Created DHT11 sensor library

README.md

@@ -1,2 +1,35 @@
 # DHT11
-DHT11 Arduino Library: A simple and efficient library for reading temperature and humidity data from the DHT11 sensor without dependencies.
+
+This is an Arduino library for the DHT11 temperature and humidity sensor. The library provides an easy-to-use interface for reading temperature and humidity data from the DHT11 sensor.
+
+## How It Works
+
+The DHT11 sensor provides temperature and humidity data over a single-wire interface. This library handles the low-level communication protocol with the sensor, allowing you to read the temperature and humidity data with simple function calls.
+
+When you create an instance of the DHT11 class, you specify the pin that the sensor is connected to. Then, you can call the `readTemperature()` and `readHumidity()` methods to read the temperature and humidity data, respectively. These methods return the temperature in degrees Celsius and the relative humidity in percent, or `-1` if there was an error reading the data.
+
+## Features
+
+- **Easy to use**: Just create an instance of the DHT11 class and call the `readTemperature()` and `readHumidity()` methods.
+- **No dependencies**: This library does not depend on any other libraries, so it's easy to install and use.
+- **Examples included**: The library comes with example sketches that show you how to use it.
+
+## Installation
+
+To install the library, download the latest release from this repository and install it using the Arduino IDE's Library Manager.
+
+## Usage
+
+To use the library, include the `DHT11.h` header file in your sketch, create an instance of the DHT11 class, and call the `readTemperature()` and `readHumidity()` methods. See the example sketches included in the `examples` directory for more details.
+
+## Contributing
+
+Contributions to this library are welcome. Please open an issue if you find a bug or have a feature request, and feel free to submit pull requests if you've implemented a new feature or bug fix.
+
+## License
+
+This library is licensed under the MIT License. Please see the `LICENSE` file for more details.
+
+## External References
+
+- [DHT11 Datasheet](https://www.mouser.com/datasheet/2/758/DHT11-Technical-Data-Sheet-Translated-Version-1143054.pdf)

examples/ReadHumidity/ReadHumidity.ino

@@ -0,0 +1,32 @@
+#include <DHT11.h>
+
+// Create an instance of the DHT11 class and set the digital I/O pin.
+DHT11 dht11(2);
+
+void setup()
+{
+    // Initialize serial communication at 115200 baud.
+    Serial.begin(115200);
+}
+
+void loop()
+{
+    // Read the humidity from the sensor.
+    float humidity = dht11.readHumidity();
+
+    // If the humidity reading was successful, print it to the serial monitor.
+    if (humidity != -1)
+    {
+        Serial.print("Humidity: ");
+        Serial.print(humidity);
+        Serial.println(" %");
+    }
+    else
+    {
+        // If the humidity reading failed, print an error message.
+        Serial.println("Error reading humidity");
+    }
+
+    // Wait for 2 seconds before the next reading.
+    delay(2000);
+}

examples/ReadTempAndHumidity/ReadTempAndHumidity.ino

@@ -0,0 +1,39 @@
+#include <DHT11.h>
+
+// Create an instance of the DHT11 class and set the digital I/O pin.
+DHT11 dht11(2);
+
+void setup()
+{
+    // Initialize serial communication at 115200 baud.
+    Serial.begin(115200);
+}
+
+void loop()
+{
+    // Read the humidity from the sensor.
+    float humidity = dht11.readHumidity();
+
+    // Read the temperature from the sensor.
+    float temperature = dht11.readTemperature();
+
+    // If the temperature and humidity readings were successful, print them to the serial monitor.
+    if (temperature != -1 && humidity != -1)
+    {
+        Serial.print("Temperature: ");
+        Serial.print(temperature);
+        Serial.println(" C");
+
+        Serial.print("Humidity: ");
+        Serial.print(humidity);
+        Serial.println(" %");
+    }
+    else
+    {
+        // If the temperature or humidity reading failed, print an error message.
+        Serial.println("Error reading data");
+    }
+
+    // Wait for 2 seconds before the next reading.
+    delay(2000);
+}

