Archive for February, 2010

Cellphone controlled door locks

Wednesday, February 24th, 2010

[Tom Lee] and his colleagues of Sunlight Labs just moved to a new office. The doors are setup like a security checkpoint with electronic strikes and buttons on the inside to allow entry. The button simply completes a low-voltage circuit, activating the strike which made it quite easy to patch into. They build an interface board with a small relay to complete that circuit. As we’ve seen before, Linksys routers have plenty of extra room in the case so there was no problem housing the new circuit in this tiny network device. Now [Nicko] and his friends can use a custom app to input an access code or to verify a device ID from a cell phone and gain entry. The door still has keyed locks in case of a power outage. In fact, the only change made to the system was the addition of two wires to the “door release” button as seen above. See the one-touch device ID authentication in the video after the break.

This hack is similar to the GSM door entry from last year. In this case, the phones are communicating with the door via web interface and not the GSM network.

via Hackaday, Sunlight Labs

Serial communication with cell phones

Wednesday, February 24th, 2010


Will O’Brien at has been doing some cellphone integration work. He recently picked up some Motorola c168i cellphones from eBay. It turns out there is a serial port that uses TTL communication with a standard head-phone jack as an interface. [Will] soldered up a connector and used a USB to FTDI cable to interface with the phone. To his surprise he was able to read off the stored text messages even though they were PIN protected in the phone’s operating system. The messages on these units were trivial but this is another example of the importance of clearing your data before discarding your devices.

courtesy of via Hackaday

RFID tracking system

Wednesday, February 24th, 2010

This is a working tracking system using RFID tags built by Nicholas Skinner. The system’s tags operate in the 2.4 GHz band and are used to track either people or assets. The readers are on a mesh network and can triangulate the location of any tag for display on a map. His system is even set up to show the travel history of each tag. [Nicholas] shared every detail in his writeup including some background about available hardware options and how he made his final decisions on what devices to use for the job. His conglomeration of software that ties the whole project together is also available for download.

courtesy: ns-tech

Facial recognition brings online stalking to the real world

Wednesday, February 24th, 2010

What if you could point your cellphone’s camera at someone’s face, and then know that person’s name, schedule, profile, and latest tweets? That’s the promise of Recognizr, an Android app prototype using a 3D model to recognize facial features, find a match on its server, and then superimpose that person’s social networking preferences around his or her face.

Created by Swedish mobile software designers The Astonishing Tribe, it’s astonishing indeed. Problem is, unless everyone opts into this service, it won’t be particularly useful. However, if it were ubiquitous, imagine how easy it would be to act like you’re using your cellphone, but actually be finding out that person’s name standing in front of you — while you snoop around her Facebook profile.

Finally, Facebook stalking finds its way to meatspace! On a smaller scale, this could be useful at, say, a trade show or a party. Electronic nametags would be lots of fun, if everyone would submit to them.

The Astonishing Tribe, via Technology Review

Developing for iPhone serial communications

Thursday, February 18th, 2010

Apple has not made it easy to let the iphone communicate with external devices. Basically, you need a jailbroken phone to do anything. This post covers the current state of serial communication on the iphone.

A succesful example of making an application that uses the serialport on the iphone is xGPS, which let you connect to an external GPS.

source: Conversation with spaces

Home Automation with ez430

Tuesday, February 9th, 2010

Now that the protocol for basic communication with the TI chronos ez430 has been worked out (see previous posts) I needed to work on something useful. So I set out to try and control my wireless light switch with the watch. Sadly the RF receiver supplied with the chronos does not use a protocol which is likely to ever be compatible with the arduino so this example requires a computer.

courtesy: chemicaloliver

Assemble your own solar panel

Tuesday, February 9th, 2010

Since there’s almost any size and shape of solar panel available for purchase from a myriad of vendors across the Internet why would anybody want to go through the hassle of tabbing together their own cells to build a solar panel? Because you can, obviously. This DIY video will run through the basics of chaining together polycrystalline cells and leaves the details like enclosure and such to the user.

courtesy: Make