__ __         __            ___           
  / // /__ _____/ /__  ___ _  / _ \___ ___ __
 / _  / _ `/ __/  '_/ / _ `/ / // / _ `/ // /
/_//_/\_,_/\__/_/\_\  \_,_/ /____/\_,_/\_, / 
retro edition                         /___/ 
Now optimized for embedded devices!!
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Wardriving for Zigbee

posted Feb 29th 2012 3:16pm by
filed under: radio hacks

Wardriving started out as a search for unprotected WiFi access points before hot spots were prevalent. And so this ZigBee protocol wardriving hardware which [Travis Goodspeed] put together really gives us a sense of nostalgia for that time. Don’t get us wrong, we love our pervasive WiFi access and don’t wish to go back to simpler times. But if the radio signals your looking for are scarce, locating them provides a challenge.

Regular readers will recognize that [Travis] is interested in all things RF. One of his projects included sniffing wireless keyboard packets out of thin air and displaying them on the screen of his Nokia N900. This is right along those lines but he’s upgraded to an N9 phone for the display hardware. He switched up the RF hardware, using a TelosB (a board he’s already familiar with) to get on the 802.15.4 ZigBee spectrum. This dev board has an expansion port which let him use an RN42 module for wireless communications with the phone. This means the sniffing hardware can be hidden away in a backpack or jacket. After all, nobody will question someone walking around staring at a smart phone.

AVR: the facts about flash memory

posted Jan 24th 2011 5:00pm by
filed under: Microcontrollers

Here’s a nice little discussion about reading and writing AVR flash memory that [Windel] put together. He’s using an In System Programmer to read the flash memory from an ATmega328 using AVRdude, the programming software which we used in our AVR Programming Tutorials. He covers the particulars of the commands, how this might be useful, and finishes up with the gotcha’s involved in reading back code from the chip. We recently tried this out with that LED light bulb but were unsuccessful because the lock bits on the ATtiny13 chip had been set in order to protect the firmware from our prying eyes. Hopefully you’ll have more luck with these methods.

Keyboard composes its own music

posted May 1st 2012 6:21am by
filed under: musical hacks

Summer is right around the corner and all the final projects from electronic design classes are rolling into the tip line. This time, we’ve got [Chaorong] and [Siyu]‘s auto-composing keyboard from their time in ECE4760 at Cornell.

The keyboard has two modes: a ‘happy’ mode and a ‘tender’ mode, the difference being the tender mode is slower and sounds a little like a lullaby. After two keys are pressed, the ATMega644 figures out what key it should play in and starts generating a random-ish sounding song using a Markov probability matrix.

There’s a third option for the keyboard as well: play a short melody and the software will loop through a few permutations of the melody. After the break, you can see [Siyu] play Ode to Joy and have the autocomposer improvise around the tune. Very, very nice work and we can’t wait to see more senior design projects hit the tip line.

Creating a voice controlled robotic arm

posted Oct 19th 2011 6:01am by
filed under: robots hacks

robotic_arm_voice_control

[Arthur] was laid up with a wrist injury, so he decided it would be a great time to hang out around the house and tinker with electronics, since most outdoor activities were out of the question. He picked up a robotic arm kit and assembled it to test out some code written for it that he found online. Since typing commands into a terminal was awfully cumbersome considering his injury, he figured he might as well construct a voice control system for the arm.

He documents his work in a three part series, covering the process from concept to completion. The first part centers around the creation of the vocabulary and grammar for the voice recognition system, along with the how the grammar model was trained using voice samples.

The second and third portions of his tutorial deal with the software’s decoding of his commands and the Python scripts used to translate those commands into something the robotic arm can process.

[Arthur’s] voice control system works pretty well as you can see in the video below, though he already has a wish list full of improvements he hopes to make in the near future.

Compaq motherboard power mod

posted Jul 9th 2009 6:21am by
filed under: pcs hacks

cpq2atx_brd2

Some companies insist on using proprietary pieces. It can be really frustrating when there is no apparent reason other than consumer lock in. It irritates us to feel like we’re being forced to buy their pieces. This is one of the more popular reasons listed when you ask a hacker or modder what got them started.  This project takes us through making a normal power supply work with the compaq proprietary 14 pin plug found in some smaller desktop PCs.

Aside from the plug itself being different, the motherboards require a 3.3v standby voltage. A normal power supply usually only has a 5v. Though there are even simpler ways of bypassing the issue, he chose to put an inline voltage regulator. Schematics are available on the site.

[via Hacked Gadgets]


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