Build your own SMS chatroom

While he was organizing a party, [Mike Seese] hit upon the idea of chatroom that would operate over SMS. Not being content with the ‘reply all’ function, [Mike] built a Group Messaging Service that runs on his home server.

The chat room is initiated by sending a text to a server. Your friends then reply, and the chatroom is then opened. The project was written in C++, and [Mike] put everything on github for your perusal. The software does use libraries from /n software’s IP*Works, but if you have any trouble obtaining those libraries feel free to drop [Mike] a line.

The great thing about this project is the fact that it’s platform independent – as long as a phone can do SMS, it’ll work. Seems like a great thing for those of us still using the old Nokia ‘bar’ phones. An SMS chatroom has been done before but this is the first time we’ve seen a build that will run off your server, and not internet-based services.

While it may not be the best idea for people without unlimited texts on their phone plan, it’s a really great idea and we’re wondering why something like this isn’t available via Google Voice.

Quick & Dirty USB phone charger

usb_phone_charger

Hackaday forum member [Dan Fruzzetti] wrote in to share a simple, yet useful hack he built just the other day. He and his wife both have Evo 4G smartphones and they were pretty disappointed in the lack of portable charging solutions available.

Instead of buying something and modifying it to his needs, [Dan] decided to build a quick and dirty charger instead. His ghetto-mintyboost was built into a cheap project box he found at Radio Shack, which is stocked with a set of four D-cell batteries. The batteries were wired in series and connected to a pair of salvaged USB ports mounted on a small piece of protoboard.

Knowing that most portable devices get 5.7v from their chargers already, he was not worried about hooking his phones straight into the 6v battery pack he built. He says that the phones actually charge pretty quickly, and that he estimates he should be able to get about 50 charges out of the box before he needs to swap the batteries.

This is not a complex hack by any means. It is quick & dirty, solves an annoying problem, and it’s dead simple to build. That’s exactly why we like it.

Phone/webapp written in ploy to appear more popular

That title’s not really fair to [Evan], but he did write a cellphone tetris game that causes your handset to automatically telephone him if you win. He’s using two applications that we’re not very familiar with, Twilio and Tornado. The former handles control input from the cellphone via their simple API. The latter is a web server and web framework that runs the actual game.

If you’re interested in how he put the two together you can poke around in the code. If you really don’t care about how it is done, you might just want to win the game, automatically giving [Evan] a call, running up his wireless bill in the process.

Help us add some value to this article by leaving a comment.  We’d like to know how Twilio compares to Google Voice which doesn’t seem to have a published API (but there is some work in that area). We also think web-based cell phone interactivity, already popular in hacks, is just beginning to build some steam. What are the tools you use to make cellphone interfaces easier and quicker to implement?

Serial communication with cell phones

Hackaday alum [Will O'Brien] 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.

GSM Cracked

[Karsten Nohl], with a group of security researchers has broken the A5/1 Stream Cipher behind GSM. Their project web site discusses their work and provides slides(pdf) presented at 26C3. A5/1 has had known vulnerabilities for some time now and is scheduled to be phased out for the newer KASUMI or A5/3 block cipher. This should be an interesting time in the cell phone business.

Thanks to [Tyco] and [MashupMark] for pointing us to this story.

Vodaphone ringtone music commercial

When we first saw Vodaphone’s ringtone commercial where 1000 cell phones perform a section of the William Tell overture, we just assumed it was some slick video editing, not to be taken seriously. Apparently, we were wrong. They actually did this. They actually sent text messages to all the phones in correct timing to play the music.  In the video after the break, you can see some details on how they pulled it off. They had to perform this during non peak usage hours to ensure that all their texts went through. We think this project is pretty impressive. Actually, we still don’t know how they pulled it off, we can’t seem to predict how long a text message will take to reach its destination with any kind of reproducible accuracy.

[Read more...]

DIY cell phone alti-variometer

AltiVarioFront

[Vlad-Andre] used some of his free time to build an alti-variometer. He does some para-gliding near restricted air space and wanted a backup altitude warning that would help keep him below the mandated altitude. His solution uses the SparkFun Weather Board in conjunction with their BlueSMiRF dongle to measure altitude and transmit it via Bluetooth. From there, he wrote a program to grab the transmitted data with his cell phone and display the information. His application also has the ability to set altitude warnings and log changes over time.

Using this system he is able to get altitude data with 3.5 inch accuracy. Because the capture application is written in Java it should be easy enough to make this work on other cell phone models. The project is clean and works well but we estimate the cost of the parts to be between $250-300, making it out of reach for those who don’t have a specific need for these types of measurements. This is especially true for paragliders who have much less expensive options available to them.
[Thanks Carl-Emil]