ESP32 DevKit v1 home sensor connected via I2C to a BME280 sensor which measure temperature, humidity and pressure. Measurements are sent over MQTTv5 to Mosquitto MQTT broker which are then consumed by Telegraf and persisted into InfluxDB.

flowchart LR
    A(fa:fa-microchip ESP32<br /><small><i>outdoor front</i></small>)
    B(fa:fa-microchip ESP32<br /><small><i>indoor living room</i></small>)
    C(fa:fa-microchip ESP32<br /><small><i>indoor bedroom</i></small>)
    D(fa:fa-tower-broadcast Mosquitto MQTT)
    E(fa:fa-gear Telegraf)
    F(fa:fa-database InfluxDB)
    G(fa:fa-chart-line Dashboards)

    A-->D
    B-->D
    C-->D
    D-->E
    E-->F
    F-->G

• espflash
• espmonitor
• espup

Note: I2C devices share the same I2C bus (BME280, SCD30).

Before flashing the device, you will need to configure parameters in the ./cfg.toml file, for example:

[esp32_home_sensor]
wifi_ssid = "my-wifi"
wifi_psk = "wifi-password"
hostname = "esp32-outdoor"
mqtt_hostname = "homie.local"
mqtt_port = 1883
mqtt_username = "esp32-outdoor"
mqtt_password = "someranddompassword"
mqtt_topic = "sensors"
measurement_interval_seconds = 300
location = "outdoor"

Connect the device via USB, then run the following command to run flash and retrieve logs from the device using espmonitor:

espup install

. $HOME/export-esp.sh

cargo run --release

# or run specific features/sensors
cargo run --release --features json,bme280 --no-default-features

Connect the device via USB, then flash it with the following command:

. $HOME/export-esp.sh
cargo espflash flash --release

The following Cargo features allow you to enable/disable sensors and select the MQTT message format to use:

For example, to only enable BME280 with JSON format:

. $HOME/export-esp.sh
# enable BME280, SDS011 with MQTT message in JSON format (default)
cargo espflash flash --release

# enable BME280 with MQTT message in INFLUX format
cargo espflash flash --release --features influx,bme280 --no-default-features

Docker compose is used to setup the infrastructure. It is composed of 4 services:

• InfluxDB - persistent storage and basic dash-boarding
• Mosquitto - MQTT broker
• Telegraf - consume MQTT messages and store them in the database
• A bash job to setup InfluxDB user/token

First, review/adjust environment variables in ./infra/influxdb.env. Then, for each device (one per line) define a username/password in ./infra/mqtt.auth file. For example:

esp32-outdoor:a19sn#sA94k!a5o10
esp32-indoor:a93KifAoBf7#01-jl

After what, run docker compose up -d to deploy the infrastructure.

Note, you might have to restart all containers to get the environment variables re-populated into the container after being generated during initial boot.

You can visualise metrics by importing ./infra/influx-dashboard.json as dashboard into InfluxDB.

It's possible to change the payload format of the MQTT message to JSON instead of Influx by using the --features json.

Refer to the Home Assistant documentation for details on how to set this up.