About the LED display common signal details

LED is a light emitting diode, the English abbreviation of light-emitting diodes, referred to as LED. The light-emitting diodes show a new generation of information media and are widely used in modern life. LED has the advantages of energy saving and environmental protection, and is the backbone of urban lighting engineering. The principle of LED light-emitting technology is that certain semiconductor materials emit light of a specific wavelength when passing current. This kind of power-to-light conversion efficiency is very high. Different materials used for different chemical processing can obtain various brightness. And perspective LED. It is a kind of screen for displaying various information such as text, graphics, images, animations, quotes, videos, and video signals by controlling the display of semiconductor light-emitting diodes. The following is an explanation of the commonly used signals and concepts of LED large screens.

A, ABCD line signal: ABCD is the line selection signal, only exists in the dynamic scanning display. ABCD is actually a binary number and A is the lowest bit. If binary representation ABCD signal is used to control the maximum range is 16 lines (1111). For example, the AB signal has a range of 4 lines (11), so only the AB signal can be used for 1/4 scanning. When the line control signal is abnormal, LED display will show misplaced, highlighted or image overlap.

Second, the data signal: used to provide the data required to display the image. There must be a clock signal to coordinate the data to the display point. Generally, the display data signal is separated. If a data signal is short-circuited positively or negatively, the corresponding color will appear bright light. When the data signal is interrupted, the corresponding color display is indefinite.

Third, the CLK clock signal of the LED display: CLK (CK) is the clock signal, provides the shift register and shifts the pulse, each pulse will cause the data to enter or leave a place. The data on the data port must coordinate with the clock signal to transmit data normally. The frequency of the data signal must be 1/2 times the frequency of the clock signal. In any case, when the clock signal is abnormal, it will make the entire LED display screen clutter.

Fourth, STB latch signal: STB (LT) is a latch signal, the role is to send the data in the shift register to the latch, and its data content through the drive circuit to light up the LED display. The latched signal also needs to coordinate with the clock signal to display the complete image. In any case, when the latch signal has an abnormality, the entire LED display screen will be disorganized.

V. EN enable signal: EN is the display enable, N is the ground (GND). Confirm that the interface between the unit board and the control card is the same, and you can connect directly. If they are inconsistent, you need to make the transition lines yourself (convert the order of the lines). The full screen brightness control signal can also be used to show blanking. Just adjust its duty cycle to control the change in brightness. When the enable signal is abnormal, the entire screen appears bright, dark or brightly smeared.