Audio tune generator

1. Use LUT-DMA-PWM generate two sine-waves, (100, 300 Hz nominal), max harmonic distortion 0.5%
2. GUI to change Amplitude and frequency of the sine wave. need source code in C/C++

The sine-wave will be tested with dspic33ch512MP508 and DRV8833 to drive a speaker. harmonic distortion will be validated with FFT app.