MQ-135 Air Quality Sensor Hazardous Harmful Gas Detection เซ็นเซอร์ตรวจับแก๊สที่เป็นอัตรายแก่มนุษย์

Features:

Using high-quality dual-panel design,with power indicator and TTL signal output instructions.    

The switching signal having a DO (TTL) output and analog output AO.    

TTL output valid signal is low. ( Low-level signal when the output light can be directly connected to the microcontroller or relay module )    

Analog output voltage with the higher concentration of higher voltage    

There are four screw holes for easy positioning.    

Has a long life and reliable stability    

Rapid response and recovery characteristic   

 

Electrical properties:

Input voltage : DC5V Power consumption ( current ): 150mA

DO output : TTL digital 0 and 1 ( 0.1 and 5V)

AO output :0.1-0 .3 V ( relative to pollution ),the maximum concentration of a voltage of about 4V

Special note: After the sensor is powered,needs to warm up around 20S,measured data was stable,heat sensor is a normal phenomenon,because the internal heating wire,if hot is not normal .  

 

Wiring:

VCC: positive power supply (5V)    

GND: power supply is negative    

DO: TTL switching signal output    

AO: analog signal output

 

Instructable : https://www.instructables.com/id/Air-Quality-Check-With-Arduino-Uno/

Arduino Project HUB : https://create.arduino.cc/projecthub/m_karim02/arduino-and-mq-135-gas-sensor-with-arduino-code-a8c1c6