How to set limit for mq7

How to set limit for mq7 to trigger an alarm i have set the alarm but just need to set the limt to trigger the alarm

:) >:( :( :o :confused:

Well if you've worked out how to read the sensor all you need to do is pick a value above which the alarm triggers.

Post the code you have so far with the sensor being read and the alarm being set.


heres my code

const int AOUTpin=0;//the AOUT pin of the CO sensor goes into analog pin A0 of the arduino const int DOUTpin=7;//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.println( HIGH );//prints the limit reached as either LOW or HIGH (above or underneath) delay(100); if (limit == LOW){ 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 }


how can you do it on the sensor itseelf