Battery Capacity Tester

November 11, 2009 by Mike Szczys 16 Comments

battery-capacity-tester

[Moris_zen] built a device to accurately measure the capacity of batteries. He needed to have an accurate measurement for the batteries he uses in a RC airplane. Knowing the discharge time allows him to fly the friendly skies while avoiding crashes from lost communications.

He based the tester around the Arduino platform. Instead of using a pre-built Arduino board he referenced the open source schematics and built the device from components to fit his needs. His solution automatically detects the battery type (Lithium-Ion, Nickel Metal Hydride, etc) based on voltage when the battery is added to the circuit. It then uses a 2.2 Ohm resistor and ADC measurements to take the battery through a discharge cycle. A character display shows status information with the ability to track discharge information using a computer to graph the data.

Apart from flashing an LED this was his first Arduino project. It’s a great use of the platform and much more automatic than other solutions we’ve covered.

Bike Brake Light Senses You Slowing Down

November 9, 2009 by Mike Szczys 57 Comments

bike-brake-light

Group riding can be a bit dangerous if the pace is fast and riders don’t notice a slowing in the front of the pack. [WyoJustin] designed a brake light system for cyclists to try and remedy this issue. LEDs are mounted in the end caps of the handlebars on a road bike. When an accelerometer senses the bike slowing down the LEDs light up, warning those behind you that you’re slowing down.

The system is made to be portable, as a lot of serious riders have multiple bikes. To make this happen, all of the electronics are housed in the handlebar tubing for easy transfer. This includes an accelerometer with built in voltage regulator, an Arduino to control everything, and a battery. Take a look at the brake lights in action after the break.

Most of the bike lights we see are for the front of the machine, but this backward-facing package is a clean and easy solution we can get behind (safely).

Continue reading “Bike Brake Light Senses You Slowing Down” →

Centipede Shield Design Contest

November 8, 2009 by James Munns 19 Comments

4084880398_cc349acfa6_b

Our friend [Garrett Mace] from macetech has finished a prototype of a new shield which allows the Arduino (or any other microcontroller with I2C) to add 64 digital I/O pins using only 2 of the analog pins. Currently he only has a few pre-production boards, and rather than selling them he is throwing a contest to win them. The contest is looking for people who have a specific project in mind that could use the centipede, and on Friday November 13th he will pick his favorite two. To submit an idea, just head over the Arduino forums and post an idea complete with details and relevant schematics, etc.

We will be sure to follow up with the winners of the contest, as well as let you all know when the Centipede Shield makes it into production.

Urban Defender: Location Aware Game

November 7, 2009 by Jakob Griffith 30 Comments

[youtube http://www.youtube.com/watch?v=zrAFYava258&feature=player_embedded%5D

What do gangs, territories, cities, and glowing blue balls have in common? No, not that one drunken night you can’t seem to remember, rather a new location aware game called Urban Defender.

The concept behind the game is simple. A player hold a ball that knows its current location and can notify you if needed via LEDs and a speaker of changes in its environment. He or she then runs around the city until the ball tells them of an unclaimed or enemy territory. Bounce the ball against a building and that territory is now claimed.

The ball itself is a prototype combination of an Arduino, Accelerometer, vibration motor, LEDs, XBee, batteries, and wire all packed inside of an industrial rubber gym ball. Unfortunately after testing the Urban Defender team found the GPS and a few other components would need to be kept outside of the ball and on the player.

Finally, a project that warrants the use of an Arduino. Anyone up for a game?

Servoelectric Guitar Is A Keytar With Strings

November 6, 2009 by Mike Szczys 18 Comments

servoelectric-guitar

[Keith Baxter] has undertaken something of a ‘Mount Everest’ of guitar modifications. He’s developing a Servoelectric guitar that trades frets for a keypad. It is still a guitar in the sense that it has a body, strings, and pickups to sense the strings vibrations and pass them to an amplifier. The left hand, which traditionally would shorten the strings as needed by pressing them against a fret, now changes string pitch using a keypad. This is an interesting fusion between traditional guitar and 80’s phenomenon, the keytar.

Each string is connected to a different servo motor. When a key on the keypad is pressed, the corresponding servo adjusts the tension of that string, bringing it in tune at the new pitch. His original design involved a lot of custom circuitry but he’s evolved the project to include an Arduino controller. This second generation both simplifies the control circuitry and improves upon it.

We’ve embedded some video after the break. In the first example you can see the strings adjusting for each new pitch. In the second, take a look behind the guitarist… what do you think he’s got planned for those giant capacitors?

Continue reading “Servoelectric Guitar Is A Keytar With Strings” →

Physical Email Notification

November 6, 2009 by Jakob Griffith 60 Comments

One day computers will exist in every part of our lives. You’ll be standing in the shower, lathering up when Chantal, your holographic computer controlled AI partner, informs you in a cool voice you have a new email. How splendid, it must be the office letting you know there is no work today! “Anything else?” You ask; “Negative” her electronically synthesized voice responds.

Over at TINYenormous they’ve made this dream come true – minus the holographic computer controlled AI partner bit. Rather its simply a physical email notification system consisting of an LED and Arduino with some python code. We like the concept but prefer our Google Desktop with Gmail setup instead. Perhaps by using a small wireless server and rechargeable batteries, it could make a great dinner table centerpiece notifying you of the latest email. How simple, or how complicated would you make a setup?

[Thanks Madmaze]

[Update]

Rob created a very nice USB version.

Dan made a wireless version from XBee modules and includes an LCD.

J4mie is the original inspiration for the project.

Have your own notification system? Tell us in the comments, And we’ll place it here!

Didgeridoo Modded To Include Electronic Manipulation

November 6, 2009 by Mike Szczys 68 Comments

didgeridoo-sound-synthedsizer

It’s not a bazooka, but this altered instrument makes it look like the player is toking off of some type of weapon. [Kyle] wanted to take the already mysterious sounds produced by a didgeridoo then capture and alter them electronically.

The physical build of this project is nothing short of beautiful. He’s mounted several curved control boards to the outside of the instrument. The controls feature six push buttons, five toggle switches, and six potentiometers that interface with an Arduino. The sound is picked up by the device then sent along with the switch settings to a computer via Bluetooth. The computer then works its magic to create the wicked audio effects heard in the video after the break.

His article, linked above, includes several diagrams detailing the synthesis process. They’re a little beyond our understanding but if you know what’s going on, please share your insight in the comments.

Continue reading “Didgeridoo Modded To Include Electronic Manipulation” →