Printed Circuit Boards as a business card are a great gimmick. I’d seen ones with USB ports etched into them, which enumerate as a keyboard and then type a person’s name or load up their website. It’s just about possible to build them cheap enough to hand out as a business card, at least if you’re picky about who you give them to.
A couple of years ago I took a stab at making one for myself, but I didn’t want it to be pointless. I wanted it to do something useful! Or at least entertain someone for longer than a few seconds. I can’t remember quite how I got the idea of making a MIDI-stylophone, but the idea was perfect.
I have had a need for a distribution amplifier for a while now. Searching around I found the design by G4JNT in Radcom, which filled my needs. I redrew the circuit for 4 outputs and had PCBs made. (if you want one contact me!) I now have the units in my M1DST 10MHz Thunderbolt monitoring project and in my LPRO101 10MHz Rubidium source.
Continuing the DIY Arduino tutorial series, this AddOhms episode shows how to create a PCB in KiCad. I make a joke that the original design was a rectangle, which I found boring and pointless. So instead, I designed a triangle to give the board 3 points. Get it? Puns! I am calling it the Pryamiduino. To be honest, I found not having a constraint to be a problem. By forcing a specific board size and shape, many decisions were more manageable.
A while ago I added the hall effect encoder IC I’ve been using directly to the motor controller PCB. The controller sits directly on the back of the motor (with a magnet added to the motor shaft), and the phase wires solder straight in. I also have a pair of board-mounted XT30 connectors on the DC bus for easy daisy-chaining. Otherwise, the board is basically identical to the previous version of this controller. I’ve now built over a dozen of these, and have had no problems.
So I posted a while back about how I had used these 22mm pcb’s I’d made in prototyping an ematch ignitor system for use in rocketry. Although I made these stackable boards so they would fit inside a popular size of Estes rocket body tube I’m aware that they are quite useful for lots of things. So i’ve open sourced them so anyone can get some made, or add improve or change them.
There are three boards,an Attiny85 board with some power LED and indicator LED, a SOT89 power supply board which could be built up with either a 3.3v or a 5v supply. Finally there is a “kludge” board which is useful for adding in some thru hole components into the system. Some quick pics here but in the files on Git each board is well documented in a pdf. All the dust components are 0805 so super accessible for hand SMD soldering. :)