Sebastian Tomczak, aka little-scale, has built a homemade drum machine around the Teensy 3.6, entirely on a solderless breadboard!
Sixteen button/LED pairs for step sequencing, two 74HC595 shift registers, five further buttons/LEDs for drum/pattern selection and pattern length, and a potentiometer for tempo control are all intricately wired to a pair of large breadboards.
The four channels provide kick, snare, noise-generated hi-hat, and percussive synth samples. Each voice has sixteen steps and four patterns. Each sample channel has 16 samples to select from, and a low-pass resonant filter tailors the overall output. Nanoloop, Pocket Operator, and Sync 24 (DIN sync) help it play nice with other gear. Learn more on the little-scale blog, and check it out in action in the video below!