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.

Solar Powered Cellphone A True Hack

June 7, 2011 by Mike Szczys 34 Comments

The polished quality of this hack isn’t quite there, but we love the ingenuity and exploration exhibited. [Paulie1982] shows us how to make an old cellphone work with the rays of the sun.

You can see above that he’s added photovoltaic solar cells to the back case of what looks like an old smart phone. He grabbed the cells from two inexpensive solar landscaping lights and inserted them by cutting holes in the case and using black silicone sealant to glue them in place. Each can pump out about 3V and together they get above the 5V threshold that he needs to do some charging. See the build process in the video after the break.

From what we’ve seen there’s zero consideration of current in this hack and that’s what makes us skeptical. Still, we love the idea of trickle charging and we’d love to see some speculation in the comments about how to improve upon this. Surely the additional hardware necessary for proper regulation, etc. could be fit in a custom case cover like the one used for this inductive charger hack.

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GSM-to-Skype Bridge Lets You Lose Those Roaming Fees

May 11, 2011 by Mike Szczys 21 Comments

Here’s the scenario: you’re going to be traveling somewhere and you’ll be charged roaming fees if you use your cellphone. But there is free WiFi available in this place. You can save yourself money by leaving your SIM card at home and using a GSM-to-Skype bridge to take calls on your phone via WiFi.

[Trax] is using a USB GSM modem to take cellphone calls on a PC. He leaves his sim card in this modem so that it can make and receive calls and text messages through your normal telephone number. For some reason, the USB connection only provides control of this modem and doesn’t pass bi-directional audio. To make this happen, he built an audio interface cable using two transformers and a few passive components to connect the modem to the computer’s audio card.

On the software side of things, an application written in Delphi 7 manages the modem, the audio stream, and the Skype application. When a call is incoming it sets up a Skype connection with your handset via the Internet, passing along the caller ID data in the process. If you choose to answer the Skype session the application will pick up the GSM call and you’ll be connected. It works the same way when placing an outgoing call.

This seems easier to manage than a rig that physically pushes a cellphone’s buttons via the Internet.

[Thanks Mure]

Long-range Bluetooth Wardriving Rig

April 15, 2011 by Mike Nathan 56 Comments

bluetooth_wardriving

[Kyle] was digging through a box of junk he had lying around when he came across an old USB Bluetooth dongle. He stopped using it ages ago because he was unsatisfied with the limited range of Bluetooth communications.

He was going to toss it back into the box when an idea struck him – he had always been a fan of WiFi wardriving, why not try doing the same thing with Bluetooth? Obviously the range issue comes into play yet again, so he started searching around for ways to boost his Bluetooth receiver’s range.

He dismantled the dongle and found that the internal antenna was a simple metal strip. He didn’t think there would be any harm in trying to extend the antenna, so he soldered an alligator clip to the wire and connected the CB antenna in his truck. His laptop sprung to life instantly, picking up his phone located about 100 feet away in his house. He took the show on the road and was able to pick up 27 different phones set in discoverable mode while sitting in the parking lot of a fast food chain.

While it does work, we’re pretty sure that the CB antenna isn’t the most ideal extension of the Bluetooth radio. We would love to see what kind of range he would get with a properly tuned antenna.

Keep reading to see a quick demonstration of his improvised long-range Bluetooth antenna.

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