MAX7219与单片机的连接只需要3条线：LOAD（CS）片选引脚、CLK串行时钟引脚、DIN串行数据引脚。其中C1 为电源滤波电容，R1用来设置段电流。-MAX7219 single-chip connectivity with only three lines: LOAD (CS) Chip Select pin, CLK Serial clock pin, DIN serial data pin. Which filter capacitor C1 to the power, R1 to set the current paragraph.