A step sequencer is one of the easiest kinds of electronic music “synthesizers” to learn how to use. Synthesizer is in quotes there because many step sequences are just playing prerecorded clips, and aren’t actually generating sounds in real time. That makes them ideal for certain applications, such as drum machines, because the musician just needs to pick a sound and choose which steps in a beat to play it on. The Teensy Beats Shield is a simple step sequencer you can build yourself, and that is designed specifically to be hackable.
Teensy Beats Shield was created by Chris Miller after he noticed that most commercial step sequencers, like the Pocket Operator for example, are closed source and aren’t intended to be modified. Miller already had a Teensy 3.2 laying around, and he decided to use that to build his own step sequencer since the Teensy has DSP (digital signal processing) capabilities. What he came up with is the Teensy Beats Shield, which is a complete step sequencer in a handheld, open source, hacker-friendly package.
You can interact with the Teensy Beats Shield through four rotary encoders and 20 buttons. The interface is displayed on a 2.4″ TFT LCD touchscreen, and each of the 20 buttons has its own RGB LED to indicate when it’s active. Battery charging is handled by an Adafruit Powerboost 1000c, and a Teensy audio shield provides an amplified DAC headphone output. If you want to build your own Teensy Beats Shield the bare PCB is available on Tindie and instructions are on Hackaday.io.