CO₂narienvogel

The project of the Netzbasteln radio-show #148 is a canary bird that measures CO₂ concentration in room air and warns if levels become critical for Covid-19 infection risk. Just like a canary bird warned miners when "Evil Weather" occured.

Threshold values

LED color	CO2 concentration
Green ("all good")	< 1000 ppm
Yellow ("open windows")	1000 – 2000 ppm
Red ("leave room")	> 2000 ppm

Based on coro2sens and ideas from Umwelt-Campus Birkenfeld, which are based on 2008 research by the German Federal Environmental Agency.

Material

1. WEMOS D1 Mini or other ESP8266 board. For ESP32 support check coro2sense
2. Sensirion SCD30 carbon dioxide sensor module.
3. 1 NeoPixel compatible RGB LED (WS2812B).
4. Optional: BME280 I²C pressure sensor module, improves accuracy.
5. 3V piezo buzzer or simple speaker.
6. SG90 5V servo motor.
7. A bird :)

Wiring

ESP pin	goes to
3V3	SCD30 VIN, BME280 VIN
5V	LED +5V, if you dare: Servo (+) (pulls about 70ma)
GND	SCD30 GND, BME280 GND, LED GND, Buzzer (-), Servo (-)
SCL / D1	SCD30 SCL, BME280 SCL
SDA / D2	SCD30 SDA, BME280 SDA
GPIO 0 / D3	LED DIN
GPIO 14 / D5	Buzzer (+)
GPIO 12 / D6	Servo PWM (often brown)

Flash using the Arduino IDE

• Open co2narienvogel.ino in the newest Arduino IDE and make sure you can connect to your device. (Wemos D1 mini clones often use the CH340 driver)
• Install newest ESP8266 support
• And newest libraries (using the built-in library manager, Tools –> Manage Libraries...)
  • Adafruit BME280
  • Adafruit NeoPixel
• Add external libraries (download ZIP from GitHub, then import in Arduino, Sketch -> Include library –> Add .ZIP Library...)
  • paulvha SCD30 library (.zip)
  • ESPAsyncTCP (.zip)
  • ESPAsyncWebServer (.zip)