Instructables user [trumpkin] recently built an all-hardware based keypad lock for a contest he was entering, and we thought it was pretty neat. The lock uses mostly NAND gates and 555 timers to get the job done, which makes it a nice alternative to similar software-based projects we have seen in the past.

The lock has 6 keys on the keypad, which is connected to the main logic board. The keycode is set using a series of headers at the bottom of the board, and you get 10 chances to enter the proper code before the board locks up completely. If this occurs, a “manual” reset via a button built into the main board is required before any more attempts can be made.

As you can see in the video below, the lock works quite well, but suffers from one shortcoming. Any permutation of the key code can be used to deactivate the lock, which is something [trumpkin] says he would like to improve in the future.

If you are looking for some more security-related reading, be sure to check out these other hacks we have featured in the past.

If you’re on the fence about 3D TV and related technologies [Anton B.] might be able to help you decide. No, he’s not going to shove pamphlets in your face and explain why its the wave of the future. Rather, by showing the hack-ability (its a word) of 3D shutter glasses. A simple bridge of wire across specific contacts can ‘trick’ the glasses into only displaying only the left or right picture.

Wouldn’t that make it just a regular 2D TV again? Yes, that’s the beauty of it. Person A could be watching a completely separate movie pr0n than person B, but all on the same TV. Or two people could be playing a video game, without dividing the screen in half. The only problem is the current lack of software that can interlace movies/games, who’s up for writing some C++ this weekend?

It’s inevitable. You knew it, we knew it, and while this is being posted on April 1st; its no joke. [johndavid400's] Core3Duino. As we mentioned before, with the additional Arduinos you have now 3 separate processors, allowing 24digital IO, 18 PWM, 18 analog inputs, and more.

Now to keep flamers at bay (calm down), we’ve combined this post with the introduction of xDuino. Yet another attempt at porting Arduino to separate hardware platforms. For the price of a Duemilanove you can have 5 serial, 48 IO, 18 analog, 68Kbytes of Ram and more!

[Thanks Kamil]

Often, hardware designers include nonfunctional additions into designs to make them feel more personal. Commonly known as easter eggs, these additions can often go unnoticed by the public for years. While taking apart an Atari San Francisco Rush: The Rock sound board, reader [Jason] noticed a hidden message on the PCB (see above). Other more recent hardware easter eggs include the inside of the Zune HD, which has the inscription “For our Princess” to commemorate a development team member who passed away, or the Amiga 1000 which features the signatures of the design team on the inside if the case (Pictures after the break).

What we want from you: We want to see the best HARDWARE easter eggs you have found or seen. Leave us a comment with a video, picture, or article that explains what you found, and possibly the background story behind it. Anyone can google easter eggs, and we all know about the easter eggs all over DVDs, video games, etc, but we prefer the kind you find when you are busy voiding your hardwares warranty.

Edit: good catch, that was the Amiga 1000 not an Atari 1000. Thanks to all the commentors.

Atari 1000 case [via OldComputers]

Zune HD internals [via iFixit]

With another hacker conference looming in front of us, it’s time to start thinking about hardware security. Hacker conventions have the most hostile network you’ll ever encounter. [Security4all] points out that 25C3 already has an extensive page on securing your hardware. It starts from the ground up with physical security, BIOS passwords, and locking down bootloaders. There’s a section on securing your actual OS and session. Finally, they cover network usage. It mentions using SSH for dynamic forwarding, which we feel is a skill everyone should have. We’ve used it not just for security, but for bypassing brainless bandwidth restrictions too. There’s also the more trick transparent version. Every piece of data you bring with you, you risk losing, so they actually recommend just wiping your iPhone and other devices before attending. It’s important to remember that it’s not just your own data at risk, but everyone/thing you communicate with as well.

Technology Review turns the spotlight on the open source hardware movement. Open source hardware is hardly a new concept, but lately it’s been getting a lot more attention, with the help of magazines like MAKE and websites like Instructables. Chumby, a company that sells a modifiable cube with a screen, embedded computer, and a Wi-Fi connection, designed their product to be easily hackable. The openness of the product caused a community heavily invested in the product’s development to be created. The growth of such communities has also sparked interest from corporations such as Nokia, which is collaborating with MIT on open source video decoders. They recognized that opening up would cause development time to be reduced and provide greater flexibility, allowing them to allocate resources to other areas, including marketing and brand development. [Jamey Hicks], director of the Nokia Research Center in Cambridge, believes that the open source movement can even complement closed designs, as long as it’s handled appropriately. With greater access to sophisticated software tools and resources, the barriers to entry keep falling away, and it’s much easier for the world to discover the joys of tinkering and hacking.

