Digipot
Digital potentiometer with rotary encoder and PWM output using a Microchip PIC
A Microchip PIC12F675 is the heart of a digital potentiometer. A rotary encoder is used for the twist, while 2 buttons provide a means to limit the minimal & maximal settings.
The output is PWM-signal, so any kind of circuit can be used to drive whatever one wants
The program is written in JAL