Rotary Dialer Becomes Numeric Keypad

July 30, 2020 by Lewin Day 4 Comments

Many laptops eschew the numeric keypad to free up space, and some desktop keyboards have taken on the trend, too. If you want a specialised numeric entry device and have absolutely no interest in speed or ease of use, [jp3141] has just the build for you.

The idea is to use the rotary dial from an old telephone to enter numbers into a computer. It’s slow and cumbersome, but it’s also pretty entertaining. The build uses an old AT&T Trimline dialer, though we’re sure most rotary phones would work. The pulses produced by the dialer are counted by a Teensy microcontroller, which emulates a USB HID keyboard device and enters the relevant keystroke into the computer. There’s also a USB serial interface for debugging, and an LED which flashes along with the pulses from the dialer circuit.

While it’s not the most efficient data entry method, it’s a semi-useful way to repurpose an old phone, and an amusing piece to take along to your next LAN party. We’ve featured a few… alternative… keyboards before, too. If you’ve cooked up a truly convoluted input device for your computer, be sure to let us know.

Sawed Off Keyboard

September 18, 2017 by Steven Dufresne 45 Comments

Have you ever had to cut a piece of furniture in two to get it into a new place? Yours truly has, having had to cut the longer part of a sectional sofa in two to get it into a high-rise apartment. That’s what [Charles]’ sawed off keyboard immediately reminded us of. It sounds just as crazy, but brilliant at the same time.

In [Charles]’ case he wanted a keypad whose keys were customizable, and that would make a single keypress do common things like cut, copy and paste, which are normally ctrl-X, ctrl-C and ctrl-V in Windows. To do that he literally sawed off the numeric keypad from a full-sized keyboard. He also sawed off the end to the left of the QWERTY keyboard, and glued it onto the open end of his keypad.

The circuit board was too wide to fit in his new keypad, but he couldn’t stretch out the connections from the keypad’s keys to the board. So he did what any self-respecting hacker would do, he cut the circuit board where there were a manageable number of traces, leaving one part that would fit inside the keypad and another part that he could connect the traces to using a few wires. Lastly, he’d started with a PS/2 keyboard but he wanted USB output and programmability. So he redirected the PS/2 wires to an Arduino compatible Pro Micro and wrote some conversion code which you can find on his GitHub.

What other transformations can we do to keyboards? [Shrodingers_Cat] combined his with some DVD case covers to come up with a pedal board for use with his feet. And given that the keys on the numeric keypad are redundant, [Kipkay] put it to use as a hiding place for valuables instead.

Hackaday Links: February 12, 2012

February 12, 2012 by Brian Benchoff 16 Comments

This is why digital picture frames were invented

[Petros] sent in this video of his visualization of Van Gogh’s Starry Night. He did this with openFrameworks and also made a version that reacts to sound. Is anyone else reminded of that one scene in Vincent and the Doctor?

A boat’s a boat, but a mystery box can be anything

[Rick] wanted to build a lock pick training station for the Eugene Maker Space, but he needed a way to make it interesting. What could be better than a mystery box? When you pick the deadbolt, open the box up and you’ll get a prize. Just make sure you put something of yours in the box for the next person.

3D printer prints its own case

Because the 3d printer community isn’t segmented enough, [Sublime] decided to design a new one. Here’s where it gets cool: the Tantillus can print its own case, and can ‘daisy chain’ to another Tantillus so only one set of electronics are needed. Interesting ideas afoot.

A diamond says I love you, but a duct tape rose says I’ll fix that for you

Valentine’s Day is coming up, so if you haven’t already made dinner reservations, you’re probably up the creek. How about making a duct tape rose for that special person in your life. Bonus: a dozen costs $3, and they won’t die in a week.

Using keypads over serial or SPI

[Leniwiec] sent in a tutorial on connecting keypads to a microcontroller with a serial or SPI interface. If you want to build a calculator, this is your chance. We’d use this for an Apollo Guidance Computer, though.