FPGA 电子琴音乐演奏器。使用频率计，计算音乐谱的不同发音，用蜂鸣器发音，实现音乐演奏。-FPGA keyboard music player. Frequency meter, calculate the different pronunciation of the musical spectrum, buzzer pronunciation, the music played.

测量信号频率，为2015电赛频率计解决方案(Measure the signal frequency for the 2015 race frequency meter solution)