[photo: Andreas Pizsa]

For people who miss the golden age of Atari music, you can recreate the magic of 8 bit music with the -hard plAYer-. [Tolaemon] put a lot of thought and work into this hardware player. From the AY-38912 programmable sound generator, which used to be in old computers like the Atari or Colour Genie, to working with the YM file format, each piece is put together with the utmost care. [Tolaemon] also provides his design, firmware(ZIP), and parts list so that you can make your own hardware player.

[via Matrixsynth]

The latest generation of Arduino hardware has been released. The Arduino Duemilanove (2009 in Italian) has the same form factor as previous generations. The specs are essentially identical to the Diecimila, but there have been a few changes to the hardware. The power source is no longer chosen using a jumper. A MOSFET and dual OPAMP have been added to the board to automatically selected between USB power and the external plug. Automatic hardware resets are optional now. Next to the USB port are two solder pads labeled RESET-EN. Cut the trace between them to kill the reset. If you ever want it back, just bridge the pads. The hardware was updated to correspond with the release of Arduino cofounder [Massimo Banzi]‘s new book.

To replace the old door strike with our new electric unit, we had to align it with the old one. Once it was set, we traced around the mounting plate with a pen and got to work. We grabbed a 3/8 inch bit and drilled out the width and depth of the hole to match the body of the strike. Then we cleaned up things a bit with a wood chisel until the hole was just big enough. The strike requires 12 volts to release, so we had to feed some wire to it. We dug up a fairly long drill bit and drilled through the wall and into the strike mounting hole.

The strike wiring is low voltage, so the wire doesn’t have to be anything special. We used some 18 gauge speaker wire – it’s cheap and we already had it in our parts bin. Pulling the wire is pretty easy. Just feed the wire through and grab the end with a pair of needle nose pliers. Since we had 50 feet of wire to work with, we pulled the wire over to our bench and did a quick soldering job to the strike leads. Once the connections were solid, we insulated them with electric tape. There’s no polarity to worry about, so just get things connected and ready to rock.

The strike has a thick mounting flange, so we had to remove some wood from the surface of the door frame. After some quality time with a hammer, flat headed screw driver, and a wood chisel, we managed to cut a decent mounting slot. Once the wiring was insulated, we pulled in the slack and mounted the strike with a pair of three inch screws.

We’ll be wall mounting the keypad, so we picked up an “old-work” two gang electrical box and a two gang blank wall plate. Mounting the box is pretty easy, but we’ll walk you through it.

To make the bezel, we laid out the buttons in CorelDraw and scaled up each button by a few percent. Once the size was correct, we rounded off the corners to match the buttons better.

After a few test fits made by cutting paper, we put the wall plate into our ever handy laser cutter. We realize that most of you don’t have one of these awesome machines – you can create your own with some careful drilling and dremel work (it might be easier to bribe the local sign shop with some beer). If you do have it laser cut, make sure you get a nylon wall plate and not a PVC plate. The fumes from burning PVC are toxic and air filters will not neutralize them.

When we test fit the new bezel, we found that the flex at the base of each button was impeded. It’s hard to see here, but the wall plate is only about 1/32 of an inch thick. Since it’s so thin, the buttons stick out too far.

To solve both problems, we created a sub-bezel. We used the same laser template, but expanded each hole a bit further. The 1/8 inch acrylic provided perfect depth for the buttons and the larger holes in the sub-bezel provide an area for the buttons to flex.

“Old-work” boxes are designed to be installed into existing drywall. You just have to cut a hole for the box and when the screws are tightened, these tabs will flip up to grip the inside of the wall.

Once the hole’s cut, just insert the box and check the fit. Don’t tighten the screws just yet – we’ll be pulling it back out for a quick mod. Since we’re mounting all the hardware on the other side of the wall, we drilled a hole into the workshop side to run the keypad wiring.

It just happens that Spark Fun’s PC Board is the same width as the 2 gang box. In order to fit the bezel flush, we need to trim back the edge of the box.

You can use your favorite tool, but we grabbed our rotary tool and a small drum sanding bit. Then we ground the edge of the box down to allow for approximately two times the thickness of the keypad PC board. (You might want to adjust this depending on your bezel design.)

The final fit is just about perfect. The edges of the drywall keep the board from shifting while the box supports the board from behind.

Now that the bezels are ready to go, mark your wiring so you can identify it post install. We used some colored electrical tape and noted the connections. Since we used Cat-5, you could easily use RJ-45 connectors to add some modularity. We didn’t need it, so we just pulled the wires through to the workshop side.

To finish up the key pad, we installed the PC board, the keypad, the acrylic sub-bezel, and finally the keypad. Everything actually floats under the keypad. The design has worked perfectly for the past few months – with one exception. One visitor pushed too hard and popped the PC board back into the wall box. If needed, you can add a support strut of some kind behind the PC board.

