DHT22/RHT03 (Low Energy) Temperature driver
Introduction
The DHT22/RHT03 (Low Energy) 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. This device supports ultra low energy mode and is only powered conditionally.
Driver Parameters
The DHT22/RHT03 LE Temperature driver for Temperature sensors has three 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.
Power Pin
This pin is selected to provide power to the DHT22 only during reading. This way we preserve power in the remaining time.
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/RTH03, the GP1 pin is connected to VCC on the DHT22/RTH0 and GND pin on the Builder Base is then connected to the GND pin on the DHT22/RTH03.
Breadboard
Schematic
Used Pins
Used Pins | Description |
|---|---|
Any GP pin | This pin receives data from the DHT22/RTH03 |
Any GP pin | 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/RHT03 Low Energy” driver under the driver dropdown menu.
For this example we select:
Pin: GP0
Power Pin: GP1
You may now save your firmware file and upload it to one of your clients.
Supported Hardware
DHT22
Downloads
Apps
Firmware
Assets