Closing it UpYou will need to neatly fit the GEMMA, lipo battery and the JST/switch adapter into the box. For an easier build, try using a 110mAh lithium polymer battery (the 150mAh is a little more tricky to fit into the box, but it can be done!). Place the battery in between the Gemma and led matrix.
If the cover doesn't quite close, you may need to reduce the length of the battery cable and/or the JST/switch adapter. With patience, trial and error, you're box will nicely close shut with a little wiggle room.