Updated examples (Issue 26)

examples/MQ-309A/MQ-309.ino

@@ -31,14 +31,16 @@
 #define type "MQ-309" //MQ309
 #define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO
 #define RatioMQ309CleanAir 11 //RS / R0 = 11 ppm 
-//#define calibration_button 13 //Pin to calibrate your sensor
+#define PWMPin 5 // Pin connected to mosfet
 
 //Declare Sensor
 MQUnifiedsensor MQ309(placa, Voltage_Resolution, ADC_Bit_Resolution, pin, type);
+unsigned long oldTime = 0;
 
 void setup() {
   //Init the serial port communication - to debug the library
   Serial.begin(9600); //Init serial port
+  pinMode(PWMPin, OUTPUT);
 
   //Set math model to calculate the PPM concentration and the value of constants
   MQ309.setRegressionMethod(1); //_PPM =  a*ratio^b
@@ -86,8 +88,28 @@ void setup() {
 }
 
 void loop() {
+  // 60s cycle
+  oldTime = millis();
+  while(millis() - oldTime <= (30*1000))
+  {
+    // VH 0.9 Volts
+    analogWrite(5, 2); // 255 is 100%, 2.295 is aprox 0.9% of Duty cycle for 60s
     MQ309.update(); // Update data, the arduino will be read the voltage on the analog pin
     MQ309.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup
     MQ309.serialDebug(); // Will print the table on the serial port
     delay(500); //Sampling frequency
+  }
+
+  // 90s cycle
+  oldTime = millis();
+  while(millis() - oldTime <= (120*1000))
+  {
+    // VL 0.2 Volts
+    analogWrite(5, 1); // 255 is 100%, 0.51 is aprox 0.2% of Duty cycle for 120s
+    MQ309.update(); // Update data, the arduino will be read the voltage on the analog pin
+    MQ309.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup
+    MQ309.serialDebug(); // Will print the table on the serial port
+    delay(500); //Sampling frequency
+  } 
+  // Total: 30 + 120s =  2.5 minutes.
 }

examples/MQ-7/MQ-7.ino

@@ -13,6 +13,10 @@
   modified 26 March 2020
   by Miguel Califa 
 
+  Updated example of MQ-7 AND MQ-309A
+  modified 20 April 2020
+  by Miguel Califa
+
   Wiring:
   https://github.com/miguel5612/MQSensorsLib_Docs/blob/master/static/img/MQ_Arduino.PNG
   Please take care, arduino A0 pin represent the analog input configured on #define pin
@@ -31,14 +35,16 @@
 #define type "MQ-7" //MQ7
 #define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO
 #define RatioMQ7CleanAir 27.5 //RS / R0 = 27.5 ppm 
-//#define calibration_button 13 //Pin to calibrate your sensor
+#define PWMPin 5 // Pin connected to mosfet
 
 //Declare Sensor
 MQUnifiedsensor MQ7(placa, Voltage_Resolution, ADC_Bit_Resolution, pin, type);
+unsigned long oldTime = 0;
 
 void setup() {
   //Init the serial port communication - to debug the library
   Serial.begin(9600); //Init serial port
+  pinMode(PWMPin, OUTPUT);
 
   //Set math model to calculate the PPM concentration and the value of constants
   MQ7.setRegressionMethod(1); //_PPM =  a*ratio^b
@@ -87,8 +93,28 @@ void setup() {
 }
 
 void loop() {
+  // 60s cycle
+  oldTime = millis();
+  while(millis() - oldTime <= (60*1000))
+  {
+    // VH 5 Volts
+    analogWrite(5, 255); // 255 is DC 5V output
     MQ7.update(); // Update data, the arduino will be read the voltage on the analog pin
     MQ7.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup
     MQ7.serialDebug(); // Will print the table on the serial port
     delay(500); //Sampling frequency
+  }
+
+  // 90s cycle
+  oldTime = millis();
+  while(millis() - oldTime <= (90*1000))
+  {
+    // VH 1.4 Volts
+    analogWrite(5, 20); // 255 is 100%, 20.4 is aprox 8% of Duty cycle for 90s
+    MQ7.update(); // Update data, the arduino will be read the voltage on the analog pin
+    MQ7.readSensor(); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup
+    MQ7.serialDebug(); // Will print the table on the serial port
+    delay(500); //Sampling frequency
+  } 
+  // Total: 60 + 90s =  2.5 minutes.
 }

examples/MQ-Board/MQ-Board.ino

@@ -29,6 +29,7 @@
 #define         Pin7                     (A7)  //Analog input 7 of your arduino
 #define         Pin8                     (A8)  //Analog input 8 of your arduino
 #define         Pin9                     (A9)  //Analog input 9 of your arduino
+#define         PWMPin                   (5)   // Pin connected to mosfet
 /***********************Software Related Macros************************************/
 #define         RatioMQ2CleanAir          (9.83) //RS / R0 = 9.83 ppm 
 #define         RatioMQ3CleanAir          (60) //RS / R0 = 60 ppm 
@@ -52,6 +53,8 @@ MQUnifiedsensor MQ7(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin7, Type);
 MQUnifiedsensor MQ8(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin8, Type);
 MQUnifiedsensor MQ9(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin9, Type);
 
+unsigned long oldTime = 0;
+
 void setup() {
   //Init serial port
   Serial.begin(9600);
@@ -168,6 +171,27 @@ void setup() {
 }
 
 void loop() {
+  oldTime = millis();
+  while(millis() - oldTime <= (60*1000))
+  { 
+    // VH 5 Volts
+    analogWrite(5, 255); // 255 is DC 5V output
+    readAllSensors();
+    delay(500);
+  }
+  // 90s cycle
+  oldTime = millis();
+  while(millis() - oldTime <= (90*1000))
+  {
+    // VH 1.4 Volts
+    analogWrite(5, 20); // 255 is 100%, 20.4 is aprox 8% of Duty cycle for 90s
+    readAllSensors();
+    delay(500);
+  }
+}
+
+void readAllSensors()
+{
   //Update the voltage lectures
   MQ2.update();
   MQ3.update();