MetaWearBoard¶
The MetaWearBoard interface is a software representation of the MetaWear boards and is the central class of the MetaWear API.
Bluetooth LE Connection¶
Before using any API features, you must first connect to the board with
connectAsync. The returned task will
finish when a connection has been established and the MetaWearBoard state has been initialized.
board.connectAsync().continueWith(new Continuation<Void, Void>() {
@Override
public Void then(Task<Void> task) throws Exception {
if (task.isFaulted()) {
Log.i("MainActivity", "Failed to connect");
} else {
Log.i("MainActivity", "Connected");
}
return null;
}
});
Conversely, call
disconnectAsync to close the connection.
If there is a pending connectAsync task when disconnectAsync is called, the connect task will be cancelled.
board.disconnectAsync().continueWith(new Continuation<Void, Void>() {
@Override
public Void then(Task<Void> task) throws Exception {
Log.i("MainActivity", "Disconnected");
return null;
}
});
Unexpected Disconnects¶
Sometimes the BLE connection will unexepectedly drop i.e. the BLE connection was not closed by the API. Call onUnexpectedDisconnect to register a callback function to handle such events.
board.onUnexpectedDisconnect(new MetaWearBoard.UnexpectedDisconnectHandler() {
@Override
public void disconnected(int status) {
Log.i("MainActivity", "Unexpectedly lost connection: " + status);
}
});
Model¶
Despite the name, the MetaWearBoard interface communicates with all MetaSensor boards, not just MetaWear boards. Because of this, the interface
provides a getModel method that determines
exactly which board the interface is currently connected to.
Log.i("MainActivity", "board model = " + board.getModel());
BLE Information¶
RSSI and some GATT characetristics (battery level, device information) can be read from the MetaWearBoard interface using readRssiAsync, readBatteryLevelAsync, and readDeviceInformationAsync respectively.
board.readDeviceInformationAsync()
.continueWith(new Continuation<DeviceInformation, Void>() {
@Override
public Void then(Task<DeviceInformation> task) throws Exception {
Log.i("MainActivity", "Device Information: " + task.getResult());
return null;
}
});
Modules¶
MetaWear modules, represented by the Module interface, are sensors, peripherals, or on-board firmware features. To interact with the underlying MetaWear modules, retrieve a reference to the desired interface with the getModule method. A null pointer will be returned if any of the following conditions are true:
Requested module is not supported on the board
Board is in MetaBoot mode
Has not yet connected
A variant function, getModuleOrThrow will throw a checked exception in lieu of returning null.
import com.mbientlab.metawear.module.Led;
Led led;
if ((led= board.getModule(Led.class)) != null) {
led.editPattern(Led.Color.BLUE, Led.PatternPreset.BLINK)
.repeatCount((byte) 10)
.commit();
led.play();
}