code fixes.

code/sensortest/sensortest.ino

@@ -1,6 +1,6 @@
 #include <math.h>
 
-int DustSensePin = 14;
+int DustSensePin = 13;
 unsigned long duration;
 unsigned long starttime;
 unsigned long sampletime_ms = 30000;//sample 30s ;
@@ -11,6 +11,7 @@ float concentration = 0;
 void setup() 
 {
     Serial.begin(9600);
+    Serial.println("Starting Air Sensor, please wait for readings...");
     pinMode(DustSensePin,INPUT);
     starttime = millis();//get the current time;
 }