A Clever Solution For Constantly Locking Workstations

March 12, 2013 by Brian Benchoff 57 Comments

ROBOT

[Vasilis] works at CERN, and like any large organization that invented the World Wide Web, they take computer security pretty seriously. One ‘feature’ the IT staff implemented is locking the desktop whenever the screen saver runs. When [Vasilis] is in his office but not at his battlestation, the screen saver invariably runs, locking the desktop, and greatly annoying [Vasilis].

The usual Hackaday solution to this problem would be a complex arrangement of RFID tags, webcams, and hundreds, if not thousands of lines of code. [Vasilis] came up with a much better solution: have the computer ping his phone over Bluetooth. If the phone is detected by the computer, kill the screen saver.

The code is up on Github. It’s not much – just 20 lines of a Bash script – but it’s just enough to prevent the aggravation of typing in a password dozens of times a day.

Wireless Pinball Controller For Tablet Gaming

March 4, 2013 by Mike Szczys 6 Comments

wireless-pinball-controller

This wooden box is a wireless pinball controller and tablet stand. The idea is to set it on a workbench to give you some of the thrill of standing and playing the real thing. [Jeff] has been rather addicted to playing a pinball app on Android lately, and started the journey because he needed a way to give his thumbs some relief.

An Arduino monitors buttons on either side of this wooden controller. [Jeff] is new to working with hardware (he’s a Linux Kernel developer by trade) and was immediately struck with button debouncing issues. Rather than handle this in software (we’ve got a super-messy thread on that issue with our favorite at the bottom) he chose a hardware solution by building an SR latch out of two NAND gates.

With the inputs sorted out he added a BlueSMiRF board to the project which allowed him to connect a Nexus 7 tablet via Bluetooth. At this point he ran into some problems getting the device to respond to his control as if it were an external keyboard. His stop-gap solution was to switch to a Galaxy Tab 10.1 which wasn’t throwing cryptic errors. Hopefully he’ll fix this in the next iteration which will also include adding a plunger to launch the pinball, a part which just arrived in the mail as he was writing up this success.

We’ve embedded his quick demo video after the break.

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Beginner’s Android/Arduino Example Shows The Power Of App Inventor

February 15, 2013 by Mike Szczys 20 Comments

This is a simple project. It uses an Android device to switch an LED driven by the Arduino. Connectivity is provided by the Bluetooth module inserted in the breadboard. But one look at the UI on the Android device and you might think this is anything but simple. The truth is that [Kerimil] didn’t spend forever learning Java and programming the app. Instead he’s showing off the power of App Inventor to get your Android controls up and running fast.

Check out the third button down; when was the last time you added voice commands to your project? It’s worth clicking through to see just how simple that portion was. App Inventor — a Google cast-out that is now maintained by MIT — is a graphical tool that unlocks the power of an Android handset to those with the most basic of programming understanding. For instance, the voice controls shown off after the break are provided by a single bracket which uses conditional statements to ‘listen’ for the words on, off, and blink. You’ll find the voice recognition diagram after the break as well.

You could try to go completely graphical with this project. There’s the option of programming the Arduino side of the project in a similar way.

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This Man Will Take Your Picture While Macing You

January 29, 2013 by Brian Benchoff 40 Comments

pepper

Odds are you don’t have a photographic memory, so if you ever have to mace someone, you probably won’t remember exactly what your attacker looks like. Compound that with talking to the police and looking at a few dozen mug shots, and it’s highly unlikely you’ll ever be able to identify the person you maced. This was the problem [John], [Cordelia], and [Adrian] chose to solve for [Bruce Land]’s microcontroller course at Cornell this semester.

The device they created, PepGuard, adds a microcontroller and a serial JPEG camera to a canister of pepper spray. When the button on top is pressed, the microcontroller flashes a LED, takes a picture with a camera, and sends that picture to a phone over a Bluetooth connection.

PepGuard is always connected to the user’s phone via Bluetooth, and this allows for some interesting possibilities. With their Android app, the team can set up the phone to call emergency services when the device is activated.

You can check out the demo of the device after the break, or read the team’s report here.

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Adding A Bluetooth Terminal To Your Router

January 22, 2013 by Mike Szczys 14 Comments

bluetooth-router-terminal

This image shows an Android tablet monitoring the terminal of a router via Bluetooth. It makes it a snap to tweak your router from a multitude of devices as long as you’re within range (usually BT works up to about 30 feet or so). The only part that [Yohanes] needed to pull off the hack was a Bluetooth module which he picked up for a few dollars.

All routers will have serial connections somewhere on the board. His model (Asus RT-N16) even had the GND, RX, TX, and VCC pads labeled. He soldered a SIL pin socket to the port which accepts the pin header from the Bluetooth module. Before plugging that in he had to issue a few commands to the device to get it using the same baud rate and settings as the router’s serial port. With that taken care of he can now wirelessly monitor and control the device via the serial terminal.

The one issue which he did encounter is that the module is slower to boot than the router. This means that at power-up you will not see anything on the terminal until the router has already started to load the Linux kernel. If you don’t plan on doing any bootloader hacks this shouldn’t make any difference.

Polaroid Catcher Make Print Screen Do What It Says

January 16, 2013 by Mike Szczys 6 Comments

polaroidcacher_2

As part of their coursework at ITP New York a group of students developed the Polaroid Catcher. It’s a way to make your digital experiences more permanent. When you have something on-screen that you’d like to keep as a memory you can print the screen on this old Polaroid camera. Of course you’re not going to get the chemical-filled container you may remember from ages past. But we thing you’d agree the nostalgic camera makes a nice enclosure for a modern image printer.

The workings of the system are shown off quite well in the clip after the break. But we’re always interested in the particulars of how they pulled it off. The system uses a Google Chrome extension to capture what is being displayed in the browser. Before the image is sent to the printer the user has the opportunity to frame up the subject of the photo. Once decided, the image is pushed to a Bluetooth photo printer using some scripts written by the team.

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A Bluetooth Trackpad From A Resistive Touchscreen

January 14, 2013 by Brian Benchoff 23 Comments

touch

If you’ve checked out your favorite online retailer of absurdly inexpensive Chinese electronics, you’ll find a whole bunch of replacement parts. Phone parts are especially common, with high-resolution LCDs available for just a few dollars. There are also a few touchscreen kits – resistive touchscreen digitizers that can easily be read with a microcontroller. [Vinod] got his hands on one of these touchscreen digitizers, and with the help of an 8-pin micocontroller turned it into a Bluetooth trackpad.

The clear plastic touchpad is a relatively simple device. By reading a pair of analog values, it’s easy to find the coordinates of a finger or stylus on the touchpad. [Vinod] programmed an ATtiny13 to read these values and turn them in to x y coordinates, but he needed something useful to do with this data.

By connecting a small bluetooth module to his microcontroller, [Vinod] could send these coordinates to his computer. The result is a homebrew touchpad, able to move a cursor around, left and right click, and emulate a scroll wheel.

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