PiggybackPiggyback is an RP2040-based controller board with three built-in 5-pin MX switch footprints. Similar to the Postage Board Mini, but now with the power of the RP2040, castellated edges, and a removeable USB port.
When the USB port is removed, it can be inserted co-planar with a sister PCB, making it trivial to design an "integrated" PCB (as opposed to a PCB that uses a pro-micro), without having to place and route the complicated components of the MCU.
A Kicad symbol and fooptrint make it easy to implement into new designs, and leave only diodes to be assembled on the sister PCB if the board uses the ezMate uDB connector.
The USB data and power lines broken out to the removable USB-C port, an ezMate connector for USB daughterboards, and to the castellated edges where they can be routed to the sister PCB's own USB implementation.
All 30 of the RP2040's I/O is broken out to the edge connector, with 4 of them being used as the columns and row of the 3 built-in switches.
Prototypes have be produced, and are confirmed fully functional.
I would love to hear your feedback, and know what you would like to see changed. The idea is to have these available to folks wanting to do cheap on-off or low-quantity PCB runs, or for hand-wiring a board without adding the thickness or size of a pro-micro.
I am also looking for potential interested international vendors.
