Hobnobbing With The Knob

February 15, 2023 by Al Williams 22 Comments

The scroll wheel might be the best thing that happened to the computer mouse since, well, the computer mouse. But sometimes you want something a little more tangible. For example, with a software-defined radio setup, it doesn’t feel right to scroll your mouse to change frequencies. That’s where [Wagiminator]’ USB knob would come in handy. Marrying a 3D printed case, some addressable LEDs, a rotary encoder, and a CH552E microcontroller, the knob appears to the host operating system as a normal USB keyboard. That means most programs can use it without any special drivers or software.

There’s honestly not much to the hardware. A custom PCB holds two WS2812’s, the tiny CPU, the encoder, and the USB plug. There are a few random discrete components, too, but not many. Everything you need is on the project page. The PCB layout, the software, the schematics, and the 3D print files. The code that does the main work is extremely simple. The USB code is a bit more complex (look in the include directory) but honestly, it isn’t as bad as most USB examples we’ve seen.

This project is ripe for hacking. The software is simple enough to modify easily. The 3D printed case wouldn’t be hard to spruce up or print in different colors. Following the example, this would make a reasonable core for a custom keyboard peripheral that used exotic keys instead of a rotary encoder.

Knobs can be simple or complex. If you want our take on the odd volume control, we used sonar.

A couple of joysticks wired up to a Teensy for prototyping.

Custom Joystick Build Guide Should Point You In The Right Direction

September 8, 2021 by Kristina Panos 12 Comments

Over the last two years, [benkster] has been perfecting their ideal flight controller. Like many people, they started out with a keyboard and mouse and eventually moved on to a joystick. While a HOTAS (hands on throttle-and-stick — e.g. a yoke controller with inputs right there on the sides) might have been the next logical step, those things cost too much. Naturally, the answer is to build one, ideally for less money. Hey, it could happen.

The design went from just an idea to a cardboard prototype, and then to a wooden enclosure and later, a 3D-printed case. Since [benkster] learned a great deal along the way, they want to give back to the community with a comprehensive joystick design/build guide so that others don’t have to start from zero, overwhelmed with information.

[benkster] wanted three joysticks, a bunch of big buttons, a throttle, a display to show component status (as in, is joystick #3 a joystick right now or a WASD keyboard?), and immersive details everywhere — you know, a million buttons and switches to give it that cockpit feel. [benkster] is using a Teensy 4 to control two 3-axis joysticks and one 2-axis stick. Since this adds up to too many axes for Windows/DirectX to read in, the 2-axis stick is used as a WASD keyboard.

This guide is a great place to start, especially for folks who may be newer to electronics. There are nice introductions to many types of components and tidbits that are relevant outside the world of joysticks.

You want immersive flight simulation away from the PC? Here’s a printable flexure-based ‘stick that snaps right on your Xbox controller and pushes the buttons.

MIL-SPEC Keyboard Now Salutes USB

February 27, 2020 by Kristina Panos 6 Comments

When [easyjo] picked up this late ’80s Marconi mil-spec keyboard for cheap, he knew it wouldn’t be easy to convert it to USB — just that it would be worth it. Spoiler alert: those LEDs aren’t a mod, they’re native. They get their interesting shape from the key traces, which are in the four corners.

Despite having way-cool buttons such as WPNS HOLD, and the fact that Control is on the home row where it belongs, this keyboard does not look fun to type on at all for any length of time. Of course, the point of this keyboard is not comfort, but a reliable input device that keeps out dust, sweat, liquids, and the enemy.

This is probably why the controller is embedded into the underside of the key switch PCB instead of living on its own board. [easyjo] tried to analyze the signals from the existing 26-pin connector, but it didn’t work out.

So once he was able to decode the matrix, he removed the controller chip and wired the rows and columns directly to an Arduino Leonardo. Fortunately, the LEDs were just a matter of powering their columns from the front side of the board.

