72 lines
2.3 KiB
Arduino
72 lines
2.3 KiB
Arduino
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// Example testing sketch for various DHT humidity/temperature sensors
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// Written by ladyada, public domain
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#include "DHT.h"
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#define DHTPIN 2 // what pin we're connected to
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// Uncomment whatever type you're using!
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//#define DHTTYPE DHT11 // DHT 11
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#define DHTTYPE DHT22 // DHT 22 (AM2302)
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//#define DHTTYPE DHT21 // DHT 21 (AM2301)
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// Connect pin 1 (on the left) of the sensor to +5V
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// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1
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// to 3.3V instead of 5V!
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// Connect pin 2 of the sensor to whatever your DHTPIN is
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// Connect pin 4 (on the right) of the sensor to GROUND
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// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor
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// Initialize DHT sensor for normal 16mhz Arduino
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DHT dht(DHTPIN, DHTTYPE);
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// NOTE: For working with a faster chip, like an Arduino Due or Teensy, you
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// might need to increase the threshold for cycle counts considered a 1 or 0.
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// You can do this by passing a 3rd parameter for this threshold. It's a bit
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// of fiddling to find the right value, but in general the faster the CPU the
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// higher the value. The default for a 16mhz AVR is a value of 6. For an
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// Arduino Due that runs at 84mhz a value of 30 works.
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// Example to initialize DHT sensor for Arduino Due:
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//DHT dht(DHTPIN, DHTTYPE, 30);
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void setup() {
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Serial.begin(9600);
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Serial.println("DHTxx test!");
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dht.begin();
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}
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void loop() {
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// Wait a few seconds between measurements.
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delay(2000);
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// Reading temperature or humidity takes about 250 milliseconds!
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// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
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float h = dht.readHumidity();
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// Read temperature as Celsius
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float t = dht.readTemperature();
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// Read temperature as Fahrenheit
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float f = dht.readTemperature(true);
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// Check if any reads failed and exit early (to try again).
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if (isnan(h) || isnan(t) || isnan(f)) {
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Serial.println("Failed to read from DHT sensor!");
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return;
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}
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// Compute heat index
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// Must send in temp in Fahrenheit!
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float hi = dht.computeHeatIndex(f, h);
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Serial.print("Humidity: ");
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Serial.print(h);
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Serial.print(" %\t");
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Serial.print("Temperature: ");
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Serial.print(t);
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Serial.print(" *C ");
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Serial.print(f);
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Serial.print(" *F\t");
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Serial.print("Heat index: ");
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Serial.print(hi);
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Serial.println(" *F");
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}
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