MQ135 - Air sensitive quality sensor that detects NH3, NOx, alcohol, benzene, smoke, CO2, etc.
Heater voltage 5V, 31 ohm (40mA consumption)
The board has digital and analog output.
FEATURES
Detects NH3, NOx, alcohol, benzene, smoke, CO2, etc.
Operating voltage 5V
Operating current 40mA
Both digital and analog output
Popular sensor - a lot of examples available for different platforms
Port explanation : AO for analog output, DO for digital output, GND for ground, VCC for 5V voltage input