Matrix - Temperature and Humidity Sensor
From FriendlyELEC WiKi
Contents
1 介绍
此配件搭载DHT11温湿度传感器。DHT11是一款入门级传感器,湿度采集范围为20%-80%,误差为5%,温度采集范围为0℃-50℃,误差为±2℃,适合要求不高的场合使用。我们把DHT11的4针引脚简化为3针引出,并在PCB上加上固定孔,方便您安装使用。
2 特性
- 测量范围 湿度20-90%RH, 温度0~50℃
- 测量精度 湿度+-5%RH, 温度+-2℃
- 一线协议
- 2.54mm排针接口,接线方便,通用性强
3 使用方法
3.1 连接
- 连接到Tiny4412 SDK (1506)
- GND针脚: 接地
- VCC: 接5V
- S针脚:接GPIO PIN1, 必须使用中断引脚,可用引脚(1、2、3、4、9、10)
3.2 Linux下的C示例
#include <stdio.h> #include <stdlib.h> #include "libfahw.h" void parseCmd(int argc, char **argv, int *pin) { int num = atoi(argv[1]); switch(num) { case 1: *pin = TINY4412_GPIO_PIN1; break; case 2: *pin = TINY4412_GPIO_PIN2; break; case 3: *pin = TINY4412_GPIO_PIN3; break; case 4: *pin = TINY4412_GPIO_PIN4; break; case 9: *pin = TINY4412_GPIO_PIN9; break; case 10: *pin = TINY4412_GPIO_PIN10; break; default: printf("Unsupported pin TINY4412_GPIO_PIN%d\n", num); num = 1; *pin = TINY4412_GPIO_PIN1; } printf("Using pin TINY4412_GPIO_PIN%d\n", num); } int main(int argc, char ** argv) { int ret = -1; int dhtTemp = 0; int dhtHdty = 0; int devFD = -1; int pin = TINY4412_GPIO_PIN1; if (argc == 2) { parseCmd(argc, argv, &pin); } else { printf("Using default pin TINY4412_GPIO_PIN1\n"); } if ((devFD = dht11Init(pin)) == -1) { printf("Fail to init dht11\n"); return -1; } if ((ret = dht11Read(DHT_HUMIDITY, &dhtHdty)) != -1) { printf("Get humidity : %d\n", dhtHdty); } else { printf("Faided to get humidity\n"); } if ((ret = dht11Read(DHT_TEMP, &dhtTemp)) != -1) { printf("Get temperature : %d\n", dhtTemp); } else { printf("Faided to get temperature\n"); } dht11DeInit(devFD); return ret; }
3.3 编译并运行示例
git clone http://github.com/friendlyarm/fa-hardware.git cd fa-hardware cd demo cd matrix-temperature_and_humidity_sensor make
将编译生成的dht11通过ftp上传到开发板上运行即可测试。