Doubler Pinout

The Doubler Featherwing is fairly simple. It's 2.0" x 1.9" - the same as two proto Featherwings side by side with a 0.1" spacing in between (since there's slight variations on PCB routes, you dont want to have no spacing between them or plugged-in-feathers might jam)

Duplicated IO Pins

On the outer edges are all the pins you'd want to solder in to connect to the Feather. The inner set of pins are boxed and have small text or dots to indicate they are connected.  They are tied together so you have access to each I/O pin!

Also, both sets of IO pins are connected together

Power Rails

You also have two strips of holes that are all connected for 3.3V (left strip) and GND (right strip). This way you have plenty of power/ground connections available. The holes are 0.047" diameter and are connected with 32mil traces.

Note there's a thin strip of proto holes in between the 3V and GND rails

Proto Grid

Finally, there's a full set of prototyping grid, each hole is 0.047" diameter

Note there's a thin strip of proto holes in between the 3V and GND rails