Secret Keyboard Stash

Hide in plain sight is an old axiom, and one that [Kipkay] took to heart. His sneaky keyboard hack takes the little-used numeric keyboard and converts it to a handy (and secret) hiding hole for small objects you want to keep away from prying eyes.

You might have to adapt the hack to your specific model, but [Kipkay] cuts out the membrane keyboard, secures the numeric keypad keys with hot glue, and then cuts it out with a Dremel. Some cardboard makes the compartment and once the fake keypad is in place, no one is the wiser.

As you can see in the clip after the break, the compartment isn’t very big. You aren’t going to hide your phone inside, but it is just the right size for some emergency cash, a credit card, or maybe an SD card or two.

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Controlling Quadcopters With Wireless Mouse Dongles

Last week we gave away a few Crazyflie 2.0 quadcopters to some cool Hackaday Prize entries. This quadcopter ships with the intention of being controlled by your smartphone. But it can also be controlled by a PC with USB dongle and an nRF24LU1+ SOC. [ajlitt] didn’t figure out he wanted the USB dongle (the Crazyradio) that can control this quad until after he used his gift code to claim his Crazyflie quad. No matter; the dongles for Logitech wireless keyboards and mice use the same radio as the Crazyflie and can be modded to make this quad fly.

The board inside the Logitech unifying receiver is a simple affair, with some pads for the USB connector, a crystal, the nRF24LU1+ radio module, and a few passives. To get this radio chip working with his computer, [ajlitt] simply needed to break out the SPI pins and wire everything to a Bus Pirate.

Getting the Crazyradio firmware onto this proved to be a little harder than soldering some magnet wire onto a few pins. The chip was first flashed without a bootloader, a full image with the bootloader was found, after wrangling a single byte into place, [ajlitt] had a working Crazyflie radio made from a wireless mouse dongle. The range isn’t great  – only 30 feet or so, or about as far as you would expect a wireless mouse to work. Excellent work, even if [ajlitt] is temporarily without a mouse.

The Crazyflie 2.0 is available from the Hackaday Store, along with the add-ons if you don’t want to hack your own.

Stenography (Yes, with Arduinos)

What’s the fastest keyboard? Few subjects are as divisive in the geek community. Clicky or squishy? QWERTY or Dvorak? Old-school IBM or Microsoft Natural? The answer: none of the above.

danger-court-reporter-tyingThe fastest normal-keyboard typists (Dvorak or Qwerty) can get around 220 words per minute (wpm) in bursts. That sounds fast, and it’s a lot faster than we type, but that’s still below the minimum speed allowable for certified court reporters or closed captioners. The fastest court reporters clock in around 350 to 375 wpm for testimony. But they do this by cheating — using a stenotype machine. We’ll talk more about stenography in a minute, but first a hack.

The Hack

[Kevin Nygaard] bought a used Stentura 200 stenotype machine off Ebay and it wasn’t working right, so naturally he opened it up to see if he could fix it. A normal stenotype operates stand-alone and prints out on paper tape, but many can also be connected to an external computer. [Kevin]’s machine had a serial output board installed, but it wasn’t outputting serial, so naturally he opened it up to see if he could fix it. In the end, he bypassed the serial output by soldering on an Arduino and writing a few lines of code.

shot0001The serial interface board in [Kevin]’s machine was basically a set of switches that made contact with the keys as they get pressed, and a few shift registers to read the state of these switches out over a serial connection. [Kevin] tapped into this line, read the switch state out into his Arduino, and then transmitted the correct characters to his computer via the Arduino’s serial over USB. (Video demo) As hardware types like to say, the rest is a simple matter of software.

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Disassembled Mouse Keeps Track Of Gas Meter

After building devices that can read his home’s electricity usage, [Dave] set out to build something that could measure the other energy source to his house: his gas line. Rather than tapping into the line and measuring the gas directly, his (much safer) method was to simply monitor the gas meter itself.

