Ultra low power LCD liquid crystal display circuit module design

LCD display module: LCD liquid crystal display is a very low power consumption display device, which has small operating current, light weight, low power consumption, long life, clear and beautiful writing, and higher-grade instrumentation in portable instruments and low-power applications. It is widely used. The first leg: VSS is the ground power; the second leg: VDD is connected to the 5V positive power supply; the third leg: VL is the liquid crystal display contrast adjustment end, the contrast is the weakest when connected to the positive power supply, the contrast is the highest when the grounding is high, and the contrast is too high. "Ghost", you can adjust the contrast through a 10K potentiometer when using it; 4th pin: RS is register selection, select data register when high level, select instruction register when low level; 5th foot: R/W for reading and writing Signal line, read operation when high level, write operation when low level, write command or display address when RS and R/W are low at the same time, when RS is low level R/W is high level Read the busy signal, when RS is high level R/W is low level, data can be written; 6th pin: E terminal is the enable terminal, when the E terminal changes from high level to low level, the liquid crystal module executes Command; 7-14 pin: D0-D7 is 8-bit bidirectional data line; pin 15: backlight positive; pin 16: backlight negative.
Display circuit principle analysis: circuit design as shown. In the figure, DB0~DB7 of LCD1602 is connected with P00~P07 port of single chip AT89C52 to display user power information; P25, P26, P27, register selection input RS of LCD1602, read/write control input R/W Enable the signal input terminal E; control the contrast of the liquid crystal display by adjusting the resistance value of R58.