Pen input has never really taken off in the computing mainstream, though it’s had somewhat of a renaissance in the last decade or so. Various smartphones and tablets are shipping with the technology, and some diehard users swear by it as the best way to take notes on the go. Recently, researchers at the Sensing, Interaction and Perception Lab at ETH Zurich have been working on Flashpen, a high-fidelity pen interface for a wide range of applications.
The fundamental technology behind the pen is simple, with the device using an optical flow sensor harvested from a high-end gaming mouse. This is a device that uses an image sensor to detect the motion of the sensor itself across a surface. Working at an update rate of 8 KHz, it eclipses other devices in the market from manufacturers such as Wacom that typically operate at rates closer to 200Hz. The optical sensor is mounted to a plastic joint that allows the user to hold the pen at a natural angle while keeping the sensor parallel to the writing surface. There’s also a reflective sensor on the pen tip which allows cameras to track its position in space, for use in combination with VR technology.
How many people still have a PS/2 keyboard kicking around in 2020? Admittedly asking such a question of the Hackaday audience is probably cheating (there’s a decent chance one of you will type a comment on one just to prove a point), but even the most pedantic reader has to admit that it’s a long dead standard. So we’re hardly surprised to hear that [Turbaned Engineer] didn’t have one handy when he tried to boot a motherboard so old that he couldn’t access the BIOS with a USB keyboard.
But rather than waiting for an adapter to show up in the mail, he decided to rig up an Arduino Nano to mimic a PS/2 keyboard just long enough for him to navigate the system configuration. Since that basically meant he only needed the arrow keys and Enter, he was able to rig up a handful of momentary buttons to serve as input. We wouldn’t recommend typing out your memoirs with such a spartan board, but it’s certainly good enough to juggle around the order of boot devices.
The fun didn’t stop there, though. [Turbaned Engineer] also had to clean some corrosion and fix a blown resistor on a bank of RAM to drag this old soldier over the finish line. He didn’t have a case handy, so he made a free-form one using the polycarbonate packaging that ICs ship in. The final machine isn’t exactly a sleeper, but it’s good enough to play Super Mario Bros. 3 on the TV.
At the end of the day, the minimal input device [Turbaned Engineer] put together isn’t so far removed from other homebrew keyboards we’ve seen recently. It seems that QMK even has some basic support for the PS/2 interface. Not that it would come up very often, but a “retro” mode might be an interesting addition to your next custom keyboard build.
The ThinkPad is generally considered the unofficial laptop of hackerdom, so it’s no surprise that we see plenty of projects focused on repairing and modifying these reliable workhorses. But while we usually see folks working on relatively modern incarnations of this iconic line of computers, this project by [Frank Adams] and [Brian Chan] shows that the hacker’s love affair with the ThinkPad stretches back farther than many might realize.
As explained on the project’s Hackaday.io page, the duo have produced an open hardware board that will allow you to take the keyboard and trackpoint from a late ’90s ThinkPad 380ED and use it as a standard USB input device on a modern computer. According to [Frank], the keyboards on these machines are notable for having full-size keys rather than the “chicklet” boards that are so common today.
Now you may be wondering why this is significant. After all, we’ve seen plenty of projects that hook up an old keyboard to a USB-equipped microcontroller to get them speaking the lingua franca. Well, the trick here is that the trackpoint on these older ThinkPads actually required additional circuitry on the motherboard to function. The keyboard features three separate FPC connections for the matrix, the trackpoint buttons, and the analog strain gauges in the trackpoint itself.
After a considerable amount of reverse engineering, [Frank] and [Brian] have developed a board that uses the Teensy 3.2 to turn this plethora of pins into something useful. In the video after the break, you can see the new composite USB device working perfectly on a modern Windows computer.
You’ve (probably) got four limbs, so why are you only using half of them when you’re working on the computer? Just because your toes don’t have the dexterity to type (again, probably) doesn’t mean your feet should get to just sit there doing nothing all day. In a recent project, [MacCraiger] shows you just how easy it can be to put some functionality under foot by building a pair of media control stomp switches.
