I've finally completed the V0.2 PCB design!

This version includes :

• a USB port (USB B, because I hate all of the smaller USB jacks).
• a headphone jack.
• a new power switch that switches both power and ground, batteries properly in series.
• diodes to allow batteries and USB to be attached at the same time and let the unit be powered by USB.
• a fix for the lack of pins for the MODE button.
• capacitors on all of the WS2812B RGB LEDs.

Whew!

Here is a lovely 3d render. Note that it shows all thru-hole components mounted in most places, but rest assured that I actually have an option for surface mount parts for manufacturing. The thru-hole parts are used in the 3d render because those are larger and the case needs to be constructed around them because they are going to be harder to fit.

Back side of the board shows the new capacitors on the LEDs, and the USB and headphone jacks. 

The USB port and headphone jack are optional; they can be removed to get the price down, although saving a dime seems silly here.  Note that there is a little extension on the board for the headphone jack; that is because I now know that the boarder on the case is going to be at least 7mm, and it sticks out from the PCB so that the jack won't be recessed too far inside the case. Likewise, the edge location of the USB port.

Also, the batteries have been moved as far to the left and right of the board as possible, and all of the amplifier circuitry has been moved out from behind the batteries. Mostly, this makes it possible to mount the batteries to the PCB if one is using it without a case.

Finally, all of the battery and speaker connectors have been changed to vertical pin headers to make them a little easier to fit; there were a lot of problems before with the speaker connection getting stuck under the bezel

I've also prepared a parts order for AliExpress that I have posted  for approval. I hope to get that order out by tomorrow. 

While I wait for parts, I'll be getting back to working on the software.