How I can use multi sensor in one code in Arduino?

Question

How I can use multi smoke sensor in one code? I mean how can I use more than one sensor, where both sensors has the same purpose, like use smoke sensor in multi room. Similar to this code where one is used only. How I can more than one, in Arduino Uno R3,,

<per>
 int redLed = 12;
int greenLed = 11;
int buzzer = 10;
int smokeA0 = A5;
// Your threshold value
int sensorThres = 400;
void setup() {
 pinMode(redLed, OUTPUT);
 pinMode(greenLed, OUTPUT);
pinMode(buzzer, OUTPUT);
pinMode(smokeA0, INPUT);
Serial.begin(9600);
}
void loop() {
 int analogSensor = analogRead(smokeA0);
 Serial.print("Pin A0: ");
 Serial.println(analogSensor);
 // Checks if it has reached the threshold value
 if (analogSensor > sensorThres)
 {
 digitalWrite(redLed, HIGH);
 digitalWrite(greenLed, LOW);
 tone(buzzer, 1000, 200);
 }
 else
 {
 digitalWrite(redLed, LOW);
 digitalWrite(greenLed, HIGH);
 noTone(buzzer);
 }
 delay(100);
}

How I can add more than one sensor to get same purpose. check detect 1 and detect2 and detect 3 if one of this detection LED Red ON, Thanks`

Answer 1

just duplicate the parts of the code that handle the sensor.

int redLed = 12;
int greenLed = 11;
int buzzer = 10;
int smokeSensor1 = A5;
int smokeSensor2 = A4;
int smokeSensor3 = A3;
// Your threshold value
int sensorThres = 400;
void setup() {
 pinMode(redLed, OUTPUT);
 pinMode(greenLed, OUTPUT);
 pinMode(buzzer, OUTPUT);
 pinMode(smokeSensor1, INPUT);
 pinMode(smokeSensor2, INPUT);
 pinMode(smokeSensor3, INPUT);
 Serial.begin(9600);
}
void loop() {
 int analogSensor1 = analogRead(smokeSensor1);
 int analogSensor2 = analogRead(smokeSensor2);
 int analogSensor3 = analogRead(smokeSensor3);
 Serial.print("Pin A0: ");
 Serial.println(analogSensor1);
 // Checks if it has reached the threshold value
 if( (analogSensor1 > sensorThres) || (analogSensor2 > sensorThres) || (analogSensor3 > sensorThres) )
 {
 digitalWrite(redLed, HIGH);
 digitalWrite(greenLed, LOW);
 tone(buzzer, 1000, 200);
 }
 else
 {
 digitalWrite(redLed, LOW);
 digitalWrite(greenLed, HIGH);
 noTone(buzzer);
 }
 delay(100);
}

Answer 2

You haven't mentioned what sensor you are using, so I can't offer any help on how to interface with it. Though you can add 'multi-sensor code' by adding code that will get the state of the sensor at times when you can afford to wait a few ms before checking the state of the other sensors. With the code you provided, you could after the if/else block but before the delay.

Also, it is typically not a good idea to put sensors far away from each other but still connect them to the same controller. You should give each room its own Arduino.

• Moosa Alismaili: I use Mq2 smoke sensor. I mean use mq2 sensor in many room at least 3 sensor in one Arduino uno.