PIC Based Analog Synthesizer Known as PICSynth

The project aims to provide the functionality of analog and early digital synthesizers from the 70s as it uses two oscillators and easy to get components to be able to produce a wide range of sounds.

One of the oscillators used functions as a tuning switch as it creates square, triangle, or ramp waveforms while the other oscillator is in charge of the level as well as the pulse width. A waveshape circuit shows at the back of oscillator panel. The PIC square wave is divided into lower octaves by the dual waveshape as the square wave is converted into an approximation of sawtooth simultaneously. A pulse width adjustable square wave is produced by feeding the sawtooth into a comparator.

An 18-pin PIC microcontroller and keyboard decoder can be seen in the PIC board. the three outputs produced by the PIC include two oscillator outputs, either in-tune or detuned and the other is a trigger output for triggering envelope. Through 74HC154 decoder using top key priority, the keyboard is being scanned by the PIC. To produce two oscillators in tune, it requires speed and accuracy by programming the PIC in assembler.
Read more