The major hurdle that [Dave] had to jump was dealing with an ancient meter with absolutely no modern electronics like some other meters have that make this job a little easier. The meter has “1985” stamped on it which might be the manufacturing date, but for this meter even assuming that it’s that new might be too generous. In any event, the only option was to build something that could physically watch the spinning dial. To accomplish this, [Dave] used the sensor from an optical mouse.

The sensor is surrounded by LEDs which illuminate the dial. When the dial passes a certain point, the sensor alerts an Arduino that one revolution has occurred. Once the Arduino has this information, the rest is a piece of cake. [Dave] used KiCad to design the PCB and also had access to a laser cutter for the enclosure. It’s a great piece of modern technology that helps integrate old analog technology into the modern world. This wasn’t [Dave]’s first energy monitoring system either; be sure to check out his electricity meter that we featured a few years ago.

BeagleBones And Teensies Become KVMs

[pmf], like most of us, I’m sure, spends most of his days on a computer. He also has a smartphone he keeps at his side, but over the years he’s grown accustomed to typing on a real keyboard. He came up with the idea of making a USB switch that would allow his keyboard to control either his computer or his phone, and hit upon a really neat way of doing it. He’s using a BeagleBone Black and a Teensy to switch his keyboard between his computer and his phone with just a press of a button.

This homebrew smart KVM uses a BeagleBone Black for most of the heavy lifting. A keyboard and mouse is connected to the USB host port of the BeagleBone, and the main computer is connected to the device port. The BeagleBone is set up to pass through the USB keyboard and mouse to the computer with the help of what Linux calls a ‘gadget’ driver. This required an update to the Linux 4.0 kernel.

With the BeagleBone capable of being a USB pass through device, the next challenge was sending keypresses to another USB device. For this, a Teensy 2.0 was connected to the UART of the BeagleBone. According to [pmf], this is one of the few examples of the Teensy serving as a composite USB device – sending both keyboard and mouse info.

There are a few neat features for [pmf]’s build: the keyboard and mouse don’t disconnect when switching, and thanks to a slight modification of the USB OTG adapter, this will also charge a phone as well as allow for the use of a keyboard. Because the BeagleBone Black has more than one UART this build can also switch keyboards and mice between more than two computers. For those of us who invest heavily in keyboards, it’s a godsend.

Embed with Elliot: I2C Bus Scanning

A lot of great ICs use I2C to communicate, but debugging a non-working I2C setup can be opaque, especially if you’re just getting started with the protocol/bus. An I2C bus scanner can be a helpful first step in debugging an I2C system. Are all the devices that I think should be present actually there and responding? Do they all work at the bus speed that I’m trying to run? If you’ve got an Arduino or Bus Pirate sitting around, you’re only seconds away from scanning your I2C bus, and answering these questions.

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Remove Security Issues From Untrusted USB Connections

USB has become pretty “universal” nowadays, handling everything from high-speed data transfer to charging phones. There are even USB-powered lava lamps. This ubiquity doesn’t come without some costs, though. There have been many attacks on smartphones and computers which exploit the fact that USB is found pretty much everywhere, and if you want to avoid these attacks you can either give up using USB or do what [Jason] did and block the data lines on the USB port.

USB typically uses four wires: two for power and two for data. If you simply disconnect the data lines, though, the peripheral can’t negotiate with the host for more power and will limp along at 0.5 watts. However, [Jason] discovered that this negotiation takes place at a much lower data rate than normal data transfer, and was able to put a type of filter in between the host and the peripheral. The filter allows the low-frequency data transfer pass through but when a high-frequency data transfer occurs the filter blocks the communication.

[Jason] now has a device that can allow his peripherals to charge at the increased rate without having to worry about untrusted USB ports (at an airport or coffee shop, for example). This simple device could stop things like BadUSB from doing their dirty work, although whether or not it could stop something this nasty is still up in the air.