代码如下：
#include <inttypes.h> /* * LED */ unsigned int LED = 13; /* * DHT22配置程序 */ unsigned int DHT_PIN = 7; #define DHT_OK 1 #define DHT_ERR_CHECK 0 #define DHT_ERR_TIMEOUT -1 float humidity; float temperature; unsigned char DHT_read() { // BUFFER TO RECEIVE unsigned char bits[5] = {0,0,0,0,0}; unsigned char cnt = 7; unsigned char idx = 0; unsigned char sum; // REQUEST SAMPLE pinMode(DHT_PIN, OUTPUT); digitalWrite(DHT_PIN, LOW); delay(18); digitalWrite(DHT_PIN, HIGH); delayMicroseconds(40); pinMode(DHT_PIN, INPUT); // ACKNOWLEDGE or TIMEOUT unsigned int count = 10000; while(digitalRead(DHT_PIN) == LOW) if (count-- == 0) return DHT_ERR_TIMEOUT; count = 10000; while(digitalRead(DHT_PIN) == HIGH) if (count-- == 0) return DHT_ERR_TIMEOUT; // READ OUTPUT - 40 BITS => 5 BYTES or TIMEOUT for (int i=0; i<40; i++) { count = 10000; while(digitalRead(DHT_PIN) == LOW) if (count-- == 0) return DHT_ERR_TIMEOUT; unsigned long t = micros(); count = 10000; while(digitalRead(DHT_PIN) == HIGH) if (count-- == 0) return DHT_ERR_TIMEOUT; if ((micros() - t) > 40) bits[idx] |= (1 << cnt); if (cnt == 0) // next byte? { cnt = 7; // restart at MSB idx++; // next byte! } else cnt--; } sum = bits[0]+bits[1]+bits[2]+bits[3]; if(bits[4] != sum) return DHT_ERR_CHECK; humidity = (float)((bits[0] << 8)+bits[1])/10; temperature = (float)((bits[2] << 8)+bits[3])/10; return DHT_OK; } void setup() { pinMode(13,OUTPUT);//指示灯 pinMode(DHT_PIN,INPUT); digitalWrite(DHT_PIN, HIGH); } void loop() { DHT_read(); Serial.print("temperature:"); Serial.println(temperature); Serial.println("============end==============="); delay(1000); digitalWrite(LED,HIGH); delay(925); //Delay digitalWrite(LED,LOW); delay(925); //Delay }
DHT22数据手册：http://www.waveshare.net/w/upload/b/be/AM2302_V1.1.pdf