In the Adafruit Arduino Lesson 10, Pseudo-Theramin, an Arduino Uno is combined with a light-sensitive cadmium sulfide (CdS) photocell to make a light responsive music machine. This project allows you do do the same with an Adafruit Trinket or Gemma mini-microcontroller. This project costs less and works in smaller circuits or wearable projects.
Changes in light intensity on the photocell will change the pitch of a note on the piezo speaker as you wave your hand in front of the cell. While not a true theramin (which uses changes in a circuit’s reactance), this project is much simpler to build.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.