问题
My application needs to constantly get RSSI value of a bluetooth device to make some distance-rssi approximation, without connecting. However, callback method of the BluetoothAdapter gets the RSSI only once when the device scanned.
// Device scan callback
private BluetoothAdapter.LeScanCallback leScanCallback = new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
runOnUiThread(new Runnable() {
public void run() {
...
}
});
}
};
As a solution, I created two Runnable objects. One is for starting, other is for stopping scan process. These two objects call each other continuously until I get my desired RSSI value. After that my Handler removes them from message queue.
private Runnable startScan = new Runnable() {
@Override
public void run() {
bluetoothAdapter.startLeScan(leScanCallback);
scanHandler.postDelayed(stopScan, SCAN_INTERVAL);
}
};
private Runnable stopScan = new Runnable() {
@Override
public void run() {
bluetoothAdapter.stopLeScan(leScanCallback);
scanHandler.postDelayed(startScan, STOP_INTERVAL);
}
};
This seems to be working but I want to know if there is more viable option to do this without connecting.
回答1:
If the ble beacon is advertising and not connectable, onLeScan is called continously. If the ble beacon is connectable, the feature depends on the device.
来源：https://stackoverflow.com/questions/20058450/how-to-continuously-get-rssi-without-connecting-to-the-ble-device