Nixies and Raspis for a Modern Vintage Calculator

There are a few very rare and very expensive calculators with Nixie tube displays scattered about calculator history, but so far we haven’t seen someone build a truly useful Nixie calculator from scratch. [Scott] did just that. It’s a complete, fully-functional electronic calculator with all the functions you would expect from a standard scientific calculator.

The calculator uses IN-12 Nixies, the standard for anyone wanting to build a clock or other numerical neon discharge display. Each Nixie is controlled by a K155D driver chip, with the driver chip controlled by an I2C IO expander.

The keypad is where this gets interesting; electronics are one thing, but electromechanicals and buttons are a completely new source of headaches. [Scott] ended up using Cherry MX Blue switches, one of the more common switches for mechanical keyboards. By using a standard keyboard switch [Scott] was able to get custom keycaps made for each of the buttons on his calculator.

The brains of the calculator is a Raspberry Pi, with the I2C pins going off to listen in on the several IO expanders on the device. A Raspi might be a little overkill, but an Internet-connected calculator does allow [Scott] to send calculations off to WolframAlpha, or even the copy of Mathematica included in every Pi.

[Scott] has put his project up on Kickstarter. Videos below.

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Hacklet 17 – Keyboards

This week on The Hacklet we’re featuring some of the best keyboard hacks from Hackaday.io!

Hackers are really into their keyboards. Everyone has a favorite, and those favorites vary wildly. Mechanical, soft touch, ergonomic, QWERTY, DVORAK, chorded, you name it, there is a hacker, maker, or engineer who loves it, or absolutely hates it. For some, no commercial product is perfect. All is not lost though, as a custom keyboard is just a hack away!

ergo60

[Warren Janssens] gets things rolling with Ergo60, his 60 key ergonomic keyboard. [Warren's] layout is a pair of 25 key hand clusters, each with a matching 5 key thumb cluster. This layout minimizes lateral wrist movement. With the reduced key count and stacked keys, the user’s hands never move from the home row. [Warren] rolled his own PCBs for Ergo60. A Teensy 2.0 running a fork of TMK serves as Ergo60′s controller. [Warren's] is running Cherry Black switches and his keycaps are from Signature Plastics. [Warren] is using Ergo60 as his daily driver these days, so it’s no surprise that he’s set the “Completed Project” tag.

keycaps

Some say he needs no keyboard at all, and that his heartbeat sounds just like an IBM Model M. All we know is he’s called [Brian Benchoff]. [Brian's] created a pair of minimalist keyboard projects. The Unhappy Hacking Keyboard takes us back to basics. After all, computers run on 1′s and 0′s, right? What more could a person need? Apparently just a space and return. Unhappy Hacking Keyboard uses an ATtiny85 with V-USB as the controller and the interface. Keys are cherry MX blues. The keycaps are [Brian's] own Hackaday Cherry MX Keycaps printed by Shapeways.

zxkeyboardAn entire generation of hackers don’t know the joy of typing on a tiny rubber keyboard. [Alistair MacDonald] aimed to fix that, so he turned an old computer into a keyboard with his ZX Keyboard. [Alistair] started with a broken ZX Spectrum. He gutted the original electronics and added an Ardunio Pro Mini running the V-USB library. [Alistair] directly wired the row and column I/O lines from the keyboard to his Arduino. The result is a keyboard which is the perfect size for cell phones, Raspberry Pi’s and the like.

chordkey[Servo] teaches us new ways to type with Chordy KEY, his chording keyboard project. Chordy Key is meant to be used in the left hand. Five finger buttons and three thumb buttons are all that is needed to chord out 64 different letters and symbols. [Servo] utilized an ATmega32U4 powered Sparkfun pro micro to control his keyboard. Chordy Key is a proof of concept, but with [Servos's] use of 3D printed parts, Chordy Key looks like it’s ready for your next wearable computing project!

chord2[jmptable] is also working on a chorded keyboard design. Chord Keyboard uses only 7 keys to send the entire ASCII character set and a few control combinations. [jmptable] used an ATmega328P as his processor. Chord keyboard isn’t wired though. An RN-42-HID module provides bluetooth connectivity to the world.

[jmptable] has provided an amazing amount of detail on his research, including one of his goals of adding a chorded keyboard to the Gameboy Advance. They keyboard itself would be mounted on the spine of a game cartridge. We would love to see that idea come to fruition, [Servo]!

 

mightyFinally we have [Gertlex], who just wanted a scroll wheel embedded in his keyboard. He got there with the help of an Apple Mighty Mouse. Keyboard with Apple Mouse Scroll Ball is one of those hacks that looks like it original equipment. [Gertlex] took a drill to a Targus slim USB keyboard, putting a small hole right between the ESC and F1 keys. He fit the scroll ball from his Apple Mighty Mouse in the hole. Electronics are as simple as plugging the mouse and keyboard into the same USB hub. The only downside to the design is that [Gertlex's] keyboard doesn’t recognize fast enough to send key presses during the boot process.

That’s just about enough keystrokes for this episode of The Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Update – check our our keyboard list right here!

One man’s adventures in custom keyboard development

BlueCube-flat

As a software developer, [suka] spends a lot of time every day in front of a keyboard. He had been trying out different keyboard layouts far less common than even the moderetly obscure Dvorak layout, and after some time decided a custom ergonomic keyboard was what he wanted. His progress of designing his own custom ergonomic keyboard is a fascinating read, made even cooler by the fact these are real, professional-quality keyboards with mechanical switches and custom enclosures.

After starting off with a few USB numpads, [suka] dove in to the world of Cherry switches by crafting his own wing-style keyboard. [suka] works for one of the larger manufacturers of laser-sintering machines, so he was able to create the enclosures for his keybaord – as well as the key caps – fairly easily. The technology behind laser sintering allowed [suka] to create some strange bowl and trough-shaped keyboards before settling on his daily driver, seen above.

The Blue Cube, as [suka] calls it, includes an integrated stand, an integrated IBM trackpoint mouse, and is powered by a Teensy microcontroller. [suka]‘s keyboards might not be heafty enough for melee combat like the venerable IBM Model M, but it’s exactly what [suka] wants, and that’s just fine by us.

Kitchen scale key transplant

kitchen-scale-key-transplant

[Markus] is quite happy with his kitchen scale. It’s one of the tools he uses most frequently when cooking. But recently the button has begun to give him problems. He figures the years of spilling a little bit of this and that has mucked up the contacts. His solution was to bypass the button using a Cherry MX switch.

Really any replacement should do since the switch merely completes an electrical connection. But there’s a subset of hackers who swear by the Cherry MX switches that come in some keyboards. [Markus] had just such a keyboard on hand, which he was already using for parts, so he pulled out the switch and cut a hole in the scale’s case where he could mount it. After temporarily super gluing the switch in place he completed the task by filling the gap on the outside with hot glue, then running another bead of it along the inside. The addition of the ‘T’ key finishes the hack. The plastic key is easy to clean and will help shed flour, oil, or anything else he might spill during his culinary adventures.

This hack was fast and easy and may have convinced [Markus] to roll his own controller board for the device. We’ll keep a lookout for a follow-up post detailing those alterations.