Modern handheld gaming hardware is great. The units are ergonomic powerhouses, yet many of us do all our portable gaming on a painfully rectangular smartphone. Their primary method of interaction is the index finger or thumbs, not a D-pad and buttons. Shoulder triggers have only existed on a few phones. Bluetooth gaming pads are affordable but they are either bulky or you have to find another way to hold your phone. Detachable shoulder buttons are a perfect compromise since they can fit in a coin purse and they’re cheap because you can make your own.
[ASCAS] explains how his levers work to translate a physical lever press into a capacitive touch response. The basic premise is that the contact point is always touching the screen, but until you pull the lever, which is covered in aluminum tape, the screen won’t sense anything there. It’s pretty clever, and the whole kit can be built with consumables usually stocked in hardware stores and hacker basements and it should work on any capacitive touch screen.
When he was but a wee hacker, [WhiskeyDrinker] loved to play with the big console stereo his grandparents had. The idea of a functional piece of furniture always appealed to him, and he decided that when he grew up and had a place of his own he’d get a similar stereo. Fast forward to the present, and a Craigslist ad for a working Penncrest stereo seemed to be a dream come true. Until it wasn’t.
The final result really does look like some kind of alternate timeline piece of consumer electronics: where chunky physical buttons and touch screens coexisted in perfect harmony. The vintage stereo aficionados will probably cry foul, but let them. [WhiskeyDrinker] did a fantastic job of blending old and new, being respectful to the original hardware and aesthetic where it made sense, and clearing house where only nostalgia had lease.
A HiFiBerry DAC+ Pro is used to get some decent audio out of the Raspberry Pi, and the touch screen interface is provided by Volumio. [WhiskeyDrinker] mentions that it even has a GPIO plugin which he successfully used to handle getting the physical buttons to play nice with their digital counterparts.
Remember the “paperless office”? Neither do we, because despite the hype of end-to-end digital documents, it never really happened. The workplace is still a death-trap for trees, and with good reason: paper is cheap, literally growing on trees, and it’s the quickest and easiest medium for universal communication and collaboration. Trouble is, once you’re done scribbling your notes on a legal pad or designing the Next Big Thing on a napkin, what do you do with it?
If you’re anything like us, the answer to that question is misplacing or destroying the paper before getting a chance to procrastinate transcribing it into some useful digital form. Wouldn’t paper that automatically digitizes what you draw or write on it be so much better? That’s where this low-cost touch-sensitive paper (PDF link) is headed, and it looks like it has a lot of promise. Carnegie-Mellon researchers [Chris Harrison] and [Yang Zhang] have come up with cheap and easy methods of applying conductive elements to sheets of ordinary paper, and importantly, the methods can scale well to the paper mill to take advantage of economies of scale at the point of production. Based on silk-screened conductive paints, the digitizer uses electrical field tomography to locate touches and quantify their pressure through a connected microcontroller. The video below shows a prototype in action.
Current cost is 30 cents a sheet, and if it can be made even cheaper, the potential applications range from interactive educational worksheets to IoT newspapers. And maybe if it gets really cheap, you can make a touch-sensitive paper airplane when you’re done with it.
Curves are a breeze to draw with a stylus instead of joysticks, but it’s still a 2-D plotter and must be treated as such. The Touch-A-Sketch system relies on the toy’s stylus starting in the lower left hand corner, so all masterpieces must begin at (0,0) on the knobs and the touch screen.
The BOM for this project is minimal. A PIC32 collects the input coordinates from the touch screen and sends them to a pair of stepper motors attached to the toy’s knobs. Each motor is driven by a Darlington array that quickly required a homemade heat sink, so there’s even a hack within the hack. The team was unable to source couplers that could deal with the discrepancy between the motor and knob shaft sizes, so they ended up mounting the motors in a small plywood table and attaching them to the stock knobs with Velcro. This worked out for the better, since the Etch A Sketch® screen still has to be reset the old-fashioned way.
We’re slowly moving in the direction where everyone will have a touch screen desk like in the 1982 TRON movie or in the 1987 Star Trek: The Next Generation series with its ubiquitous touchscreen starship controls. [FFcossag] lucked into that future when a local company offered him an industrial 42″ multitouch PC that they were throwing out. A few hacks later and he has us all suitably envious.
Before hacking away though, he had to take care of some magic smoke. The source of this turned out to be yellow goop on the PC’s power supply that had turned conductive across a resistor. Cleaning it fixed the problem.
Moving on to the hacks, he added brightness control by using a potentiometer to control the power to the backlight. Be sure to watch carefully in the video below where he’s attaching a magnet and cord to the potentiometer, and encasing it all in epoxy. At that point, we’re pretty sure we see him spin up a hard drive platter with a sandpaper disk attached to it, forming a bench top disc sander and making us like this hack even more.
He also replaced a small speaker with a larger speaker and amplifier, giving a volume and sound quality difference that’s like night and day. He also added a breakout board with relays for power management, eliminating a seven watt continuous draw when in standby mode.
Be sure to watch the video to the end where he leaves us with a tour of the hacked interior hardware. We like how he’s labeled all his handiwork for any future hacker who might open it up
Anytime you’re having more than a handful of people over to your place for a wild rager or LAN party (or both), you’ll generally need a way to make sure everyone can get their devices on the network. Normally, this would involve either putting your WiFi password into more phones than you can count or yelling your password across a crowded room. Neither of these options suited [NicoHood] and his partner, however, so he came up with another more secure solution to the WiFi-in-a-crowded-room problem.
He calls his project “guestwlan” and it’s set up to run on a Raspberry Pi with a touch screen. When a potential WiFi user approaches the Pi and requests access to the network, the Pi displays a QR code. Within that code is all of the information that the prospective device needs to connect to the network. For those who have already spotted the new security vulnerability that this creates, [NicoHood] has his guest WiFi on a separate local network just to make sure that even if someone nefarious can access the Internet, it would be more difficult for them to do anything damaging to his local network. As it stands, though, it’s a lot more secure than some other WiFi networks we’ve seen.
[NicoHood] also released his software on Git but it has been configured for use with Arch. He says that it would probably work in a Debian environment (which the Raspberry Pi-specific OS is based on) but this is currently untested. Feel free to give it a try and let us know how it goes.
Specifically the strap has electrodes that couple a 50V, 150kHz signal through your finger, to the touchscreen. The touchscreen picks up both your finger’s location through normal capacitive-sensing methods and the background signal that’s transmitted by the “watch”. This background signal is modulated on and off, transmitting your biometric data.
The biometric data itself is the impedance through your wrist from one electrode to another. With multiple electrodes encircling your wrist, they end up with something like a CAT scan of your wrist’s resistance. Apparently this is unique enough to be used as a biometric identifier. (We’re surprised.)