MS1100 Formaldehyde Benzene Concentration Gas Sensor Module and Arduino example

The sensor is mainly used for the detection of formaldehyde, toluene, benzene and other VOC gas. The sensor is a type of semiconductor products, widely used in equipment, ventilation equipment, ventilation fan, air filter, hood, hood etc..With high sensitivity and stability, it can detect more than 0.1ppm of the gas. It is suitable for the detection of formaldehyde, benzene, xylene and other volatile organic compounds in the air,small size, cheap, widely used in a variety of small appliances.

The sensor has two pins A0 and D0.
The A0 pin represents the detection of other content. The larger the amount of content detected, the larger the A0 analog value is. Unfortunately this can ve various VOC's, you cannot detect individual ones.
The D0 pin represents whether the gas content exceeds the zero threshold. When it exceeds the threshold then D0 outputs a HIGH level; when it does not exceed the threshold value then D0 outputs LOW. You are able to adjust the zero threshold value by the potentiometer on the back.
The sensor has an LED to indicate whether the gas content exceeds the set zero limit.

Specs

Operating voltage: DC 5V
Operating current: 100mA
Maximum power: 1W
Operating temperature range: -25°C to 65°C

heating voltage: 5V + 2% (AC . DC)
Working current: 100mA (max)
circuit voltage: < DC12V
load resistance: 1K (adjustable)
detection concentration range :0-1000ppm (different gases different scope)
clean air voltage: < 1V
Sensitivity: > 3%
response time: < 5S (preheat 3-5 minutes)
response time:> 10S
component power consumption: �430mW
Working temperature: -10 ~ 60 oC (nominal temperature 20 oC)
Humidity: 90% RH (nominal humidity 65% RH)
lifespan : 5 years

Application:

For the home environment and other air fresheners detection. smoke control ventilation fans and other equipment suitable for testing the concentration range: 0 to 1000ppm qualitative detection of the gas

Parts

I used a sensor shield and connected the sensor to this – the sensor costs about $7.23

Connection

Code

Fairly simple, no libraries just checking the values of D2 and A0 – you can use other pins you would have to change the code

#define Aout A0
#define Dout 2

void setup() 
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(Aout,INPUT);
  pinMode(Dout,INPUT);
}

void loop() 
{
  // put your main code here, to run repeatedly:
  int a=analogRead(Aout);
  int b=digitalRead(Dout);
  Serial.print("D0:");
  Serial.print(b);
  Serial.print("   A0:");
  Serial.println(a);
  delay(500);
}

Output

Open the serial monitor. The greater the measured gas concentration, the greater the A0 value is.
When the detected gas exceeds the set zero limit, D0 is 1, the D1 LED on the sensor lights up; otherwise D0 is 0, and the D1 LED on the sensor is off.

This is what I saw

D0:0 A0:770
D0:0 A0:757
D0:0 A0:755
D0:0 A0:764
D0:0 A0:767
D0:0 A0:760
D0:0 A0:765
D0:0 A0:769