I’m always astounded by how you can take a handful of loose electronic components and assemble a circuit that not only does something, but changes output as you interact with it. While printable circuits are a near-future prototyping option, these days I always start with a breadboard, itself an object of continual astonishment for me. That there is a standard in component design and sizing, and that you can populate a board with disparate parts that give them purpose is really quite fascinating.

Whether you’re following a comic, reading a book, or taking a workshop or even a high school class on laying out some circuit, you’ll ultimately want to take that breadboard circuit to the next level: Perfboard. That’s when “things get physical” and you have to start making design choices, whether your project is destined for an enclosure or simply to be held and played, like with the Light2Sound LDR Synth.

Named such because it converts light from a white LED into sound output on a mini speaker, the project only requires a few common components, including several that vary the output. Because of this it’s easy to lay out on a breadboard and customize in to your own light theremin-like project:


All the components route through a 555 timer, the backbone of hundreds of maker projects and a common IC (integrated circuit) to begin learning electronics. It has its own internal diagram, and can be configured for numerous modes and timing applications. It’s really fun to play with.

As noted, the real challenge was how to take the breadboard circuit and populate a perfboard, keeping in mind the circuit has sliding parts, and needs to be gripped with two hands:


The final project is designed for a right handed user, but could just as easily be flipped around — a la Jimi Hendrix on the guitar — to be controlled from the left hand. The momentary switch (which activates the circuit) is positioned so that in the right hand you will use your index finger, and in the left hand you will use your thumb, both strong fingers to drive the circuit. The other hand is then used to slide the LED in and out of the instrument’s tube:


I like the exposed circuitry, but have future plans to enclose everything, along with a line output for playing through a speaker. That said I’d love to see what other designs you come up with, and especially what tunes you choose to play! Here’s one song I’ve been toying with learning to get your week started off on a good square wave:

Weekend Projects is our beginner-friendly electronics series ranging from homemade circuits to interactive microcontroller projects. If you build this project as-is, or modify it to suit your needs, be sure to send us an email with pictures and a story about your build.