简介：DHT11是一款有已校准数字信号输出的温湿度传感器。 该传感器内部包括一个电阻式感湿元件和一个NTC测温元件。在使用上其精度湿度±5%RH， 温度±2℃，量程湿度5~95%RH， 温度-20~+60℃
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那么今天我们在写一个C语言的实例教程。对于完全0基础的小白按照教程一步步来也能轻松实现！
二：安装 WiringPi
这里使用了 WiringPi 库，（如果已经安装过可以跳过这一步）依次输入下面五条命令进行安装
sudo apt-get update
sudo apt-get install git-core
git clone /WiringPi/WiringPi
cd WiringPi
sudo ./build
四：代码程序
新建dht11.c文件，保存下面代码程序，ctrl+x保存按Y （不会新建的朋友可以输入sudo nano dht11.c来新建文件）
#include <wiringPi.h>#include <stdio.h>#include <stdlib.h>typedef unsigned char uint8;typedef unsigned int uint16;typedef unsigned long uint32;#define HIGH_TIME 32int pinNumber = 7;uint32 databuf;uint8 readSensorData(void){uint8 crc; uint8 i;pinMode(pinNumber, OUTPUT); // set mode to outputdigitalWrite(pinNumber, 0); // output a high level delay(25);digitalWrite(pinNumber, 1); // output a low level pinMode(pinNumber, INPUT); // set mode to inputpullUpDnControl(pinNumber, PUD_UP);delayMicroseconds(27);if (digitalRead(pinNumber) == 0) //SENSOR ANS{while (!digitalRead(pinNumber)); //wait to highfor (i = 0; i < 32; i++){while (digitalRead(pinNumber)); //data clock startwhile (!digitalRead(pinNumber)); //data startdelayMicroseconds(HIGH_TIME);databuf *= 2;if (digitalRead(pinNumber) == 1) //1{databuf++;}}for (i = 0; i < 8; i++){while (digitalRead(pinNumber)); //data clock startwhile (!digitalRead(pinNumber)); //data startdelayMicroseconds(HIGH_TIME);crc *= 2; if (digitalRead(pinNumber) == 1) //1{crc++;}}return 1;}else{return 0;}}int main(void){printf("PIN:%d\n", pinNumber);if (-1 == wiringPiSetup()) {printf("Setup wiringPi failed!");return 1;}pinMode(pinNumber, OUTPUT); // set mode to outputdigitalWrite(pinNumber, 1); // output a high level printf("Starting...\n");while (1) {pinMode(pinNumber, OUTPUT); // set mode to outputdigitalWrite(pinNumber, 1); // output a high level delay(3000);if (readSensorData()){printf("Sensor data read ok!\n");printf("RH:%d.%d\n", (databuf >> 24) & 0xff, (databuf >> 16) & 0xff); printf("TMP:%d.%d\n", (databuf >> 8) & 0xff, databuf & 0xff);databuf = 0;}else{printf("Sensor dosent ans!\n");databuf = 0;}}return 0;}
五：编译程序并运行
gcc -Wall -o dht11 dht11.c -lwiringPi
忽略编译过程中的警告。运行之后将出现温湿度读数。
在执行下面命令可获取温度数据
sudo ./dht11
原文转自/index.php?c=read&id=251&page=1
