44780 16x2 字符液晶屏驱动演示程序总线方式连接线图:LCM-------51 LCM-------51 LCM--------51 DB0-----P0.0 DB4-----P0.4 RW-------P2.0 DB1-----P0.1 DB5-----P0.5 RC-------P2.1 DB2-----P0.2 DB6-----P0.6 E--------P2.7 =>74ls00+wr+rd DB3-----P0.3 DB7-----P0.7 VLCD接1K2电阻到GND