A papercraft resistor calculator from Adafruit

The Adafruit blog just posted a neat papercraft resistor calculator. If you haven’t yet learned the horribly offensive mnemonic for resistor color codes, now’s your chance to have a cheap and portable resistor value reference.

This papercraft resistor calculator is the latest in the family of Circuit Playground tools that include a fabulous electronic reference app we reviewed some months ago. Instead of an Android or iOS device, the papercraft resistor calculator runs on its own mechanical computer; a series of four printed disks and some paper fasteners.

If you’d like to print out your own resistor calculator, Adafruit put up the PDF on GitHub and posted the Illustrator file on Thingiverse for easy editing. It’s not the old-school cool of a slide rule, but we could easily see this resistor calculator being useful if you’re ever lucky enough to teach electronics to children. At least then you won’t have to share that offensive mnemonic.

Slide rule for musical scales

For all those engineers who dabble in music [Magnetovore] has your back. Musicians simply must know their scales and he came up with a papercraft slide rule for major and minor scales.

The system is very easy to use. He’s uploaded PDF files that let you print out the mask for the top layer and bar chart and directions for the bottom layer. The top layer is laid out like a piano keyboard, with windows for each key and a couple of windows to identify the major and minor scales being displayed. Just slide the mask until each key is a solid color. The color codes show the tonic, third, and dominant for each key so you know where to start. In the video after the break you can see how it works by playing all of the non-black keys in order. But wait, if you order now you’ll get the slide rule for Cello scales at the same low-cost; free!

This is a fun quick-reference, but you really should know your Circle of Fifths. [Read more…]

Piano Box is a digital synthesizer made of paper

We love the look of this papercraft piano which [Catarina] built along with some friends at NYC Resistor, a hackerspace in the big apple. It starts off as a cubic black box with a white top. But just lift that top as [Catarina] does in the video after the break and three of the sides fall flat to reveal a pair of speakers and the single-octave keyboard.

The key’s don’t move when you press them. Instead, she decided to use the CapSense Arduino library to implement touch sensitive keys. Each key is made up of a plane of copper foil tape, with a strip of tape running back to the center of the box where it is interfaced with an Arduino Mega hidden there. The Tone library produces the waveforms which are played by the speakers, and a set of LEDs on the upright side of the box illuminate the keyboard diagram as you press each key. You can see that there are short white bars on that display which correspond to the black keys on the keyboard.

If you take a look at the code, you’ll see the libraries really make the code for the project simple.

[Read more…]