The LCD display hardware circuit design of the station announcement system using AT89C51

　　Circuit principle: The LCD module is divided into byte units. In a single screen, there are 8 pages, each page has 8 rows, and each row has 64 bits (i.e. 64 columns). Like computers, the data in the LCD dot matrix display controlled by the single-chip microcomputer is also represented by "0" and "1" codes. Generally, "0" represents no display data, and "1" represents display data. Different characters will be displayed according to different codes. The display points on the display correspond to the display cache RAM in the driver control chip  one by one, that is, one bit in the font represents one pixel in the LCD  display, and the point selection method is from left to right and from top to bottom. Here, a 16 × 16 dot matrix output is used to display each Chinese character, so a square composed of 256  dots on the screen is required to display it. One byte corresponds to 8 dots, so one Chinese character needs 32 bytes to store and display. "Chinese font dot matrix data batch generation tool" is a software that uses this principle to realize Chinese character encoding.

　　The Chinese characters involved in this design are batch-generated into 16 × 16 dot matrix codes using software modulo and placed in the TA2BL E table in the ROM  area. Through logical control, the codes can eventually be read out to the hardware drive circuit to display different Chinese characters.