I really love using the Teensy micro controller. It goes almost into every project I do, from art installations to MIDI controllers and instruments.
That’s why I developed a small break out board with some of the most common features I use.
It break outs the digital and analog pins in groups also a 3.3V, VCC, and GND bus. A voltage regulator circuit for running on batteries or external power supplies, opto-coupled MIDI in and out, an I2C two channel DAC chip with low pass filters and a breakout for the Teensy A14 DAC line.
A small generic board to be used in sound projects.