基于I/O口复用的LED数码屏驱动的应用研究

Application And Research of LED Digital Screen Driver Based on I/O Port Multiplexing

本文针对目前家用电器中所使用的段码式LED数码屏的驱动控制方案进行研究,发现现有驱动方案占用单片机I/O口数量较多,数码屏的引出管脚数量多,PCB布局时占用空间多且不方便布线。本文在此基础上重新设计了LED数码屏以及驱动控制方案,该技术方案采用单片机I/O口直接驱动LED数码屏,该方案对LED数码屏灯珠逻辑重新进行了设计,使LED数码屏驱动管脚相较传统方案减少;并且通过单片机程序控制I/O口分时复用为LED显示屏的位驱动及段驱动。这样使得该方案能应用于结构限制的小型化产品中,同时可以有效降低产品成本。本文通过理论分析及实验验证,为LED数码屏的驱动控制设计方案提供了一些思路及建议。

This paper studies the drive and control scheme of segment coded LED digital screen used in household appliances at present,and finds that the existing drive scheme occupies more I/O ports of the microcontroller,leads more pins of the digital screen,and occupies more space when PCB layout is not convenient for wiring.On this basis,this paper redesigns the LED digital screen and the drive control scheme.This technical scheme uses the I/O port of the single chip microcomputer to directly drive the LED digital screen.This scheme redesigns the logic of the LED digital screen lamp beads,so that the LED digital screen drive pins are reduced compared with the traditional scheme;And the I/O port is time-sharing multiplexed into bit driver and segment driver of LED display screen through single-chip microcomputer program control.In this way,the scheme can be applied to small products with limited structure,and the product cost can be effectively reduced.Through theoretical analysis and experimental verification,this paper provides some ideas and suggestions for the drive control design of LED digital screen.