Prometheus ESP8266 DHT Exporter

An IoT Prometheus exporter for measuring temperature and humidity, using an ESP8266 (Arduino-compatible) with a Wi-Fi module and a DHT (temperature + humidity) sensor.

Metrics

Metric	Description	Unit
dorm_info	Metadata about the device.
dorm_free_heap	Free heap.	byte
dorm_sensor	Metadata about a sensor.
dorm_air_humidity_percent	Air humidity.	%H
dorm_air_temperature_celsius	Air temperature.	°C
dorm_air_heat_index_celsius	Apparent air temperature, based on temperature and humidity.	°C
dorm_air_quality_eco2	Equivalent calculated carbon-dioxide.	ppm
dorm_air_quality_tvoc	Total volatile organic compound.	ppb/t
dorm_air_quality_h2	Hydrogen measurement.	ppm
dorm_air_quality_ethanol	Ethanol measurement.	ppm

Requirements

Hardware

• ESP8266-based board (or some other appropriate Arduino-based board).
  • Tested with "Adafruit Feather HUZZAH ESP8266" and "WEMOS D1 Mini".
• DHT sensor.
  • Tested with a cheap DHT11 from eBay (using pin 12).
  • DHT11 supports a maximum of 1Hz polling while DHT22 supports a maximum of 2Hz polling.
  • Both DHT11 and DHT22 support both 3V and 5V at 2.5mA max current.
• Adafruit SGP30 Sensor

Software

• PlatformIO

Building

Hardware

Using the "Adafruit Feather HUZZAH ESP8266".

Wire the DHT sensor power to the 3.3V and any GND on the ESP and wire the data output to e.g. pin 14 (aka D5).

Version

See src/version.h.

It's set manually since no build tools (or CI) other than the Arduino IDE is used.

License

GNU General Public License version 3 (GPLv3).