登陆可实现PC、移动端同步进度.
在本节中,我们将学习如何使用不同的传感器连接我们的Arduino板。我们将讨论以下传感器:
- 湿度传感器(DHT22)
- 温度传感器(LM35)
- 水位检测传感器(简单水触发器)
- PIR传感器
- 超声波传感器
- GPS
湿度传感器(DHT22)
DHT-22(也称为AM2302)是一个数字输出,相对湿度和温度传感器。它使用电容式湿度传感器和热敏电阻来测量周围空气,并在数据引脚上发送数字信号。
在本例中,你将学习如何将此传感器与Arduino UNO一起使用。室温和湿度将打印到串口监视器上。
DHT-22传感器
连接很简单。左边的第一个引脚为3-5V电源,第二个引脚连接到数据输入引脚,最右边的引脚接地。
技术细节
-
电源 - 3-5V
-
最大电流 - 2.5mA
-
湿度 - 0-100%,精确度为2-5%
-
温度 - 40至80°C,精确度为±0.5°C
必需的组件
你将需要以下组件:
- 1 × Breadboard 面包板
- 1 × Arduino Uno R3
- 1 × DHT22
- 1 × 10K欧姆电阻
程序
按照电路图连接面包板上的组件,如下图所示。
草图
在计算机上打开Arduino IDE软件。使用Arduino语言进行编码控制你的电路。通过单击“New”打开一个新的草图文件。
Arduino代码
// Example testing sketch for various DHT humidity/temperature sensors #include "DHT.h" #define DHTPIN 2 // what digital pin we're connected to // Uncomment whatever type you're using! //#define DHTTYPE DHT11 // DHT 11 #define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321 //#define DHTTYPE DHT21 // DHT 21 (AM2301) // 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. // Note that older versions of this library took an optional third parameter to // tweak the timings for faster processors. This parameter is no longer needed // as the current DHT reading algorithm adjusts itself to work on faster procs. DHT dht(DHTPIN, DHTTYPE); void setup() { Serial.begin(9600); Serial.println("DHTxx test!"); dht.begin(); } void loop() { delay(2000); // Wait a few seconds between measurements float h = dht.readHumidity(); // Reading temperature or humidity takes about 250 milliseconds! float t = dht.readTemperature(); // Read temperature as Celsius (the default) float f = dht.readTemperature(true); // Read temperature as Fahrenheit (isFahrenheit = true) // Check if any reads failed and exit early (to try again). if (isnan(h) || isnan(t) || isnan(f)) { Serial.println("Failed to read from DHT sensor!"); return; } // Compute heat index in Fahrenheit (the default) float hif = dht.computeHeatIndex(f, h); // Compute heat index in Celsius (isFahreheit = false) float hic = dht.computeHeatIndex(t, h, false); Serial.print ("Humidity: "); Serial.print (h); Serial.print (" %\t"); Serial.print ("Temperature: "); Serial.print (t); Serial.print (" *C "); Serial.print (f); Serial.print (" *F\t"); Serial.print ("Heat index: "); Serial.print (hic); Serial.print (" *C "); Serial.print (hif); Serial.println (" *F"); }
代码说明
DHT22传感器具有四个端子连接到电路板的端子(Vcc,DATA,NC,GND),如下:
- DATA引脚连接到Arduino的2号引脚号
- Vcc引脚连接到Arduino板的5伏电压
- GND引脚连接到Arduino板的接地
- 我们需要在DATA和Vcc引脚之间连接10k欧姆电阻(上拉电阻)
一旦硬件连接完成,你需要添加DHT22库到你的Arduino库文件,如前所述。
结果
你将看到串口监视器上的温度和湿度显示,每2秒更新一次。
- 还没有人评论,欢迎说说您的想法!