question: public boolean writeCharacteristic ( String address , String serviceUUID , String characteristicUUID , byte [ ] value ) { BluetoothGatt bluetoothGatt = mBluetoothGattMap . get ( address ) ; if ( bluetoothGatt != null ) { BluetoothGattService service = bluetoothGatt . getService ( UUID . fromString ( serviceUUID ) ) ; BluetoothGattCharacteristic characteristic = service . getCharacteristic ( UUID . fromString ( characteristicUUID ) ) ; characteristic . setValue ( value ) ; return bluetoothGatt . writeCharacteristic ( characteristic ) ; } return false ; }
target:  Write data to characteristic, and send to remote bluetooth le device.