If you don't have Codey Rocky, just buy this device First, go to source code. Because you can only connect an device in the source code. You can choose upload or live mode. It is optional to attach or detach Codey (Unless you have a bluetooth dongle) To use the upload mode, connect the Codey Rocky that contains "COM". Then, press 'Upload' after connecting mBlock 5.0 or below: Click the 'Connect' button if you're ready. mBlock 5.5.1 or above Click the 'Connect' button. But make sure you need to download mLink first. (If mLink was selected) Click the serial button and select this device and connect it (If direct connection or serial was selected) You can now press the 'A' button to switch the battery type! Please note that delays and glitches may happen.