Follow along as we first populate a perfboard with some common components, a low-power TLC555 Integrated Circuit, a speaker, and then mount the circuit on… a pencil! With the “Drawdio” Musical Pencil you, too, become part of the project. Due to the slightly conductive nature of graphite, combined with the conductive nature of the human body, the tones emitted from the speaker vary based on the resistance between those two points. Basically, if you move your finger around on a drawing – or conversely, if you keep your finger still and move the pencil lead around on a drawing – you’ll hear different sounds. Watch the video below to see and hear the project in action.
Of course your drawing must be entirely connected for this to work. That is, you must be able to trace a path from your finger to the tip of the pencil on the drawing. That is because you the human are in fact part of this circuit:
You should feel free to experiment with this setting and give us your feedback. Did you find an especially conductive pencil? Did you make a drawing that produces some truly unique sounds?
The Drawdio is already a classic beginner-friendly electronics project, having been previously modded onto a paintbrush and even kitchenware. What other hacks or modifications for the Drawdio will you come up with? Send pictures and a story of your novel build to firstname.lastname@example.org or leave a note in the comments below!
TIP: We used a carpenter’s pencil because they are easy to grip, easy to wind wire around, and their thick graphite core allows for the thumbtack to be easily inserted into the top. When sharpened correctly they also provide the artist or carpenter with the ability to make either thick or thin lines depending on which way you hold the pencil. Use this technique in your drawings to see how different line types and thicknesses effect the sounds produced.