Ultra-low power consumption LCD liquid crystal display circuit module design circuit diagram

LCD display module : LCD liquid crystal display is an extremely low-power display device. It has small operating current, light weight, low power consumption, long life, and clear and beautiful writing. It is widely used in portable instruments and higher-end instruments for low-power applications. is widely used in. Pin 1: VSS is the ground power supply; Pin 2: VDD is connected to the 5V positive power supply; Pin 3: VL is the contrast adjustment terminal of the LCD. When connected to the positive power supply, the contrast is the weakest, and when connected to the ground, the contrast is the highest. When the contrast is too high, it will "Ghost", you can adjust the contrast through a 10K potentiometer when using it; Pin 4: RS is register selection, when the high level selects the data register, when the low level selects the instruction register; Pin 5: R/W is for reading and writing Signal line, read operation is performed when the level is high, and write operation is performed when the level is low. When RS and R/W are low level at the same time, instructions or display addresses can be written. When RS is low level, R/W is high level, Read busy signal, when RS is high level and R/W is low level, data can be written; Pin 6: E terminal is the enable terminal, when the E terminal jumps from high level to low level, the liquid crystal module executes Command; Pins 7-14: D0-D7 are 8-bit bidirectional data lines; Pin 15: Positive pole of backlight source; Pin 16: Negative pole of backlight source.

Display circuit principle analysis : The circuit design is shown in the figure. In the figure, DB0~DB7 of LCD1602 are connected to the P00~P07 ports of the microcontroller AT89C52, which are used to display the user's power consumption information; P25, P26, and P27 respectively control the register selection input RS and the read-write control input R/W of the LCD1602. , enable signal input terminal E; control the contrast of the liquid crystal display by adjusting the resistance value of R58.