通过7279实现4*4矩阵键盘扫描和数码管显示

键盘键码为1-16，当键码小于10时，数码管只有第一位显示

高位自动消隐-By 7279 to achieve 4* 4 matrix keyboard scanning and LED display keyboard key code is 1-16, when the key is less than 10 yards, the digital control only the first one shows a high auto-blanking