roomstats

Temperature, humidity, altitude, pressure, and CO2 measurement IoT firmware for ESP8266.

Requirements

• A BME280/BMP280 (or compatible) sensor
• An SGP-30 sensor (optional)
• Adafruit Sensor, BME280 and SGP30 libraries
• WiFiManager library

Wiring

ESP D1 -> BME280 SCL ESP D2 -> BME280 SDA ESP 3V3 -> BME280 VIN ESP GND -> BME280 GND

If you have an SGP-30 too: ESP D1 -> SGP30 SCL ESP D2 -> SGP30 SDA ESP 3V3 -> SGP30 VIN (make sure your board has a voltage regulator, since the chip is 1.8V) ESP GND -> SGP30 GND

Usage

On first boot, WifiManager will start. Configure your WiFi settings.

Then, you can reach the board on it's IP logged in serial/set in the static IP settings. Port 80 will get you a JSON with the data acquired by the board:

• temperature: Temperature in celsius
• humidity: Humidity percentage
• pressure: Pressure in hPa
• altitude: Altitude from sea level in meters
• co: CO2 level in ppm (only with SGP-30)
• tvco: indoor total VOC (only with SGP-30)

Note that some sensors may need to be calibrated.

Configuration

IMPORTANT: You may need to change the I2C address of the BME280 specified in bme.begin.

You can configure the following variables in roomstats.ino:

• Static IP address: Change STATIC_IP, STATIC_GATEWAY and STATIC_MASK. Comment them out to enable DHCP.
• I2C address of BME280: Change 0x76 in bme.begin call.

Housing

You can 3D print the Box.stl and Box Lid.stl files to make a housing for the board. The box is designed around the Apple iPhone charger (slim version, EU version, not sure if there's a difference).

You can solder on a USB jack to the ESP's 5V and GND pins, or you can use a really short microUSB cable.