Restore Synthia's firmware
Once you're done coding and just want your Synthia to be "normal" again, you need to restore its base firmware.
This is quite simple, just connect your Synthia to the USB port of your computer and press the "Restore firmware" button on the top right.



You will be prompted with a window to choose the device you are restoring the firmware for.
Choose Synthia, of course.

Wait for a few seconds, and your Synthia will be back and running like usual.
You need to do this whenever you're done coding your Synthia if you want it to revert to its initial out-of-the-box functionality.