examples/ReadTemperature/ReadTemperature.ino

@@ -0,0 +1,32 @@
+#include <DHT11.h>
+
+// Create an instance of the DHT11 class and set the digital I/O pin.
+DHT11 dht11(2);
+
+void setup()
+{
+    // Initialize serial communication at 115200 baud.
+    Serial.begin(115200);
+}
+
+void loop()
+{
+    // Read the temperature from the sensor.
+    float temperature = dht11.readTemperature();
+
+    // If the temperature reading was successful, print it to the serial monitor.
+    if (temperature != -1)
+    {
+        Serial.print("Temperature: ");
+        Serial.print(temperature);
+        Serial.println(" C");
+    }
+    else
+    {
+        // If the temperature reading failed, print an error message.
+        Serial.println("Error reading temperature");
+    }
+
+    // Wait for 2 seconds before the next reading.
+    delay(2000);
+}

library.properties

@@ -0,0 +1,9 @@
+name=DHT11
+version=1.0.0
+author=Dhruba Saha <dhrubasaha@outlook.com>
+maintainer=Dhruba Saha <dhrubasaha@outlook.com>
+sentence=A library for the DHT11 temperature and humidity sensor.
+paragraph=This library provides an easy-to-use interface for reading temperature and humidity data from a DHT11 sensor. It does not depend on any other libraries.
+category=Sensors
+url=http://github.com/dhrubasaha08/DHT11
+architectures=*

src/DHT11.cpp

@@ -0,0 +1,96 @@
+#include "DHT11.h"
+
+// Initializes the pin and sets it to output mode.
+DHT11::DHT11(int pin)
+{
+  _pin = pin;
+  pinMode(_pin, OUTPUT);
+  digitalWrite(_pin, HIGH);
+}
+
+// Reads and returns the temperature from the sensor. Returns -1 if the checksum is incorrect.
+float DHT11::readTemperature()
+{
+  delay(150);
+  byte data[5] = {0, 0, 0, 0, 0};
+  startSignal();
+
+  if (digitalRead(_pin) == LOW)
+  {
+    delayMicroseconds(80);
+    if (digitalRead(_pin) == HIGH)
+    {
+      delayMicroseconds(80);
+
+      for (int i = 0; i < 5; i++)
+      {
+        data[i] = readByte();
+      }
+
+      if (data[4] == ((data[0] + data[1] + data[2] + data[3]) & 0xFF))
+      {
+        return data[2];
+      }
+    }
+  }
+  return -1;
+}
+
+// Reads and returns the humidity from the sensor. Returns -1 if the checksum is incorrect.
+float DHT11::readHumidity()
+{
+  delay(150);
+  byte data[5] = {0, 0, 0, 0, 0};
+  startSignal();
+
+  if (digitalRead(_pin) == LOW)
+  {
+    delayMicroseconds(80);
+    if (digitalRead(_pin) == HIGH)
+    {
+      delayMicroseconds(80);
+
+      for (int i = 0; i < 5; i++)
+      {
+        data[i] = readByte();
+      }
+
+      if (data[4] == ((data[0] + data[1] + data[2] + data[3]) & 0xFF))
+      {
+        return data[0];
+      }
+    }
+  }
+  return -1;
+}
+
+// Reads a byte of data from the sensor.
+byte DHT11::readByte()
+{
+  byte value = 0;
+
+  for (int i = 0; i < 8; i++)
+  {
+    while (digitalRead(_pin) == LOW)
+      ;
+    delayMicroseconds(30);
+    if (digitalRead(_pin) == HIGH)
+    {
+      value |= (1 << (7 - i));
+    }
+    while (digitalRead(_pin) == HIGH)
+      ;
+  }
+  return value;
+}
+
+// Sends the start signal to the sensor.
+void DHT11::startSignal()
+{
+  pinMode(_pin, OUTPUT);
+  digitalWrite(_pin, LOW);
+  delay(18);
+  digitalWrite(_pin, HIGH);
+  delayMicroseconds(40);
+  pinMode(_pin, INPUT);
+}

src/DHT11.h

@@ -0,0 +1,29 @@
+#ifndef DHT11_h
+#define DHT11_h
+
+#include "Arduino.h"
+
+// DHT11 class for reading temperature and humidity data from a DHT11 sensor.
+class DHT11
+{
+public:
+  // Takes the pin number as an argument.
+  DHT11(int pin);
+
+  // Reads and returns the humidity from the sensor. Returns -1 if the checksum is incorrect.
+  float readHumidity();
+
+  // Reads and returns the temperature from the sensor. Returns -1 if the checksum is incorrect.
+  float readTemperature();
+
+private:
+  int _pin;
+
+  // Reads a byte of data from the sensor.
+  byte readByte();
+
+  // Sends the start signal to the sensor.
+  void startSignal();
+};
+
+#endif