Wednesday, October 31, 2012
Thursday, October 18, 2012
I've completed (modified code) a synthesizer built on the MSP430 Value Line Launchpad. It uses the msp430g2452 chip. It has MIDI input and two oscillators- osc 2 can be detuned and mixed in at different volumes.
This is based on NatureTM's simple midi synth on the 43oh forums. It. uses Pulse Width Modulation to create its sounds==> no DAC used, it is a 1-bit output synth. There is something similar(but without MIDI control) on another MCU platform. Unlike that PWM version, this has the cycle time variable on the first oscillators pitch, so there isn't a whine from a fixed cycle-- the duty cycle controls the sound of the second, detuned oscillator. Detuning and volume of oscillator 2 are controlled thru midi messages, ( MIDI CC's 1 and 7 here).
Not too bad results for a $4.30 dev board an a few parts, IMHO. I'll post the code and a clip as soon as I clean it up. No envelope yet, I haven't successfully added even an attack control, odd things start happening when I try to add that in, wondering if I'm hitting limitations of the comp speed(?).