DHT11 Temperature and Humidity Sensor

The DHT11 is a digital temperature and humidity sensor that features a calibrated digital signal output. It is low-cost, long-term stable, and capable of measuring relative humidity and temperature. It can collect temperature and humidity data using just a single data line.

Module Source

Purchase Link:
https://item.taobao.com/item.htm?spm=a230r.1.14.23.735720126ougj3&id=522553143872&ns=1&abbucket=12
Baidu Netdisk Download Link: https://pan.baidu.com/s/1HQEL699-Yl5Jh3Hp87_FlQ
Password: 2sgq

Specifications

Operating Voltage: 3-5.5V

Operating Current: 1MA

Measurement Resolution: 8 bit

Communication Protocol: Single bus

Pin Count:3 Pin (2.54mm pitch header)

Hardware Connection

VCC to 5V of the development board

GND to GND of the development board

DATA to a digital pin (e.g., pin 2) on the development board.

The DHT11 typically has a separate data line, and an optional pull-up resistor connected to VCC. Some modules may already include this pull-up resistor.

Usage Method

Install Library

You need to install the library for reading DHT11 data. Adafruit provides a good library that can be installed using the library manager of the Arduino IDE.

• Open the Arduino IDE.
• Go to Tools > Manage Libraries.
• Search DHT sensor library and install it (by Adafruit).

Enter the code:

/******************************************************************************
  * Test Hardware: LCSC ColorEasyDuino Development Board
  * Version Number: V1.0
  * Modified By: www.lckfb.com
  * Modification Date: April 8, 2024
  * Function Overview:
  *****************************************************************************
  * Open-source development board hardware and software information and related projects hardware and software information on official website
  * Development board official website: www.lckfb.com
  * Technical support resident forum, any technical problems are welcome at any time to exchange learning
  * LCSC Forum: club.szlcsc.com
  * Follow our Bilibili account: [立创开发板], stay toned to our latest news!
  * We focus on cultivating Chinese engineers rather than profiting from board sales.
******************************************************************************/
#include "DHT.h"

#define DHTPIN 2     // 定义DHT11数据针脚连接到Arduino的2号引脚
#define DHTTYPE DHT11   // 定义DHT类型为DHT11

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  Serial.println("DHT11 温湿度测试:");

  // 初始化DHT11传感器
  dht.begin();
}

void loop() {
  // 等待几秒钟之间的读取（DHT11 的读取速度相对较慢）
  delay(2000);

  // 读取温度和湿度值
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  // 检查是否读取失败，并退出早期
  if (isnan(h) || isnan(t)) {
    Serial.println("读取DHT11失败！");
    return;
  }

  // 输出读取到的温度和湿度
  Serial.print("湿度: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("温度: ");
  Serial.print(t);
  Serial.println(" °C ");
}

Usage Testing