Electronic Guitar Pick Tunes The Strings For You

November 23, 2009 by Mike Szczys 25 Comments

The Stimmmopped is an electronic guitar tuner made to be used as a guitar pick. This uses two LEDs synchronized to blink at the exact frequency of the string you are tuning. Pluck the string with the corner of the PCB and then shine the light on the string you are tuning. As the vibrating string moves back and forth it will only pick up the spot of light when the frequency matches that of the blinking LED. Once in tune, both red lights will appear to be constantly illuminated and immobile on the string.

An Atmel ATmega8 is used to control the device, interfacing with two buttons and a seven-segment display to choose the pitch currently being tuned. Gibson has a robotic guitar that features an auto-tuning mode, but if you don’t want to shell that much this low cost and simple build is for you.

[Thanks Sören]

Building Capacitive Sensitive Floor Tiles

November 22, 2009 by Mike Szczys 38 Comments

That title’s a mouthful but you’re already familiar with the technology and application of foot pads as sensors in games like Dance Dance Revolution. The usbddr project sought to make a USB connected DDR controller from scratch. The microcontroller used is an Atmel ATmega8 running the V-USB firmware for connectivity and uses the analog to digital converts to read in data from the capacitive sensors.

The physical implementation is cleaver. The base plate has a capacitor plate attached to the top of it and the tile has the other capacitor plate attached to the bottom of it. The two are separated by some weather-stripping which is spongy enough to allow compression, bringing the two capacitor plates together.

We’re not convinced of the long-term durability of the system. We certainly don’t think it will hold up to very much hard-core DDR playing. But we would love to see a Super Mario RPG style puzzle to unlock the door to the ‘castle’ at a child’s birthday party.

[Thanks Hans]

72 LED Persistence Of Vision Globe

October 15, 2009 by Mike Szczys 34 Comments

HaD-pov-globe

[Ben] told us about his POV globe yesterday. We took a look and saw just one photo and the code with no real explanation of his project. He certainly set to work over night and now we see all the goodies we look for in a great build log. He even threw the Hackaday logo up for our enjoyment. His build is well executed and he found some creative ways around the common problems in these projects. We take a closer look after the break. Continue reading “72 LED Persistence Of Vision Globe” →

Jamin’ To Bach, Commodore 64 Style

October 13, 2009 by Mike Szczys 25 Comments

[youtube=http://www.youtube.com/watch?v=MOhzkWZHBfM]

[thrashbarg] missed the sounds of the Commodore 64 and longed to hear the great masters in 8-bit glory. To get his fix, he created a midi device using the original Sound Interface Device from those long-dead systems. He’s interfaced the MOS6581 SID with an Atmel AVR ATmega8 microcontroller. The receiving pin for the AVR’s UART is used as a MIDI-IN connection, with the microcontroller converting midi data into the proper sound generation specs for the SID. The result is the 10 minutes of [Bach]’s Brandenburg Concerto heard in the embedded video above.

We have no idea where he picked up this obsolete chip, but if you want to give this a try, perhaps you’ll have some luck emulating the MOS6581 by using another ATmega8.

Web Controlled Dark Crystal

September 19, 2009 by Mike Szczys 11 Comments

mood_rock_using_shiftbrights

[Reza] sent in his mood rock. Unlike other “mood” devices, instead of showing what mood you’re in, it shows what mood the internets are in. Two ShiftBrite modules are controlled by an AVR ATmega8 which then connects to a computer via USB. The assembly is placed inside of a piece of alabaster.

USB communications are controlled by the ATmega8 running V-USB (formerly AVR-USB) firmware. [Reza] wrote some code to control the colors from the web using Perl and AJAX. Head over to the web interface to set the colors yourself. We’d love it if a live webcam was added so we could see our mood on the rock itself. Continue reading “Web Controlled Dark Crystal” →

Touch Sensitive Keypad

September 18, 2009 by Mike Szczys 12 Comments

capacitive_keypad

[Viacheslav] built a keypad that uses human capacitance to detect key presses. Unlike normal keys which close a physical connection, his project detects touch through the PCB substrate. He uses the analog comparator of an AVR ATmega8 to detect the moment of zero crossing and then measures the time it takes to discharge in order to detect key presses.

Continue reading “Touch Sensitive Keypad” →

Humanoid Robot + Homebrew Waldo = Big Smiles

August 24, 2009 by Phil Burgess 11 Comments

[youtube=http://www.youtube.com/watch?v=WCTvggKuPvU&feature=player_embedded]

Robot enthusiast [Vitalijus Rodnovas] built this rig to allow a humanoid robot to mimic his own body movements in real time. [Rodonovas] refers to his man-machine interface as a “master-slave suit,” but elsewhere this is often called a waldo after a prescient 1942 [Robert Heinlein] novella. This project page is slight on details and is mostly written in his native Lithuanian, but the pictures speak volumes, and with a little help from Google Translate we can learn the essential facts: The robot itself is a commercially-available kit, the Kondo KHR-1HV from Japan. The custom-built harness uses a collection of surplus Soviet-era military potentiometers (acquired on eBay) to read the positions of his elbows and shoulders, then an ATmega8-based interface board translates these readings into motion commands sent to the robot’s onboard controller. Some additional notes and code can be found on the RoboSavvy Forum.

Does it work? Just watch. His grin as the video progresses is infectious!

Hack a Day has previously covered other Waldos, but this latest deserves style points for its lightweight simplicity.