Digirule 2U Is a New and Improved PCB Ruler for Old-School Computing

PCB rulers are great for traditional ruler tasks, like measuring things and acting as a straight edge. As a circuit board it’s possible to embed whatever information you need in text on the top and bottom of one, or even add lights and simple electronics. Some time ago, we covered the Digirule 2 by Bradley Slattery, which included an entire processor, lights, and buttons as a 1970s-inspired computing device.

While possibly the most advanced such ruler ever conceived, actually programming the device requires a lot of button mashing after you work out the binary instructions on a companion excel spreadsheet. Times have changed however, and as the Slattery's promo video notes, “the Digirule is keeping up with you.” The new Digirule 2U ruler is equipped with a micro USB port, allowing you to write a program in assembly language on a computer, compile it, and load it onto the ruler without a flurry of button mashing.

The Digirule 2U features a Microchip PIC18F45K20 MCU, along with a USB virtual COM port for communication. A serial debug monitor is built-in that can be accessed via a terminal program. The ruler is compatible with Windows, Mac, and Linux systems, and it can even link up with another Digirule 2U for more 8-bit fun.

Of course, you can still configure it with the onboard buttons, so in theory you don’t need a computer at all, just a bit of patience and dexterity! The Digirule 2U is now funding on Kickstarter, starting at around $27 for a single ruler, with estimated delivery in January 2021.