DHT-22 Sensor de Umidade e Temperatura no Arduino

Hoje resolvi iniciar a implementação prática da minha estação Climaduino e Monitora Cerrado através do sensor DHT-22. Segue o esquema de pinagem e esquema de ligação do sensor.

1-Vcc
2-Dados
3-N/C
4-GND

Existem várias maneiras de se capturar os dados, inclusive usando a biblioteca do DHT-22.

http://arduino.cc/playground/Main/DHTLib

1. // Example testing sketch for various DHT humidity/temperature sensors
2. // Written by ladyada, public domain
4. #include "DHT.h"
6. #define DHTPIN 2     // what pin we're connected to
8. // Uncomment whatever type you're using!
9. //#define DHTTYPE DHT11   // DHT 11
10. #define DHTTYPE DHT22   // DHT 22  (AM2302)
11. //#define DHTTYPE DHT21   // DHT 21 (AM2301)
13. // Connect pin 1 (on the left) of the sensor to +5V
14. // Connect pin 2 of the sensor to whatever your DHTPIN is
15. // Connect pin 4 (on the right) of the sensor to GROUND
16. // Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor
18. DHT dht(DHTPIN, DHT22);
20. void setup() {
21.   Serial.begin(9600);
22.   Serial.println("DHTxx test!");
24.   dht.begin();
25. }
27. void loop() {
28.   // Reading temperature or humidity takes about 250 milliseconds!
29.   // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
30.   float h = dht.readHumidity();
31.   float t = dht.readTemperature();
33.   // check if returns are valid, if they are NaN (not a number) then something went wrong!
34.   if (isnan(t) || isnan(h)) {
35.     Serial.println("Failed to read from DHT");
36.   } else {
37.     Serial.print("Humidity: ");
38.     Serial.print(h);
39.     Serial.print(" %\t");
40.     Serial.print("Temperature: ");
41.     Serial.print(t);
42.     Serial.println(" *C");
43.   }
44. }

É importante fazer o download da biblioteca e colocar na pasta librarie do Arduino.
https://github.com/adafruit/DHT-sensor-library

Segunda opção:
https://github.com/ringerc/Arduino-DHT22


http://arduino.cc/playground/Interfacing/Java

http://www.ladyada.net/learn/sensors/dht.html

http://paulo.blog.br/blog/climaduino-projeto-monitoracerrado/