 *主板芯片：STC8051U系列芯片 普中HC6800EM3 V2.2开发板搭建
 *详细情况：STC8051U LCD1602
 LCD1602_DB P0
 LCD1602_RS = P2^6;
 LCD1602_RW = P2^5;
 LCD1602_EN = P2^7;