cleanup
waveform stepper function, additive scaling (a tolerable hack)
effect tweaks, waveform phase
debug packets
va_args doesn't seem to work with gcc-avr. so use a vararg macro for dbg_printf
debug packets
scale LED brightness to appear linear to the human eye using the CIE1931 colorspace. See http://jared.geek.nz/2013/feb/linear-led-pwm
better waveform rescaling