24 Cellphone Buttons Controlled With 6 Microcontroller Pins

June 22, 2011 by Mike Szczys 30 Comments

[J8g8j] has been playing around with an old cellphone. He wanted to control it using a microcontroller but since there’s 24 buttons he wasn’t thrilled about hooking up a couple dozen relays to do the switching. Instead, he managed to control all 24-buttons using just 6-pins of a microcontroller.

The proof-of-concept video that he posted on his site shows the phone responding to an arbitrary string of button presses. [J8g8j] spent the majority of his time reverse engineering how the phone’s keypad is wired. Once he figured out the rows and columns of the key matrix he soldered wires to access each of them. This turns out to be 14 connections. To these, he wired up a set of opto-isolators to handle the switching. These are in turn controlled by a set of three 74HC138A 3-8 bit decoders. what’s left are six input pins that leave plenty of room for him to hook up other items to the Arduino serving as the microcontroller.

If You Don’t Have A Steampunk Smartphone…

June 18, 2011 by Nick Schulze 21 Comments

[Richard] has been working on the concept of “incorporating more feeling into our digital objects”. His design is still just a concept but hopefully someone will take up the idea because we think the results would be amazing. The attention to detail in the design is impressive, the Rotary Mechanical Smartphone as he is calling it contains a generic smartphone maintaining all the features such as the touch screen, but also including a set of interchangeable rotary dials on the back. There is the true rotary dial just like an old phone and a push button dial, for complete integration of the old and new technologies.

Once the design was complete, Richard built himself a proof of concept model to show off his work. The shell was 3D printed and copper plated to get the desired steampunk finish. The rotary dials are made from brass plate and hand finished. [Richard] has put in a lot of effort getting the finish right with electroplating, painting, and sanding. The final results are nothing short of impressive. Check out his site for some very nice photos and build details.

Antenna Cannon For Amateur Radio

June 16, 2011 by Brian Benchoff 32 Comments

As an amateur radio enthusiast, [Andrew] sometimes has to set up impromptu antennas up to 160 meters in length. The easiest way to get these antennas off the ground is to drape them over trees, a feat normally accomplished by lofting fishing line into the air with a slingshot or bow and arrow. [Andrew] thought slings were so last century, so he came up with a spud gun inspired antenna launcher.

The launcher is built out of PVC and launches a foam filled tennis ball that can reel out 150 yards of Spectra line. In a moment of brilliance, [Andrew] decided to add an augmented reality HUD. The display is actually [Andrew]’s phone running an app called Geocam that provides him with a display of elevation and azimuth overlaid on the phone’s camera feed. The results of [Andrew]’s build are fairly impressive. The cannon was able to lob a tennis ball over a 110 foot tree at half the pressure rating of the PVC. The grouping was pretty tight as well, more than sufficient to run a line over a tree.

[Andrew]’s antenna cannon is an awesome piece of work and unlike most french fry cutters, it’s a useful tool. If you’re interested in seeing 160 meter antennas heaved over the tops of trees, amateur radio field day is next ~~month~~ week, June 25th and 26th.

An Even Simpler Smartphone Garage Door Opener

June 15, 2011 by Nick Schulze 39 Comments

We have seen smartphone garage door openers in the past, but [Lou’s] Hack is beautiful in its simplicity. His door opener tackles the problem without using computers, Arduinos, wireless modules or even any smartphone based applications. For this project all that is needed is a Bluetooth headset and a single transistor. The door opener uses the Samsung HM1100 Bluetooth headset, which [Lou] has done significant testing on to show that his creation is quite secure and will not open the door unexpectedly.

When this headset connects to a phone it produces a beep from the earbud, so [Lou] removed the speaker and replaced it with a transistor. Now he can use the voltage spike produced by the amplifier before the beep as his switching signal. By wiring the transistor in parallel with the door button inside his garage he is able to open the door wirelessly by connecting then right away disconnecting from the headset. This setup is apparently perfectly secure as the only way to initially link your phone with the headset is to be inside the garage. Check out the video after the break for build instructions and a demonstration.

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Celebrating The Design Principles Behind Cellphones

June 14, 2011 by Mike Szczys 4 Comments

Want to improve the finished look of your projects? There’s a lot you can learn by looking at the choices made in consumer electronics. [Bill Hammack] explores what is perhaps the most refined electronic device out there, the cell phone. Specifically, he discusses the seven design constraints that face every cellphone maker. They are: compactness versus usability, consumer preference, availability of energy, economic resources and available infrastructure, knowledge of materials, societal needs, and cultural constraints.

Anyone who’s whipped out their hacked-together project in a public space understands cultural constraints. Especially when forgetting your backpack in a public place can put the bomb squad of full alert these days. But aside from the anecdotal issues, [Bill’s] look at now-and-then cellphones really shows off the smart design that we enjoy thanks to the evolutionary process that went into what has become the wristwatch of the 21st century. See what he has to say in the video after the break.

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GPS Without GPS

June 14, 2011 by Brian Benchoff 32 Comments

Open Electronics just released a neat little board that can place you on a map without using GPS.

The board works on the basic principles of a cellphone network – the ‘cell’ network is a series of towers that are placed more or less equidistant to each other. Save for the most desolate parts of the country, a cell tower usually communicates with a phone one or two miles away. Usually, several cell towers can be seen, so the position of a cellphone can be pinpointed to within 200-350 feet. Translating cell towers to latitude and longitude is easily done by querying a Google database that was created for the mobile version of Google Maps.

The board itself is a PIC18 microcontroller and a SIM900 GSM module. The firmware available at Open Electronics is pretty impressive – all communication to the board is handled through SMS and the phone can report it’s location to 8 other phones.

It’s pretty impressive to think the same technology that caught [Kevin Mitnick] is now available to the masses. We’re wondering what Hack a Day readers would use this for, so if you have an idea leave a comment.

IOIO Now Supports Android Open Accessory

June 9, 2011 by Brian Benchoff 9 Comments

After the announcement of the Android Open Accessory ADK, [Ytai] decided he should get the the ADK running on the IOIO Android breakout board.

The first batch of Android ADK boards sold for about $400. While that price has come down considerably, the IOIO is still cheaper and smaller. [Ytai] put the source and all the technical info on his wiki.

Interestingly, this beta build is a little more capable than the Google offering. The IOIO supports the Android Debug Bridge, so it’s able to work with any Android device made since the beginning of time. The IOIO will try to communicate with the device using the Open Accessory standard because of the much better throughput and latency, but will seamlessly fall back to ADB if the device doesn’t support Open Accessory. Open Accessory boards are only comparable with devices running Android 2.3.4 and higher, so it looks like we’ve got a standard breakout board for the $99 Android tablets that fly off the shelves during Christmas.

[Ytai] has gotten a few of his projects on Hack a Day, like his PICMAN prototyping setup and his awesome 2 foot POV globe, so we’re happy to see this very skilled builder finally get his Hack a Day hat trick and enters the ranks of giants like [Sprite_tm]. If you’ve got a great build, send it in and you might be able to join the pantheon of great builders.