DHT22/RHT03 Temperature driver

Introduction

The DHT22/RHT03 driver for Temperature sensors is used in conjunction with the DHT22/RHT03 sensor to measure the temperature of the sensor’s surroundings. The DHT22/RHT03 measures temperature through the use of a thermistor. The DHT22/RHT03 can also measure humidity via a variably resistant moisture absorbing substrate. Humidity and temperature measurements can be taken in tandem with each other. All data outputs are supplied via the data pin.


Driver Parameters

The DHT22/RHT03 Temperature driver for Temperature sensors has two parameters that need to be configured:

Pin

This is the pin is monitoring the change in temperature from the DHT22/RHT03, any pin is suitable as long as it is not already in use by another driver. However, it is possible to use the DHT22/RHT03 temperature and humidity drivers in conjunction with each other and both can be assigned the same data pin.

Resolution(F)/(C)

The resolution depends on the measurement system of the central core. If set to imperial, the resolution is in F (degrees Fahrenheit) and in metric it is in C (degrees Celsius).

The resolution in metric is ranging from 0 to 5 Celsius with a default value of 1.

The resolution in imperial is ranging from 0 to 9 degrees Fahrenheit with a default value of 1.

For example in in the metric system, if our latest reading was 25C and the resolution is set to 1.5, the builder base is not going to notify the central core unless the value is <23.5 or >26.5.


Wiring

Example

The GP0 pin is connected to Data Pin on the DHT22/RHT03, the 3.3V and GND pins on the Builder Base are then connected to the VCC and GND pins on the DHT22/RHT03.

 Breadboard 

 Schematic

Used Pins

Used Pins

Description

Used Pins

Description

GP0 (can be any GP pin)

This pin receives data from the DHT22/RHT03

3.3V 

This pin provides the power

GND

This pin provides the GND


How to write an App

Navigate to the App Builder and create a new application. You can find the “Temperature” code object under the “Hardware” Tab in the object drop down menu on the left, or you can also use the search bar.

 

 

 

Drag the “Temperature” Object onto the canvas.

Next, locate the “Text” Object under the Interface tab and drag it onto the canvas.

 

 

 

Finally, connect the “Temperature” port from the Temperature Object to the “In” port on the Text object and save your application.

 


How to create a firmware

Navigate to the Firmware Builder and create a new firmware file.

Click the “+ Add Hardware” button which will open a modal window. Scroll down in the list to find the “Sensor” section and select the “Temperature” hardware option.

Give your device a name, and click “Add Device”

 

 

 

Next, select the “DHT22” driver under the driver dropdown menu.

 

 

For this example we select:

  • Pin: GP0

  • Resolution: 1

 

 

You may now save your firmware file and upload it to one of your clients.

 

 

 


Supported Hardware

  • DHT22


Downloads

Apps

Firmware

Assets