DHT22 Setup, with Simple Error Checking

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

#include "DHT.h"

#define DHTPIN 2     // what digital pin we're connected to

#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

void setup() {
	Serial.begin(9600);
	Serial.println("Reading DHT22 data!");
	dht.begin();
	pinMode(12, OUTPUT); // Green
	pinMode(11, OUTPUT); // Red
}

void loop() {
	// Reading temperature or humidity takes about 250 milliseconds!
	// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
	float hum1 = dht.readHumidity();
	// Read temperature as Celsius
	float temp1 = dht.readTemperature();


	// Check if any reads failed and exit early (to try again).
	if (isnan(hum1) || isnan(temp1)) {
		digitalWrite(11, HIGH);
		digitalWrite(12, LOW);
		Serial.println("Error in reading sensor data!");
		while (isnan(hum1) || isnan(temp1)) {
			hum1 = dht.readHumidity();
			temp1 = dht.readTemperature();
		}
	}
	else {
		digitalWrite(11, LOW);
		digitalWrite(12, HIGH);
	}

	// Wait a few seconds between measurements.
	delay(3000);
	float hum2 = dht.readHumidity();
	float temp2 = dht.readTemperature();

	// Compute heat index in Celsius (isFahreheit = false)
	float hic = dht.computeHeatIndex(temp1, hum1, false);
	Serial.print("Humidity: ");
	Serial.print(round)(hum1 + hum2) / 2));
	Serial.print(" % ");
	Serial.print("Temperature: ");
	Serial.print((temp1 + temp2) / 2);
	Serial.print(" *C ");
	Serial.print("Heat index: ");
	Serial.print(round(hic));
	Serial.println(" *C ");
}