Custom Num Pad Does Double Duty As Macro Pad

Why buy a num pad or a macropad when you can build something new and beautiful, open source that bad boy, and be a hero to the community? We think that should be all the justification you ever need to build instead of buy, even if you think your thing is Just Another Keypad [JAnK] as [Clewsy] claims.

At first glance, JAnK appears to be a standard number pad with four macro keys across the top. But when you roll your own ‘board, all the keys are programmable. [Clewsy] took advantage of this by adding a second layer that’s accessible with (what else?) the Num Lock key. This switches JAnK over to 21-key macro pad mode.

[Clewsy] rolled their own PCB for this and used the venerable ATMega32u4 because of its HID and USB host capabilities. Every key is backlit, and these LEDs are driven by an MP3202 LED driver and PWM from the AVR. [Clewsy] was able to build a prototype by sawing the num pad off of a stainless steel key switch plate from another build, but eventually ordered JAnK its own custom, laser-cut, stainless steel plate. The lovely enclosure is made of spotted gum wood and an acrylic base.

Putting it all together proved to be a bit problematic. [Clewsy] soldered up the minimum viable components for testing and discovered that the ATMega’s VCC and GND pins were both shorted. This killed the AVR programmer, but not the chip itself, and [Clewsy] happened to have a spare. To add insult to injury, the Num Lock light didn’t work, but [Clewsy] was able to simply reverse the LED instead of ordering a new pile of boards. Check out the detailed write-up with code and tons of pictures over on [Clewsy]’s personal site.

One of the awesome things about this build is that [Clewsy] was able to re-use the code from macr0, which began life as a proof of concept for scanning key matrices, and retired to become a music and media controller.

Lower Productivity By Using A Rotary Num Pad

[Maximilian Ernestus] sent us a quick little demo that shows him using a rotary phone dial as a num pad. We’re often frustrated when notebooks and netbooks prohibit us from using our mad 10-key skills (alternate key mapping doesn’t count). This makes coding and using GnuCash undesirable on small form factor portables.

Instead of fixing the problem, [Maximilian] made it worse by interfacing a rotary phone as a num pad. An Arduino counts the pulses and feeds them to the computer via a serial connection.  From there it’s just a bit of software handling to issue a keypress.  He mentions that a future version should register as a USB keyboard. This is a great opportunity to ditch the Arduino and use the V-USB library.

Want to dig a bit deeper into this old technology? Don’t miss out on the information available from the Magic Phone hack.