DHT22(AM2302)示範碼

#include "DHT.h"
#include <ESP8266WiFi.h>

#define DHTPIN 2 // what pin we're connected to
#define DHTTYPE DHT22 // DHT 22 (AM2302)

#define DEBUG

#define DEBUG_PRINTER Serial

#ifdef DEBUG
#define DEBUG_PRINT(...) { DEBUG_PRINTER.print(__VA_ARGS__); }
#define DEBUG_PRINTLN(...) { DEBUG_PRINTER.println(__VA_ARGS__); }
#else
#define DEBUG_PRINT(...) {}
#define DEBUG_PRINTLN(...) {}
#endif

const char* ssid = "OpenWrt_NAT_500GP.101";
const char* password = "activegateway";

DHT *dht;

void connectWifi();
void reconnectWifiIfLinkDown();
void initDht(DHT **dht, uint8_t pin, uint8_t dht_type);
void readDht(DHT *dht, float *temp, float *humid);

void setup() {
Serial.begin(115200);
delay(10);

connectWifi();

initDht(&dht, DHTPIN, DHTTYPE);
}

void loop() {
static float t_ds;
static float t_dht;
static float h_dht;

readDht(dht, &t_dht, &h_dht);
DEBUG_PRINTLN(t_ds);
// Wait a few seconds between measurements.
delay(10 * 1000);

reconnectWifiIfLinkDown();
}

void reconnectWifiIfLinkDown() {
if (WiFi.status() != WL_CONNECTED) {
DEBUG_PRINTLN("WIFI DISCONNECTED");
connectWifi();
}
}

void connectWifi() {
DEBUG_PRINTLN();
DEBUG_PRINTLN();
DEBUG_PRINT("Connecting to ");
DEBUG_PRINTLN(ssid);

WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
DEBUG_PRINT(".");
}

DEBUG_PRINTLN("");
DEBUG_PRINTLN("WiFi connected");
DEBUG_PRINTLN("IP address: ");
DEBUG_PRINTLN(WiFi.localIP());
}

void initDht(DHT **dht, uint8_t pin, uint8_t dht_type) {
// Connect pin 1 (on the left) of the sensor to +5V
// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1
// to 3.3V instead of 5V!
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

// Initialize DHT sensor for normal 16mhz Arduino
// NOTE: For working with a faster chip, like an Arduino Due or Teensy, you
// might need to increase the threshold for cycle counts considered a 1 or 0.
// You can do this by passing a 3rd parameter for this threshold. It's a bit
// of fiddling to find the right value, but in general the faster the CPU the
// higher the value. The default for a 16mhz AVR is a value of 6. For an
// Arduino Due that runs at 84mhz a value of 30 works.
// Example to initialize DHT sensor for Arduino Due:
//DHT dht(DHTPIN, DHTTYPE, 30);

*dht = new DHT(pin, dht_type, 30);
(*dht)->begin();
DEBUG_PRINTLN(F("DHTxx test!")) ;
}

void readDht(DHT *dht, float *temp, float *humid) {

if (dht == NULL) {
DEBUG_PRINTLN(F("[dht22] is not initialised. please call initDht() first."));
return;
}

// Reading temperature or humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
float h = dht->readHumidity();

// Read temperature as Celsius
float t = dht->readTemperature();
// Read temperature as Fahrenheit
float f = dht->readTemperature(true);

// Check if any reads failed and exit early (to try again).
if (isnan(h) || isnan(t) || isnan(f)) {
DEBUG_PRINTLN("Failed to read from DHT sensor!");
return;
}

// Compute heat index
// Must send in temp in Fahrenheit!
float hi = dht->computeHeatIndex(f, h);

DEBUG_PRINT("Humidity: ");
DEBUG_PRINT(h);
DEBUG_PRINT(" %\t");
DEBUG_PRINT("Temperature: ");
DEBUG_PRINT(t);
DEBUG_PRINT(" *C ");
DEBUG_PRINT(f);
DEBUG_PRINT(" *F\t");
DEBUG_PRINT("Heat index: ");
DEBUG_PRINT(hi);
DEBUG_PRINTLN(" *F");

*temp = t;
*humid = f;

}