Nowadays, young people like to go out shopping at night, and people are not affected by the dark night, not only because of the lights and street lamps in the store, but also the signs hung on various occasions. These signs are led dot matrix writing display, they can display two-dimensional, three-dimensional, video, TV, VCD programs and live, etc. Now led dot matrix writing display is no stranger to us, but we have little understanding of its details, today we will introduce it in detail.
Function realization
(1) Under the “light up” function, when the light pen touches a point LED on the screen, it can immediately light up the point LED, and synchronously display the column coordinate value of the point LED on the controller (the upper left corner is the origin of the column coordinate).
(2) Under the “highlight” function, when the light pen is quickly across the screen, it can synchronously light up the LED points across, and its speed requires that it can streak and light 20 points of LED within 2s.
(3) Under the “reverse display” function, the information displayed on the screen can be reversed (that is, the font stroke is not bright, and the no stroke is highlighted).
(4) Under the “whole screen erase” function, the entire screen of information displayed on the screen can be erased.
(5) Customize display characters.
led dot matrix writing display design
This design is based on 16×16 lattice LED electronic display design. The dynamic design and development process of LED dot matrix electronic display based on STC89C52RC is introduced. This design consists of main modules: main control CPU module, key input module, light pen detection circuit, LCD information display, 16×16 dot matrix LED dot matrix display and drive module. In the design of the 16×16 dot matrix LED dot matrix display and drive module, the CPU output signal is first latched by 74HC245, and then the output signal is driven by the 38 decoder 74HC138 decoding gate APM4953, and the shift register 74HC595 is used as the column driver. The MCU control system program adopts C language for modular programming. Control the level of each display point corresponding to the anode and cathode end of the LED, you can effectively control the light of each display point. This paper introduces in detail the hardware design idea of LED dot matrix display, the function and principle of each part of the hardware circuit, the program design of the corresponding software, and the instructions for use. The dot matrix data of the displayed characters can be written by themselves (that is, direct dot matrix drawing), or extracted from the standard font library. The practice proves that the system has small display error, stable performance, reasonable structure and strong expansion ability.
LED dot matrix display module
LED module is the main module of this design. It is composed of latch, row drive and column drive. Among them, all the LED light drive signals are sent out from the P2 port of the control module, and then sent to the 4 common control ends of the 4 shift registers 74HC595 through the latch 74HC245, and the drive column; The other three outputs of the latch are connected to the 38 decoder 74HC138, and the decoded signal drives the corresponding line through the P-channel’s enhanced FET APM4953.
The led dot matrix writing display has the effect of attracting customers because of its gorgeous color, and it also adds rich colors to the city at night. With the development of science and technology, there are more and more electronic products around us, but science and technology has always been a double-edged sword, we should learn to make good use of them, but it will cause harm. We all know that there is a lot of pollution now, and optical pollution is a new type of pollution, so the led dot matrix writing display needs human security applications.
