Hacking

The CO2-Ampel is a device that can easily be "hacked". This means that you can add your own extensions, create modifications or run your own code on it. The device is also very easy to repair if one part is broken.

Basic facts:

• Circuit board is designed for SCD30 and MH-Z19B sensors. SCD30 is the default sensor

• Communication to the Sensirion SCD30 happens over i2c. Its address is 0x61.

• SDA: GPIO4/D2, SCL: GPIO5/D1

• The LDR is connected to the analog pin AO/ADC

• The WS2812B strips (12 LEDS) are connected to pin GPIO15/D8. Numbering of the LEDs , see below (front view).

  0 o    o 11
  1 o    o 10
  2 o    o 9
  3 o    o 8
  4 o    o 7
  5 o    o 6
  

• The button is connected to GPIO0/D3

• Resistor:

  • R1: 470 Ohm
  • R3: 10 kOhm
  • R4: 0 Ohm (Bridge for the SCD30, needed for a MH-Z19B)

Additional sensors

Remove the lower back cover to get access to the unpopulated header for the i2c bus.

Using pins of the ESP8266 development board requires more skills as you have to solder the connection. Also, the CO2-Ampel has to be dissembled completely. The GPIOs of the ESP8266 development board would allow you to extend the device even more.

Modifications

If you have a cool modification, please let us know. We would be happy to list it here.