The printed circuit board (PCB) based ruler has been around for awhile now, with one of the most popular being introduced by Adafruit (shown first, below) several years ago. PCB materials are inexpensive and can be fabricated into custom designs by numerous board firms. The rulers most often have useful information printed or etched on each side, giving them some geek cred in addition to usefulness and style.
Custom versions of the Adafruit ruler have been made in conjunction with Mouser and Digikey, in each companies signature colors.
With the Adafruit design being Open Source, there have been imitations, mostly from abroad. Knockoffs, without the Adafruit logo, are available on AliExpress from China and on eBay.
Some folks including Seeed Studio, nVidia, eevBlog and many others have designed their own PCB rulers in differing sizes with various helpful information on each side.
The Digilent ruler, above, is interesting as it is also a prototyping board for projects.
Not long after Adafruit’s original ruler introduction, Hackaday featured a very crafty digital logic ruler, by Brad, called DigiRule. This PCB ruler also contained a microcontroller and LEDs which simulate digital logic including gates, flip flips, and binary counting. It was offered as a Kickstarter and is still available from Brad on Tindie.
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.
“You can also ask the manufacture for other colours aside from green. Here is my friend’s University of Waterloo PCB Ruler, created with black solder mask and gold plating (black and gold are my school’s colours):”