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--- amc2021:code:start [2021/09/02 12:55] – [For Carbon Dioxide detection in air] leen001
+++ amc2021:code:start [2021/09/03 18:48] (current) – removed kshama001
@@ Line 1: / Line 1: @@
-======Arduino Code======
-===== For Carbon Dioxide detection in air =====
-<code>
-/*
- //Explanation:
-  // This code communicates with the MQ135 air quality sensor. The sensor is supposed to preheat for 2 mins before taking readings
-  // Once the code runs, it prints out the concentration of detected gases in ppm on a serial monitor and a LCD 20 x 4 screen
-  //An alarm system (LED light) is also set to print out messages saying if the air is of a good quality relying on a predefined threshold value
-*/
-  // digital output value is converted to ppm value using CO2 gas as parameter
-#include "MQ135.h"
-#include <Wire.h>
-#include <LiquidCrystal_I2C.h>  //Header file for LCD
-LiquidCrystal_I2C lcd(0x27,16,2);//set the LCD address to x27 for a 16 chars and 2 line display
-#define led          9                       //led on pin 9
-const int gas_pin = A0;                      //analog feed from MQ135
-MQ135 gasSensor = MQ135(gas_pin);
-void setup(){
-  lcd.init();                      // initialize the lcd
-  lcd.begin(16,2);                  // consider 16 chars + 2 lines lcd
-  lcd.backlight();                 // illuminate to produce visible reading
-  lcd.clear();                     // clear lcd
-  lcd.setCursor(4,0);              //set cursor of lcd to 1st row and 5th column
-  lcd.print("Group L");          // print as a sentence on lcd
-  pinMode(gas_pin,INPUT);     //MQ135 analog feed set for input
-  pinMode(led,OUTPUT);        //led set for output
-  Serial.begin(9600);        //serial comms for debugging
-}
-void loop(){
- float ppm = gasSensor.getPPM();
- Serial.println(ppm);            // print ppm on serial monitor
- delay(1000);
-   lcd.clear();                  // clear lcd
-   lcd.setCursor(0,0);          // set cursor of lcd to 1st row and 1st column
-   lcd.print("Air Quality: ");  // print as a sentence on lcd
-   lcd.print(ppm);             // print value of MQ135
- if(ppm>999){                  //if co2 ppm > 1000
-    digitalWrite(led,HIGH);    //turn on led
-    lcd.setCursor(2,1);        // set cursor of lcd to 2nd row and 3rd column
-    lcd.print("AQ Level BAD");  //print as a sentence on lcd
-   }
- else{
-    digitalWrite(led,LOW);         //turn off led
-    lcd.setCursor(1,1);            // set cursor of lcd to 2nd row and 2nd column
-    lcd.print ("AQ Level Good");   // print as a sentence on lcd
-  }
-}
-</code>
-===== **For noise disturbance detection in the environment** =====
-<code>
-/* This code allows to follow the sound intensity using LM393 sensor: The number of times the sensor has detected a sound is summed up over a sampling time
-SAMPLE_TIME. Then the sum (sampleBufferValue) is printed on serial monitor
-A let is used to give a visual alarm if the sampleBufferValue
-surpasses a given Threshold: Threshold*/
-// 0 means silence and 1 means noise
-const int OUT_PIN = 12; // The OUTPUT of the sound sensor is connected to the digital pin D12 of the Arduino
-const int SAMPLE_TIME = 10; // The sampling time
-const int Threshold = 100; // Threshold on cumulative counts for LED switching ON
-unsigned long millisCurrent;
-unsigned long millisLast = 0;
-unsigned long millisElapsed = 0;
-int sampleBufferValue = 0;
-int led = 8; // LED is connected to the digital pin number 4 of the Arduino
-void setup() {
-  // put your setup code here, to run once:
-  Serial.begin(9600);
-  pinMode(led,OUTPUT); // the LED is connected as output
-}
-void loop() { // put your main code here, to run repeatedly:
-  millisCurrent = millis();
-  millisElapsed = millisCurrent - millisLast;
-  if(digitalRead(OUT_PIN) == HIGH){ // HIGH means noise
-  sampleBufferValue++;
-  }
-  if (millisElapsed > SAMPLE_TIME) { //here we will print the counts and test the threshold
-  Serial.println(sampleBufferValue);
-  if (sampleBufferValue > Threshold) {
-    digitalWrite(led, HIGH); //blink LED 2 ms ON and 1 ms OFF
-    delay(2);
-    digitalWrite(led, LOW);
-    delay(1);
-  }
-  digitalWrite(led, LOW);
-  sampleBufferValue = 0;
-  millisLast = millisCurrent;
-  }
-}
-</code>