If the devices pictured above look a lot like guitar effects, that’s because they share a lot of parts. [MacCraiger] used the same sort of switch and aluminum case that you might see on a pedal board, as he figured they’d be better suited to a lifetime of being stepped on than something he 3D printed.
Up on the desk, and this time in a printed case, is the Arduino Leonardo that they connect to. The wiring for this project is very straightforward, with the switches connected directly to the GPIO pins. From there, the Arduino firmware emulates a USB Human Interface Device and fires off the appropriate media control keystrokes to skip to the next track or pause playback depending on which switch has been engaged.
This hardware isn’t exactly breaking any new ground here, but we did like how [MacCraiger] used standard 3.5 mm audio cable and the associated jacks to connect everything up. It’s obviously on-theme for what’s essentially a music project, but more importantly, gives the whole thing a very professional look. Definitely a tip to mentally file away for the future.
As [Jan Derogee] explains in the faux-retro video after the break, drawing on classic 8-bit computers was something of a pain. The rudimentary light pens and joysticks of the 1980s allowed for free-form input, but were clumsy and awkward to use. Which is why he set out to create an ideal drawing device for the C64 using modern electronics. For the sake of completion, he also gave it a USB HID mode so it would work on somewhat more modern computers.
His device, which he’s calling the Commo Pad, looks like it could have been transported here directly from the 1980s, but it’s built from entirely new hardware. The case is actually made of wood that [Jan] sanded and painted to give it that chunky plastic aesthetic that we all know and love, and the retro artwork on the touch panel really goes a long way to sell the vintage vibe.
Speaking of which, the touch panel is perhaps the most interesting component of the entire build. It’s actually a resistive panel that was meant for mounting to an LCD that [Jan] has connected to an Arduino. All he had to do was provide a stable frame for it and print out some art work to slide in behind it.
The Arduino and associated electronics allow the Commo Pad to be picked up by the C64 as either a joystick or mouse, which means it doesn’t need any custom software on the computer side to function. Similarly, it can also mimic a USB mouse if you want to plug it into something made a bit later than 1982. Should you be so inclined to make it wireless, the addition of a Bluetooth seems like it would be relatively trivial.
After verifying that the knob worked for volume control on his computer, [Tysonpower] decided to try and pull the firmware from the device’s STM32 microcontroller. Unfortunately, this is where things got tricky. It turned out the chip had Code Protection enabled, so when it was wired up to a programmer and put into DFU mode, the firmware got wiped. Oops.
That left [Tysonpower] with no choice but to write a new firmware from scratch, which naturally required reverse engineering the device’s hardware. Step one was reading up on STM32 development and getting the toolchain working, which paved the way to getting the knob’s LED to blink. A couple more hours worth of work and some multimeter poking later, and he was able to read the knob’s movement. He describes getting USB HID working as a nightmare due to lack of documentation, but eventually he got that sorted out as well.
This multi-touch touch panel built by [thiagesh D] might look like it came from the retro-futuristic worlds of Blade Runner or Alien, but thanks to a detailed build video and a fairly short list of required parts, it could be your next weekend project.
The build starts with a sheet of acrylic, which has a grid pattern etched into it using nothing more exotic than a knife and a ruler. Though if you do have access to some kind of CNC router, this would be a perfect time to break it out. Bare wires are then laid inside the grooves, secured with a healthy application of CA glue, and soldered together to make one large conductive array. This is attached to a capacitive sensor module so it’ll fire off whenever somebody puts a finger on the plastic.
With RGB LED strips added to the edges, you could actually stop here and have yourself a very cool looking illuminated touch sensitive panel. But ultimately, it would just be a glorified button. There’s plenty of interesting applications for such a gadget, but it’s not going to be terribly useful attached to your computer.
To turn this into a viable input device, [thiagesh D] is using a Raspberry Pi and its camera module to track the number and position of fingertips from the other side of the acrylic with Python and OpenCV. His code will even pick up on specific gestures, like a three finger drag which changes the colors of the LEDs accordingly in the video below. The camera’s field of view unfortunately means the box the panel gets mounted to has to be fairly deep, but if recessed into the surface of a desk, we think it could look incredible.