Espruino Pico Adaptor PCBs

It's be both 0.1 and 0.05 - whatever makes sense really.

While stuff like the CC3000 is trivial to wire up with just 2 extra wires, I think a lot of people would still appreciate an adaptor - it'd only be around 1cm^2 area, so not too pricey.

• AT24/AT25 - do they use the same pinout? Something like that would definitely be handy.
  
• ULN2x03 - good point. I'd thought that the H-bridge might cover that, but actually just having pull-downs is handy sometimes.
  
• MOSFET - yes, again, it'd be a nice one to have.
  
  

The pins are pretty well finalised now. There's 1 I2C, 1.5 USARTs (RX/TX plus one extra RX), GND, 3.3v, 'Bat', and analogs - but no SPI. That's not such a big deal because a lot of the SPI stuff works fine with software SPI though.

I think every adaptor will be different - I'd just focus on trying to keep them small - stackability is probably secondary - but it'd be nice to be able to add extra adaptors onto the Arduino shield (the extra space could contain bluetooth/ESP8266/NRF24/etc pads as well).

I haven't tested the pins yet - but the Bat/3.3v/Gnd are at right-angles to the other pins, so should add some rigidity.

I mentioned on another post, but what do you think about PCB castellations? It's a little late on to add them, but it would be very cool - you could then put your Espruino Pico on your own board (or the Arduino adaptor) without any pins. It could be very low profile then.