db-synth

A MIDI-controlled mono-voice digital synthesizer built on top of the AVR DB microcontroller series.

Why?!

I've been playing around the design of synthesizers (both analog and digital) for some time, and I'm a long time AVR user. When I noticed that Microchip released a new AVR DB series, that included internal DACs and operational amplifiers, building a digital synthesizer out of that was the only obvious thing to do! :D

Features

This synthesizer implements a single but reasonably capable voice, with the following modules:

Band-limited oscillator (tracks most of the MIDI note range, with decent tracking up to 8th octave):

• Square (not Pulse)
• Sine
• Triangle
• Saw

ADSR envelope generator (time parameters from 20ms to 20s, emulating AS3310):

• Linear curves
• Exponential curves (emulating AS3310)

Other features include:

• 48kHz/10bit sample rate.
• Fully controllable via MIDI.
• Current settings can be stored into the internal EEPROM as a preset.
• Second order reconstruction filter for signal output.
• OLED display for parameter monitoring.