These are older projects using single board microprocessors built on a Forth Programming Language platform. Forth language has the advantages of both a higher level language and assembly code.

PIC Microcontroller chips by Microchip are ideal for small projects. Here they are used for single function MIDI devices. They can be programmed in assembly code using MPLabs, or with a super easy BASIC language if you use the PICAXE company products.

The Arduino Maker community is huge and there are a wide variety of boards to choose from. This is my usual go-to microprocessor board for a wide variety of projects. Here we go from the tiny ProMicro to the hefty Mega to the latest MKR_Zero board.

The ESP32 is a big step forward in speed and power for single board microprocessors. Many versions have come out with specialized capabilities. Here we use one with an integrated audio Codec ideal for audio signal processing.

Controller for Pure Data.
Sample & Hold Circuit.
Aural Exciter Vibrator.