MT8880是DTMF信号的解码芯片，在智能电话控制中使用很多，这个里面有单独的拨号与振铃检测摘机的程序，每个程序都有详细的注释，非常好用-MT8880 is a DTMF signal decoder chip in the smart phone to use a lot of control, the inside has a separate dial-up hook and ring detection process, each program had detailed notes