Added MQ-7 full example in comments

examples/MQ-7/MQ-7.ino

@@ -25,24 +25,31 @@
 
 //Declare Sensor
 
-MQUnifiedsensor MQ7
+MQUnifiedsensor MQ7(pin, type);
-(pin, type);
 
 void setup() {
-  //init the sensor
+   //init the sensor
-  MQ7
+  /*****************************  MQInicializar****************************************
-  .inicializar(); 
+  Input:  pin, type 
+  Output:  
+  Remarks: This function create the sensor object.
+  ************************************************************************************/ 
+  MQ7.inicializar(); 
 }
 
 void loop() {
-  //Read the sensor
+  /*****************************  MQReadSensor  ****************************************
-  int read =  MQ7
+  Input:   Gas - Serial print flag
-  .readSensor();
+  Output:  Value in PPM
-  //Print measurements
+  Remarks: This function use readPPM to read the value in PPM the gas in the air.
-  Serial.print("MQ7
+  ************************************************************************************/ 
-  : ");
+  //Read the sensor and print in serial port
-  Serial.print(read);
+  //Lecture will be saved in lecture variable
-  Serial.println(" PPM");
+  int lecture =  MQ7.readSensor("", true); // Return CH4 concentration
-  //delay 1s to next measure
+  // Options, uncomment where you need
-  delay(1000);
+  //int lecture =  MQ7.readSensor("H2", true); // Return CH4 concentration
+  //int lecture =  MQ7.readSensor("LPG", true); // Return LPG concentration
+  //int lecture =  MQ7.readSensor("CH4", true); // Return CO concentration
+  //int lecture =  MQ7.readSensor("CO", true); // Return Alcohol concentration
+  //int lecture =  MQ7.readSensor("Alcohol", true); // Return smoke concentration
 }