Monthly Archives: April 2013

LED Flasher

I made a simple LED flasher based on the schematic below. The only difference is that I used two 22kΩ resistors instead of 100k.

Parts list: LED x 2, 22kΩ x 2, 470Ω x 2, 10μF x 2, 2N3904 transistor x 2, SPDT switch x 1, 9V battery x 1.


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Arduino Keyboard v5.1

# Everything is contained within the case.

# The battery can be easily removed and changed.

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Arduino Keyboard v5.0

Originally I was thinking about laser cutting an acrylic case for the keyboard, but later decided to just use some cardboard and super glue (and some tape…) to make a rough looking case. I’m a complete noob at soldering. The soldering process took me about 8 hours, and designing & making the case took me one and a half. The dimension of the case is roughly 17.4 cm * 6.2 cm * 2.3 cm (front hight) ~ 3.6 cm (back). Under the protoboard is an Arduino and a 9V battery. I think the next step for this project is to figure out a way to replace the Arduino with just a single ATmega328 chip, making the keyboard even cheaper and thinner.
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Inside the case:

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Arduino Keyboard v4.1

In this version:

# Supports multiple simultaneous key presses (finally I can play some chords on it).

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The code is available at the link below. I’m fairly new to C/C++, so it’s not one of the most elegant code I’ve ever written.

Serial Midi Converter from SpikenzieLabs:

Also, I’ll try to put the schematic up as soon as possible.