Arduino-DHTSensor

Arduino library for communicating with the DHT22/AM2302 Digital Temperature And Humidity Sensor without using a pull up resistor. In theory, this should also work for the DHT11 sensor, but I haven't tried it yet.

You can support the author by buying the sensor on ebay.

Setup

Because there is no requirement for a pull up resistor setting up the sensor is very easy and it only requires connecting the sensor to your board via 3 jumper cables.

Remember

• pin1 = VDD
• pin2 = data
• pin3 = not used
• pin4 = GND

Usage

1. Copy the contents of this repository to your arduino libraries directory in a subdirectory named DHTSensor
2. Restart the IDE
3. Profit

#include <DHTSensor.h>
DHTSensor sensor(3);//Will be using pin3 for collecting the data
void loop()
{
		DHTSensorMeasurement re = sensor.Read();
		if (!re.HasError())
		{
			Serial.print("H: ");
			Serial.print(re.Humidity());
			Serial.print(" T: ");
			Serial.print(re.TemperatureInCelsius());
			Serial.print(" T(F): ");
			Serial.print(re.TemperatureInFahrenheit());
			Serial.print(" T(K): ");			
			Serial.println(re.TemperatureInKelvin());
		}
}

If for some reason you want to power the sensor via a digital pin, you can just use another constructor

DHTSensor sensor(3, 7);//Will be using pin3 for collecting the data and pin7 for powering up the sensor

Disclaimer

There are several implementation of the DHT22 protocol out there but I decided to write my own so that I wipe the dust from my long forgotten C++ skills. I hope you will find this useful/educational.

Literature

In the literature directory you can find the full sensor specification sheet.