A simple demo flutter application that shows how to communicate with a Sensirion smart gadget.
The app supports scanning for smart gadgets, connect to gadgets and read the temperature and humidity characteristics, as well as disconnecting from smart gadgets.
The app requires a smart phone with bluetooth low energy support to work.
Turn on bluetooth and click on the scan button on the bottom right to scan for near-by smart gadgets. A list of gadgets found is displayed. Scanning again will clear the current list and disconnect from all connected gadgets at the moment.
Click on a smart gadget to show the detail screen and connect to the gadget, if not already connected. On the detail screen you will see the current temperature, humidity and connection status.
Long press on a connected gadget in the list view will disconnect from that gadget.
This app uses redux to manage the data flow, and the flutter blue plugin to handle the bluetooth stack.
All bluetooth related code can be found in ble_middleware.dart.
Currently we register two characteristics of the smart gadget:
- Temperature
GUID('00002235-b38d-4985-720e-0f993a68ee41') - Humidity
Guid('00001235-b38d-4985-720e-0f993a68ee41')
The values we receive from those characteristics arrive in little
endian. To extract the double values we use the following code, which
is located in little_endian_extractor.dart:
static double extractDouble(final List<int> value) {
var data = new ByteData.view(Uint8List.fromList(value).buffer);
return data.getFloat32(0, Endian.little);
}
For help getting started with Flutter, view the online documentation.