question: public void writeCharacteristic ( String serviceUUID , String characteristicUUID , String value ) { if ( mBluetoothGatt != null ) { BluetoothGattService service = mBluetoothGatt . getService ( UUID . fromString ( serviceUUID ) ) ; BluetoothGattCharacteristic characteristic = service . getCharacteristic ( UUID . fromString ( characteristicUUID ) ) ; characteristic . setValue ( value ) ; mBluetoothGatt . writeCharacteristic ( characteristic ) ; } }
target:  Write data to characteristic, and send to remote bluetooth le device.