Burger PCB

For my senior design project at UB, I'm building a hamburger vending machine. At the center of the build are custom PCBs - the brains that run the oven, freezer, conveyor belt, dispenser coils, and user interface. They're what make the whole thing run smoothly without a mess of loose wires or crazy compromises.

The big wins with going custom are handling higher current and taking full control over the motor drivers. Bonus points come from simplifying the wiring and baking in better fail-safes for food safety. The board is built for this task exclusively, so there's no wasted space and no unnecessary parts.

PCB schematic
 

I used KiCad for this project from start to finish, and found it really straightforward to use. There is a lot of documentation on the internet which made the learning process enjoyable, and going from concept to finished project only took a few hours. 

The trickiest part was picking the right symbols for each component, like the motors and buck converters, because almost everything had multiple wiring variations. I solved this by finding images from suppliers like eBay and McMaster Carr, seeing what connections were needed, and then selecting the appropriate symbol in KiCad.

Assigning footprints in the schematic

PCB editor

Here, connections are drawn between components, both on the PCB and connected extraneously. The components to be placed on the PCB are in the upper left, being the buck converter, microcontroller, resistors, and motor drivers. These control three buttons, two temperature systems, and four motors. External components connect cleanly, keeping the signal paths short and tidy.

Gerber and drill files

Seeing the Gerber and drill files for the first time was one of those “this is real” moments. Knowing that I could send them off to a manufacturer and, a week later, hold a copper-layer PCB is totally satisfying. More than that, it reinforced the full cycle of design. Going from concept, to schematic, to a board that can drive motors and manage safety-critical systems is why I love working with hardware.