Printed Circuit Boards!

We just started to learn about making Printed Circuit Boards! (PCBs)!

A handy program called "fritzing" lets us design the holes and electrical connections on the board where we'll solder in various electronic components – sensors, lights, resistors, a chip to control motors – and then some pins to connect with a microprocessor.

The microprocessor brains – an "arduino Uno R3" – will have access to whatever is plugged into the rest of the PCB. I could potentially write all sorts of programs to do different combinations of things with that stuff. Mmmmm, things and stuff... that's so exciting. Currently, I'm considering things like a 3D scanner, automatic blinds, a motorized tracking camera mount, and various autonomous vehicles.

Below are images that represent how the two sides of the PCB will sort-of look. This process is like planning a bunch of highway interchanges and overpasses in the sense that the connections can be routed through the board to avoid each other on opposite sides. Compared to a mess of wires, the benefits of a PCB include durability, compactness, and easier connection.




This PCB design will enable a chip in the middle, called an "H-Bridge," to control two motors in two [potentially different] directions, and some lights will be able to show a range of status information. Holes on the edges will fit pins for connecting with the brainiac arduino, and others will allow wiring all the sensors and motors.

This custom PCB will be manufactured by cutting out connection lines from a copper sheet – essentially flat wires. The copper sheet is adhered to a circuit board, and a very precise little machine called a "CNC Mill" will grind off all the copper we choose without cutting through the plastic-y "board" portion of the "circuit board." Think of a small "Dremel" grinder tool riding on a computer printer head – that's almost like to a Computer-Numerically-Controlled Mill.

Note that large-scale production of PCBs would typically leverage different manufacturing processes that use chemicals to do the same job much more quickly. This particular method will probably take the better part of an hour to carve out. That's okay with me.

I almost have my board design completely figured out... but I want to sleep on it and see if a fresh look tomorrow will bring new ideas for cramming on additional components. I'll post photos as soon as I tell the machine to do its thing.