MDBT42 + breakout

Personally I think the nRF52840 is just a nRF52832 with more flash and RAM - but I wonder whether you need it? I mean, it's not like people are really running out of memory with Puck.js at the moment.

It definitely won't be the same price as the 32 either :)

In terms of a board, I'd say:

• Place to solder a CR2032 battery
  
• 0.1" pins
  
• Pins for serial in the 'standard' FTDI pinout
  
• Maybe a snap-off area at the end with an NFC aerial?
  
  

Any thoughts about a 3.3v regulator? It'd mean you could run it off of 5v or a LiPo, but it would also draw power, so would reduce battery life.