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.
PCB biz cards are a great gimmick – agreed. But they’re an even greater gimmick when they not only look cool, but sound great too! Check out the video below for audio of the stylophone in action!
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. A working midi controller, that’s unique enough in its playing characteristic to potentially give some value, while at the same time costing no more than the card would have done otherwise, since the keyboard is just a plated area on the PCB, as is true on the original stylophone.
To have the full range of 20 notes without using anything more than the ATtiny85, there’s only one real way of reading the keyboard, and that’s using the analog-to-digital converter with a resistor ladder along the keyboard. I took lots of inspiration from this excellent MIDI stylophone project including the very sensible idea of splitting the keyboard into two sections that are read on separate analog channels, to halve the required accuracy in the resistor arrangements.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.