Circuit Documentation

Summary

This circuit is designed to collect temperature and humidity measurements using a DHT11 Humidity and Temperature Sensor interfaced with an Arduino UNO microcontroller. The sensor's data pin is connected to the Arduino through a 10k Ohm pull-up resistor, which is a common configuration for digital sensors like the DHT11. The Arduino is programmed to read the sensor data and output the temperature and humidity readings to the serial monitor.

Component List

DHT11 Humidity and Temperature Sensor

• Description: A digital sensor for measuring temperature and humidity.
• Pins: VDD (Power Supply), DATA (Data Output), NULL (No Connection), GND (Ground).

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Pins: Various digital and analog I/O pins, power supply pins, and communication interface pins.

Resistor

• Description: A passive two-terminal electrical component that implements electrical resistance as a circuit element.
• Value: 10,000 Ohms (10k Ohm).

Comment

• Description: A placeholder or annotation within the circuit design, typically containing notes or explanations.

Wiring Details

DHT11 Humidity and Temperature Sensor

• VDD: Connected to the 5V output from the Arduino UNO.
• DATA: Connected to digital pin D2 on the Arduino UNO through a 10k Ohm resistor.
• GND: Connected to the ground (GND) on the Arduino UNO.

Arduino UNO

• 5V: Provides power to the DHT11 sensor.
• D2: Receives the data signal from the DHT11 sensor through a 10k Ohm pull-up resistor.
• GND: Common ground connection for the circuit.

Resistor (10k Ohm)

• One end: Connected to the DATA pin of the DHT11 sensor.
• Other end: Connected to the D2 pin on the Arduino UNO.

Documented Code

/**
 * This example demonstrates how to collect temperature and humidity measurements
 * from the Adafruit DHT11 sensor. Measurements are printed out to the serial monitor.
 *
 * - Make sure to first install the following libraries through the Arduino Library Manager:
 *   - DHT Sensor Library (by Adafruit)
 *   - Adafruit Unified Sensor (by Adafruit)
 * - When you open the serial monitor to view measurements from the DHT11, make sure
 *   that you select 9600 baud so that the serial monitor can receive data from the Arduino.
 *
 * This example was originally written by Adafruit Industries LLC.
 */

#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>

#define DHTPIN 2     // Digital pin connected to the DHT sensor 

// Uncomment the type of sensor in use:
#define DHTTYPE    DHT11     // DHT 11

DHT_Unified dht(DHTPIN, DHTTYPE);

uint32_t delayMS;

void setup() {
  Serial.begin(9600);
  // Initialize device.
  dht.begin();
  Serial.println(F("DHTxx Unified Sensor Example"));
  // Print temperature sensor details.
  sensor_t sensor;
  dht.temperature().getSensor(&sensor);
  Serial.println(F("------------------------------------"));
  Serial.println(F("Temperature Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("°C"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("°C"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("°C"));
  Serial.println(F("------------------------------------"));
  // Print humidity sensor details.
  dht.humidity().getSensor(&sensor);
  Serial.println(F("Humidity Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("%"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("%"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("%"));
  Serial.println(F("------------------------------------"));
  // Set delay between sensor readings based on sensor details.
  delayMS = sensor.min_delay / 1000;
}

void loop() {
  // Delay between measurements.
  delay(delayMS);
  // Get temperature event and print its value.
  sensors_event_t event;
  dht.temperature().getEvent(&event);
  if (isnan(event.temperature)) {
    Serial.println(F("Error reading temperature!"));
  }
  else {
    Serial.print(F("Temperature: "));
    Serial.print(event.temperature);
    Serial.println(F("°C"));
  }
  // Get humidity event and print its value.
  dht.humidity().getEvent(&event);
  if (isnan(event.relative_humidity)) {
    Serial.println(F("Error reading humidity!"));
  }
  else {
    Serial.print(F("Humidity: "));
    Serial.print(event.relative_humidity);
    Serial.println(F("%"));
  }
}

This code is designed to be uploaded to the Arduino UNO microcontroller. It initializes the DHT11 sensor and reads temperature and humidity data, which is then printed to the serial monitor. The code includes detailed comments and instructions for setting up the sensor and libraries required for interfacing with the DHT11.