Bluetooth (Beta)
BLE support is currently in Beta. Some functionality is not available yet, and it may require further stability updates.
Compatibility Requirements
A custom-branded container is necessary for Android, iOS and Windows for any
Bluetooth functions. Please contact JourneyApps Support to request one.TypeScript is recommended
The
Bluetooth functions in JourneyApps rely on async-await. While it may be possible to work around this in a JavaScript app with promises, we strongly recommend using TypeScript.JourneyApps' Bluetooth Low Energy (BLE) support allows users to scan for and connect to nearby BLE devices in real-time. The simplest way to achieve this is using
Bluetooth.requestDevice(). For more advanced use cases, Bluetooth.requestLEScan() is available. More information on both these methods can be found below.Bluetooth.requestDevice() requests a device according to filters.On Web, a list of devices is returned to the user, from which the user can proceed to select one.
On Windows, Android and iOS,
Bluetooth.requestDevice() the first matching device is automatically selected. We recommend using Bluetooth.requestLEScan() (see below) on these platforms should the user need to select a device.view.ts
async function scan() {
const device = await Bluetooth.requestDevice({acceptAllDevices: true});
// To establish a connection to the device, use `device.gatt.connect()`
// Note: In many cases, no device name will be reported. We use this
// as a filter just to reduce noise for the example.
if (device.name) {
device.gatt.connect().then(() => {
console.log('Connected to ', device.name);
notification.info('Connected to: ' + device.name);
}).catch(err => {
console.error('Failed to connect to', device.name, err);
notification.error('Failed to connect to: ' + device.name);
});
}
}
Compatibility requirements
Bluetooth.requestLEScan() was introduced in version 4.84.0 of the JourneyApps Runtime. It is supported on Windows, Android and iOS only.Bluetooth.requestLEScan() should be used (instead of Bluetooth.requestDevice()) where the app needs more control over the BLE scanning process. It is based on this spec. Note the following differences from this spec:- 1.Added the
signalparameter to cancel scanning. - 2.Events do not include
manufacturerData,serviceData,txPowerorappearance.
Ensure that your TypeScript app has the following version in
package.json: "@journeyapps/runtime-build": "^2.0.2". Note that after updating package.json, you need to run Update yarn.Note that in this example the first device is being connected to. In a real app, you'd typically add these devices to a list (for example, you'd create LocalDB objects and display these in a suitable UI component) for the user to select one.
view.ts
// AbortController is optional, but makes explicitly stopping the scan easier.
// Scanning is automatically stopped when navigating to a different view.
let controller: AbortController;
async function scan() {
// Cancel existing scans, if any
controller?.abort();
controller = new AbortController();
Bluetooth.addEventListener('advertisementreceived', (event) => {
const device: journey.BluetoothDevice = event.device;
// Note: In many cases, no device name will be reported. We use this
// as a filter just to reduce noise for the example.
if (device.name) {
notification.info('Device: ' + device.name + ' ' + event.rssi);
// In a real app, you'd typically add these devices to a list,
// instead of connecting directly.
// To establish a connection to the device, use `device.gatt.connect()`
device.gatt.connect().then(() => {
console.log('Connected to ', device.name);
notification.info('Connected to: ' + device.name);
}).catch(err => {
console.error('Failed to connect to', device.name, err);
notification.error('Failed to connect to: ' + device.name);
});
}
})
await Bluetooth.requestLEScan({
// In most cases, you'd want to filter the devices instead, e.g.:
// filters: [{services: ['ffff0001-0b3a-11ec-9a03-0242ac130003']}]});
acceptAllAdvertisements: true,
// Set this to true to receive multiple events for the same device, e.g. to update the rssi
keepRepeatedDevices: false,
// We specify the signal to manually control stopping of the scan
signal: controller.signal
});
}
function stopScan() {
controller?.abort();
}
Last modified 4mo ago