MQ-135 air quality sensor for Arduino, NodeMCU
The MQ135 sensor monitors the room air. According to the manufacturer's data sheet for CO2, alcohol, benzene, NOx, NH3.
- This sensor is ready for connection to microcontrollers such as a NodeMCU.
- The module has a potentiometer to set the threshold value. The sensor only outputs a 0 or 1 on the digital pin, depending on whether the set threshold value is exceeded.
- The sensor gets warm during operation.
- The sensor has a burn-in phase ". The values stabilize after approx. 48 hours.
- The sensor has a warm-up phase of approx. 30 seconds until it delivers correct values.
Assignment of the pins
- VCC: power supply 5V
- GND: ground connection
- AOUT: Analog output
- DOUT: digital output