To create a permanent board for the keypad, we laid everything out in Eagle. Since we wanted to try out some interesting etching ideas, we used extra wide traces and expanded the pads to provide plenty of copper.

After making the keypad bezel, we wanted to try some new tricks with the laser cutter. We coated some copper clad PC Boards with spray paint and let it harden for a few days.

To We exported the design from eagle and sent it to the Epilog via CorelDraw. In order to remove all of the paint, we had to run the etching jo
b twice on the laser. Here, the laser is mid way through the second run.

Even after two jobs, a fine residue was still on the copper. Lightly scrubbing the board with acetone (nail polish remover) removed the left over residue. The traces remained intact and the copper was bared for the etching solution.

Radio Shack doesn’t bother to carry ferric chloride anymore, but we wanted local chemicals. We picked up some muriatic acid (hydrochloric acid), hydrogen peroxide, a cereal container air pump, bubble block, and some hose. The acid is readily available at the hardware store. We suggest finding the smaller container – it’s the perfect amount for a one time fill.

Etching the board is the usual show. The bubbles help agitate the solution around the copper and speed up the process.

The finished etch came out pretty decent, if slightly over-etched. Holding the board up to a light is an easy way to check for top/bottom layer alignment. The board was slightly over-etched, but after spending a couple of weeks mucking around with the process, we decided that it was time to get on with it already.

To drill the board, we used a #59 tungsten carbide drill bit. Instead of a drill press, we manually ran our CNC mini mill to drill the board. We only broke one bit and that was when we fat-fingered a direction key.

One more quick check and the board looks perfect. The milling machine made it easy to keep the holes in line for the build.

Finishing the build is pretty easy (the red wire going over the board was a quick design fix). We added jumpers for all of the Arduino connections and soldered the Cat-5 from the keypad directly to the new board. We won’t bore you with step by step soldering pics. If you prototyped the circuit, you should be intimately familiar with the thing by now. If you need some help soldering, be sure to check out our introduction to soldering.

The bezel’s built, the PC Board etched, the circuit soldered, and the keypad’s installed. The only thing left to do is enjoy the new keypad… or develop more code and teach it some new tricks.

We promised to explain the code a bit, so we’ll give you a quick walk through. The meffect keypad code (available here) was written to simplify the keypad routines for the project. The first several lines initialize the various variables we’ll need to make things work. We added comments regarding pin assignment to help simplify wiring and help people change things around as needed.

The code to drive the digital potentiometer comes directly from this tutorial.

The setup() function is run one time when the controller is powered on or reset. Variables are set and i/o pins are set to their initial states as needed.

The loop() function is the never ending loop where the controller will perform a few tasks. The main order of business is to read the button states for input. Second, the potentiometers are set and each LED is lit temporarily, based on the values in the matrix defined for each LED state. If no action is detected, then the values are set by an effect function. However, if an action is detected, the effect is halted and the button color is set based on the number of inputs keyed in. Next, the loop counts all the button presses that are detected. If the lock exceeds the defined number (in this case, 20) then the pad glows red, state is reset and it locks the user out for about 30 seconds. The final test is the actual lock code. If the keypad state matches the predefined code, then the pad glows green and the door lock is opened for about 5 to 10 seconds.

The code is pretty simple, but the framework is there to produce a more secure lock. The easiest way to up your security would be to create a rolling fade effect and possibly blip the LED color when a key press is detected. Probably the coolest feature of the lock is that you can program it to behave and lock in any way you want.

[via PhotoBasement]

harddisko is a collection of defective hard drives from various manufacturers, repair shops, and institutions. The drives are all wired to separate power circuits. As each one powers up, it runs its own unique sounding self test.

Lastly, is the BeggingBot. Using multiple floppy drives and hard drives it performs music. It then asks for donations via the CD tray.

Justin Wickett was looking for a way to control his room lights via his cellphone. By using Bob Paauwe’s iLink INSTEON software and Twitter, he was able to control basic functions. Now he can SMS text like “bedroom lights off” and the software does his bidding. Of course, in the time it takes to send and process this request you could just as easily walk over and shut of the lights. We’re sure he’s planning more features than just that.

Adafruit Industries is selling an interesting device called the Botanicalls Twitter kit. It will post directly to Twitter when your plant is in need of water. Using a moisture sensor and built in Ethernet port it just requires some basic soldering to get started.

Pictured above is Ninja Networks’ Shoutwall from Defcon (photo: pinguino). It receives and displays direct SMS messages and Twitter updates. It also does reverse number lookups on Dodgeball to get user icons. An Ericsson T39m with a data cable is used because it provides an easy SMS interface. Take it to a party and your service provider is sure to wonder how you managed to receive 4000 inbound txt messages in one weekend.

curl --basic --user "$user:$pass" --data-ascii
"status=testing123" http://twitter.com/statuses/update.json