The availability of certain kinds of military surplus can make for really interesting modernization projects, like adding POTS to a field telephone.

Via r/duino

Hackaday Prize Entry: Unlock Your PC The RFID Way

October 18, 2017 by Jenny List 21 Comments

Sometimes we see projects whose name describes very well what is being achieved, without conveying the extra useful dimension they also deliver. So it is with [Prasanth KS]’s Windows PC Lock/Unlock Using RFID. On the face of it this is a project for unlocking a Windows PC, but when you sit down and read through it you discover a rather useful primer for complete RFID newbies on how to put together an RFID project. Even the target doesn’t do it justice, there is no reason why this couldn’t be used with any other of the popular PC operating systems besides Windows.

The project takes an MRFC-522 RFID module and explains how to interface it to an Arduino. In this case the Arduino in question is an Arduino Pro Micro chosen for its ability to be a USB host. The supplied code behaves as a keyboard, sending the keystroke sequence to the computer required to unlock it. The whole is mounted in what seems to be a 3D printed enclosure, and for ease of use the guts of the RFID tag have been mounted in a ring.

As we said above though, the point of this project stretches beyond a mere PC unlocker. Any straightforward RFID task could use this as a basis, and if USB is not a requirement then it could easily use a more run-of-the-mill Arduino. If you’re an RFID newbie, give it a read.

Plenty of RFID projects have made it here before, such as this door lock. And we’ve had another tag in a ring, too.

Tweet Messages From Punch Cards

November 21, 2014 by Theodora Fabio 19 Comments

It all started with a conversation about the early days of computing. The next thing he knew, [Tim Jagenberg’s] colleague gave him a stack of punch cards and a challenge. [Tim] attempted to read them with a mechanical contact and failed. Undeterred, he decided to make a punch card-to-keyboard interface using optical parts from disassembled HP print stations. Specifically, he took apart the slotted optical interrupter switches to use their IR-LEDs and photo-transistors. Next, [Tim] drilled holes into two pieces of plastic, gluing the LEDs on one piece of plastic and the photo-transistors on the other. The photo-transistors tell the Teensy 3.1 whenever a hole is detected.

[Tim] developed an interpreter on the Teensy that reads the punch card according to IBM model 029 keypunch codes. The Teensy enumerates as a USB keyboard when connected to a computer. As a punch card is read, the Teensy outputs the decoded characters as key presses. When a punch card has been completely read, an ‘Enter’ key press is transmitted. Tweeting the punch cards is no more complicated than typing the text yourself. Naturally, the first message posted on Twitter from the stack of punch cards was “Hello World!” [Tim’s] binary and source code is available for download on Github.

We’ve enjoyed covering the backstory of the punch card and a previous project reading these cards using a digital camera setup. It’s always interesting to see the clever ways people use current technology and can-do attitude to read data from obsolete systems that would otherwise be lost. We wonder what is on the rest of those punch cards? Let’s hope [Tim] has more punch card tweets soon!

USB Dongle Generates And Enters Your Passwords So You Don’t Have To

March 5, 2012 by Mike Nathan 45 Comments

usb-password-dongle

Like many businesses out there, [Joonas Pihlajamaa’s] employer requires him to change his password every few months. Instead of coming up with a complex, yet easy to remember password again and again, he built a small USB device to do the work for him.

He dismantled an old USB memory stick, fitting it with an ATtiny85 with its required components on a small piece of perfboard. Using the knowledge he gleaned from his previous USB HID tinkering, he programmed the ATtiny to act as a USB keyboard which enters his password for him whenever he plugs it in.

The USB dongle not only types his password in for him, it can generate a new password with a few simple keystrokes whenever he desires. Obviously it merely takes someone getting their hands on his USB stick to compromise security, but it does beat a Post-It under the keyboard any day.

Continue reading to see a short video of his USB password dongle in action, and be sure to swing by his site for more details on how it was all put together.

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