What is the basic working principle of Shandong LED display?

An LED display is an electronic display composed of an LED dot matrix. It can change the content displayed on the screen, such as text, animations, and videos, by turning the red and green LED beads on and off. It can display and control components through a modular structure. It mainly consists of display modules, control systems, and power systems. The display module is an LED light dot matrix forming a luminous screen; the control system controls the lighting within the area to change the content displayed on the screen; the power system converts input voltage and current to meet the needs of the display.

The basic working principle of the Shandong LED display is dynamic scanning. Dynamic scanning can be divided into two modes: row scanning and column scanning. The common mode is row scanning. The row scanning mode can be divided into 8-row scanning and 16-row scanning.

In row scanning mode, each LED dot matrix chip has a set of column drive circuits. The column drive circuit must have a latch or shift register to lock the font data to be displayed. In row scanning mode, the same row control pins of the same row of LED dot matrix chips are connected in parallel to one row, totaling 8 rows, connected to the row drive circuit; the line drive circuit also has a latch or shift register to latch the line scan signal.

The column drive circuit and row drive circuit of the Shandong LED display are generally controlled by a microcontroller, commonly the MCS51 series. The content displayed on the Shandong LED display is usually stored in the external data memory of the microcontroller in the form of 8-bit binary font data.

The process of controlling the Shandong LED display with a microcontroller is read first, then write. According to the arrangement order of the LED dot matrix on the screen, the microcontroller first drives the latch to one row of an LED dot matrix array, writes the font data read from the external data memory, then writes the font data to the second and third blocks... until the font data is written to one block in that row. Then, the microcontroller drives the latch to write the row scan signal to the row so that the LEDs related to the font data in that row light up. Then the first row in the second line, the first row in the third line... until the first row in a line is lit. After one row is lit, there is a delay, then the screen goes black. In this way, the microcontroller completes the scanning control of the Shandong LED display.

The microcontroller performs scanning control on the second and third rows of the Shandong LED display... until the eighth row, the process is the same as the first row. After all 8 rows are controlled, the Shandong LED display completes the display of one frame of the image.

Although the Shandong LED display lights up line by line in this way, only one line is lit at a time. As long as each line can be lit more than 50 times per second, that is, the refresh rate is above 50 Hz, due to human visual persistence, the image displayed on the Shandong LED display still appears as a full-screen stable image.