Circuit Documentation

Summary

This document provides a detailed overview of a simple circuit that interfaces an Arduino UNO with a DHT11 temperature and humidity sensor. The Arduino UNO serves as the microcontroller for reading data from the DHT11 sensor and transmitting the information via its serial interface. The circuit is powered by the Arduino UNO's 5V output, and the sensor's data pin is connected to one of the digital I/O pins on the Arduino.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Pins Used:
  • IOREF
  • Reset
  • 3.3V
  • 5V
  • GND
  • Vin
  • A0 to A5
  • SCL
  • SDA
  • AREF
  • D13 to D0

DHT11

• Description: A basic, ultra low-cost digital temperature and humidity sensor.
• Pins Used:
  • DATA
  • GND
  • VCC

Wiring Details

Arduino UNO

• 5V connected to DHT11 VCC
• GND connected to DHT11 GND
• D4 connected to DHT11 DATA

DHT11

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• DATA connected to Arduino UNO D4

Documented Code

The following code is written for the Arduino UNO to interface with the DHT11 sensor. It initializes the sensor and reads the temperature and humidity values, which are then printed to the serial monitor.

#include <dht11.h>
#define DHT11PIN 4

dht11 DHT11;

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  Serial.println();

  int chk = DHT11.read(DHT11PIN);

  Serial.print("Humidity (%): ");
  Serial.println((float)DHT11.humidity, 2);

  Serial.print("Temperature (C): ");
  Serial.println((float)DHT11.temperature, 2);

  delay(2000);
}

The code includes the dht11.h library, which provides the necessary functions to communicate with the DHT11 sensor. The DHT11PIN macro is defined as pin 4, which corresponds to the digital I/O pin on the Arduino UNO that the sensor's data line is connected to. The setup() function initializes the serial communication at 9600 baud rate. The loop() function reads the sensor data and prints the humidity and temperature to the serial monitor every 2 seconds.