Arduino.ru

Пришел вот такой сенсор MQ-7, на плате 4 вывода:питание, выход аналоговый и цифровой.

вот вырезка характеристик датчика:

Electronic Brick - CO (Carbonic Oxide) Sensor (MQ7) can be used to detect Carbon Monoxide, Coal Gas, Liquefied Gas and so on.

Features

• Working Voltage: 5V
• Heating consumption: 0.5 ~ 800 mW
• Operating Temperature: -25 ~ +85 degree centigrade
• Analog output and digital output
• Fast response time
• Adjustable load resistance
• With Makerduino Demo Code
• With Signal Light
• Weight: 6g

Applications

• CO detector

Вот скетч:

/* MQ-7 Carbon Monoxide Sensor Circuit with Arduino */

const int AOUTpin=0;//the AOUT pin of the CO sensor goes into analog pin A0 of the arduino
const int DOUTpin=8;//the DOUT pin of the CO sensor goes into digital pin D8 of the arduino
const int ledPin=13;//the anode of the LED connects to digital pin D13 of the arduino

int limit;
int value;

void setup() {
Serial.begin(115200);//sets the baud rate
pinMode(DOUTpin, INPUT);//sets the pin as an input to the arduino
pinMode(ledPin, OUTPUT);//sets the pin as an output of the arduino
}

void loop()
{
value= analogRead(AOUTpin);//reads the analaog value from the CO sensor's AOUT pin
limit= digitalRead(DOUTpin);//reads the digital value from the CO sensor's DOUT pin
Serial.print("CO value: ");
Serial.println(value);//prints the CO value
Serial.print("Limit: ");
Serial.print(limit);//prints the limit reached as either LOW or HIGH (above or underneath)
delay(100);
if (limit == HIGH){
digitalWrite(ledPin, HIGH);//if limit has been reached, LED turns on as status indicator
}
else{
digitalWrite(ledPin, LOW);//if threshold not reached, LED remains off
}
}