按下矩阵键盘第一行时以1200bps发送1,2,3,4,第二行时以2400bps发送5,6,7,8， 第三行时以4800bps发送9,10,11,12，第四行时以9600bps发送13,14,15,16-Press matrix keyboard to send the first row to 1200bps 1,2,3,4, 5,6,7,8 a second transmission line to 2400bps, 4800bps send 9,10,11,12 third row t