[ Science Tutorial #2 ] – “Drawdio” Musical Pencil !
Drawdio: A pencil that lets you draw with music!
A lot of fun with instant gratification! Essentially, its a very simple musical synthesizer that uses the conductive properties of pencil graphite to create different sounds. The result is a fun toy that lets you draw musical instruments on any piece of paper.
How does it work?
The Drawdio kit is pretty simple compared to most electronic projects.
Parts list
Use it!
• Try different kinds of paper, and pencils. Mechanical pencils are great, but require a little more work.
• Place a copper coin (like a penny!) on the drawing and use that to make contact with the graphite - it will make the surface area larger and reduce the resistance of the drawing.
• Hold hands with someone and 'draw' on their skin with the pencil.
• Wash and lightly dry your hands to make them a little more wet than usual, this will also affect the pitch.
• Use graphite slugs, available at an art store, instead of a pencil.
• Just hold on to both sides and try twisting and pressing to make different tones.
How to use!
The Drawdio is simple to use. Simply grip the pencil in one hand so that you're making good contact with the copper tape. Then draw a circle on the paper and touch it using a finger from the other hand.
This allows your body to act as the sensor. The voltage is very low (about 1 volt) which is very safe. As long as you stick to the single battery, there are no health risks.
Using a copper coin between your finger and the graphite will improve the conductivity. Washing your hands and then drying them will also help, especially if you have drier skin or live in a dry climate.
Download
Board layout in EagleCAD format
http://learn.adafruit.com/system/assets/assets/000/010/155/original/drawdio2.brd
Some of the contents are quoted here.
https://learn.adafruit.com/drawdio
Video ! (Special thanks to @elysion for video)