   float t = dht.readTemperature();
 
   {
-    Serial.print(millis()/1000);
+    Serial.print(millis()/1000);  // elapsed seconds since boot
     Serial.print(",");
     Serial.print(h,1);
     Serial.print(",");

float concentration = 0;
int sensorValue = 0;

#define DHTPIN A2
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

void setup() {

  0x07, 0x03, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
int pin = 8;  //inititalizing digital pin 8, dust sensor
unsigned long duration;
unsigned long starttime;
unsigned long sampletime_ms = 5000;
