The sampling data are displayed by 7 - segment leds that are designed in a dependent pcb , the display board has a serial interface which use less pins of mcu . it ' s a efficient way . at last the outputs by calculation and reference of fis control the capacitor - group and voltage adjuster by relay - group , the whole device is divided into three part , the first part is sampling & control board ; the second part is display leds board and the third part is supply & output board 在电压无功综合控制器的设计中，考虑到mcu管脚有限且要求显示的数据较多，使用了较多的spi接口形式的外围芯片(如cs5460a 、 ezprom ) ，而且将数码管显示部分设计为串行数据传输模式，这样其数据线也可以利spi接口的数据线复用，提高了mcu管脚的利用率也保证了功能的实现。
