电子琴，可以有不同的音节和音色及音调-The keyboards can have different syllables and timbre and tones

定时器可以发出不同频率，不同占空比的pwm波。当蜂鸣器接收这些波形时，由于频率和占空比的不同，它会发出频率及声音大小不同的响声，即不同的音色和响度。这样就可以唱歌了-The timer can emit different frequencies, different duty cycle pwm wave. When the buzzer receive these waveforms, due to different frequency and duty cycle, it emits s

matlab based timbre control design