana

Thanks for reading this post!

Did you find an issue in this article?

- click on the following Github link
- log into Github with your account
- click on the line number containing the error
- click on the "..." button
- choose "Reference in new issue"
- add a title and your comment
- click "Submit new issue"

Your feedback is much appreciated! πŸ€œπŸΌπŸ€›πŸΌ

You can also drop me a line below!