Lava Lamp Centrifuge

March 8, 2010 by Caleb Kraft 72 Comments

[youtube=http://www.youtube.com/watch?v=8-i9iI0ZA4M]

Like many projects, this one started with a harmless question. “Will lava lamps work in a high-gravity environment such as Jupiter?”. Well, as it turns out, this harmless question was not so easily answered. The only real solution was to test and prove for sure. To do this, [Neil Fraser] built a centrifuge in his living room. At 10 feet across and roughly 50 kilograms, this is no small toy. The end with the lava lamp is set to pivot, so at a stand still, it is positioned vertically and at full speed it is positioned horizontally. The whole process is recorded on video for proof. So, does a lava lamp work in high gravity? Watch the video or read the article to find out.

[via Makezine]

Automatic Telephone Recorder

March 2, 2010 by Mike Szczys 40 Comments

[James Bond] types and those suffering from a hefty dose of paranoia can now record all telephone conversations. [Trax] built this module that monitors the phone line and starts recording when a handset is picked up. A computer does the actual recording, triggered by the microcontroller via a USB connection.

We like the use of an old PCB for a faceplate, we’ve certainly got some duds of our own sitting around. The three cords are a bit confusing though. One for the phone line, one for the USB, but what does the third do? Is it an audio-out connection?

We’ve asked [Trax] to post a schematic and source code if possible so that might clear up the mystery.

Update: [Trax] let us know that there is a red button with white lettering at the bottom labeled “download”. This contains schematic, code, pcb layout, and PC software. We just missed it the first time around.

Phone/webapp Written In Ploy To Appear More Popular

March 1, 2010 by Mike Szczys 20 Comments

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?

More Cellphone Controlled Door Locks

February 23, 2010 by Mike Szczys 16 Comments

[Tom Lee] and his colleagues 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.

Continue reading “More Cellphone Controlled Door Locks” →

Serial Communication With Cell Phones

February 23, 2010 by Mike Szczys 20 Comments

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.

Android 2.1 On Four More HTC Handsets

February 21, 2010 by Mike Szczys 14 Comments

Tired of fighting Windows mobile on your HTC handset? Now you can fight a beta ROM of Android 2.1. [Slm4996] has put in a flurry of work over the last few days to get Android 2.1 running on the HTC Kaiser (aka AT&T tilt), Vogue, Niki, and Polaris. Right now everything except the camera and bluetooth is working but there is a bug tracker to help with troubleshooting any undiscovered issues. If you want to try it out but don’t want to flash the hacked ROM to your phone you can run it beside Windows Mobile by using HaRET.

Correction: The title of this post originally read “Droid 2.1” in error. We have corrected it to read “Android 2.1”. [Thanks GuyFrom7Up]

USB Host Mode For Droid

February 10, 2010 by Mike Szczys 41 Comments

There’s a simple hack to use your Motorola Droid phone as a USB host. It is a hardware-only hack that doesn’t require you to crack open your phone, root it, or even to change firmware (although device drivers in the stock Android image may be quite limited). The dongle above is used as a key to enable the mode while the phone is booting. This was repurposed from a car charging cable by removing the wires and resistor and shorting the resistor pads. Once the phone is in host mode the dongle is swapped for a simple USB-mini to USB-A socket adapter, built from two cables you probably have lying around. Now you can plug in any device you want.

[Thanks Freezer90]