Fixed voltage calculation

examples/MQ-Board-Calibration/MQ-Board-Calibration.ino

@@ -133,7 +133,7 @@ void loop() {
   Serial.print(lecture6);Serial.print(",");
   Serial.print(lecture7);Serial.print(",");
   Serial.print(lecture8);Serial.print(",");
-  Serial.println(lecture9);Serial.print(",");
+  Serial.print(lecture9);Serial.print(",");
   //Print voltages
   Serial.print(v2);Serial.print(",");
   Serial.print(v3);Serial.print(",");
@@ -142,7 +142,7 @@ void loop() {
   Serial.print(v6);Serial.print(",");
   Serial.print(v7);Serial.print(",");
   Serial.print(v8);Serial.print(",");
-  Serial.println(v9);Serial.print(",");
+  Serial.println(v9);
   
 
   //Print in LCD

src/MQUnifiedsensor.cpp

@@ -565,10 +565,10 @@ double MQUnifiedsensor::getVoltage(int read) {
   {
     double avg = 0.0;
     for (int i = 0; i < retries; i ++) {
-      avg += analogRead(this->_pin) / retries;
+      avg += analogRead(this->_pin);
       delay(retry_interval);
     }
-    voltage = avg * _VOLT_RESOLUTION / (pow(2, ADC_RESOLUTION) - 1);
+    voltage = (avg/ retries) * _VOLT_RESOLUTION / (pow(2, ADC_RESOLUTION) - 1);
   }
   return voltage;
 }