gk_ble_device_flutter 1.1.0

Bloc-based Flutter library to communicate with GK Concept devices via Bluetooth

This library enables the user to connect to a GK Concept device via Bluetooth Low Energy (BLE), to discover devices in the proximity and to subscribe to the device's report stream, notifying the application of the device's activity.

Currently, this library only supports Dropper devices with firmware 0.8.0 and later.

The library uses the Bloc library to separate business logic from the user interface.

Getting started

When using this library, please make sure to follow the FlutterBluePlus guide, in particular concerning the required permissions for your app.

Usage

All the core functionality is implemented in BleDeviceCubit.

A complete example with user interface can be found here.

Demo

This is what the example looks like on Android:

Multi device demo

This is what the multi device example (example/lib/multidev_main.dart) looks like on iOS:

Here we connect to ten Dropper devices simultaneously. Note that in particular during the initial setup, it takes some time to establish the connections, since all calls to service and characteristic discovery have to go through the flutter_blue_plus backend.

Initially, the device GKDR-DMGCXKJX3EDA was left powered off. Once all other devices are connected, we trigger the TOF sensors on GKDR-DMGCXKJX3ERQ and GKDR-DMGCXKJXFCIA to demonstrate how the reports from the devices are displayed as snackbars.

We then power up GKDR-DMGCXKJX3EDA to demonstrate the automatic connection to this device.

Finally, we disconnect GKDR-DMGCXKJXE76A from power and reconnect it to demonstrate that the automatic reconnection works.

Dropper report message format

The messages obtained from the report-stream subscription of a Dropper device have the following format:

{
  "#": 27,
  "date": "20-02-14",
  "time": "16:05:04",
  "timestamp": 1644854704,
  "report": true,
  "cycles": 2445,
  "doses": 35,
  "event": 2
}

With the following fields:

field	type	description
timestamp	int	UTC timestamp of the report (only relative if the system time was not set via WiFi)
event	int	event code:
		0 (POWERON) machine startup complete
		1 (DELIVERYREQ) request to distribute a dose
		2 (DELIVERED) distribution successful
		3 (PRIMEREQ) request to prime
		4 (PRIMED) priming done
		5 (UPDATEREQ) request to update firmware
		6 (UPDATEOK) update successful
		-6 (UPDATEFAIL) update failed
		-10 (NOHOMESW) failure to read home switch
cycles	int	Total number of distributions.
doses	int	Total number of distributions since last zero.

Permissions for macOS

For macOS, put the following in your Info.plist:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>The app uses bluetooth to find, connect and transfer data between different devices</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>The app uses bluetooth to find, connect and transfer data between different devices</string>

Also, add this to DebugProfile.entitlements and Release.entitlements:

<key>com.apple.security.device.bluetooth</key>
<true/>

Debugging

The BLE backend of this library provides control over the log level. This is demonstrated in main.dart of the example application.

FlutterBluePlus.setLogLevel(LogLevel.info);

If you need more detailed logs, you can change this to LogLevel.debug. The following screenshot illustrates what the debug-level logs look like when connecting to a Dropper device: