Stephen Hawes' Piggyback Board Adds Control for Up to 32 Feeders to Any OpenPnP Pick-and-Place

Stephen Hawes has developed an add-on board for the OpenPnP pick-and-place project, dubbed the Piggyback, which controls up to 32 part feeders — and is based around an ATmega32U4 microcontroller.

Many maker projects are built entirely by hand in single or at least single-digit quantities, where physically picking up the parts and placing them for soldering is straightforward. For larger-scale projects, or those which use smaller components, a pick-and-place machine is a great aid — and the OpenPnP project remains one of the most popular for open hardware implementations of these tools.

"So I built a feeder for my pick and place, but how to I control it? And what about when there's THIRTY of them!? Herein lies the answer," writes Hawes. "I designed a board I'm calling the Piggyback board that lets OpenPnP control up to 30 (well actually 32) feeders. It uses an ATmega32U4, along with a whole bunch of I/O expanders so I have a bunch of pins to use. I thought this board was going to be easy, but it was a real toughie!"

Hawes' 15-minute video walks through the design and creation of the Piggyback board, but while it shows the board controlling a feeder for surface-mount technology (SMT) parts it doesn't show the pick-and-place machine actually using them. "The next [video] will probably be rebuilding the entire pick-and-place from scratch," Hawes jokes, "so that the nozzle can actually pick components off the feeders!"