Specification: A single module can drive an 8*8 common cathode matrix Module working voltage: 5V Module size: 5x3.2x1.5cm/1.97*1.26*0.59in With 4 fixing screw holes, the hole diameter is 3mm, which can be fixed by M3 copper pillar Module with input and output interface, support multiple module cascade Wiring instructions: 1. The left side of the module is the input port, and the right side is the output port. 2. When controlling a single module, you only need to connect the input port to the CPU 3. When multiple modules are cascaded, the input terminal of each module is connected to the CPU, the output terminal is connected to the input terminal of the second module, the output terminal of the second module is connected to the input terminal of the third module, and so on...   Take 51 single chip microcomputer as an example: VCC - 5V Grounding - Grounding DIN - P22 Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement. Included: 1 x MAX7219 Dot Matrix Module 5 x Wires 1. Integrated Display Driver: The MAX7219 is a versatile serial input/output common cathode display driver that connects microcontrollers to 8-bit 7-segment LED displays, bar graph displays, or even 64 individual LEDs. 2. Convenient Serial Interface: With a simple four-wire serial interface, this module can be easily connected to most microprocessors. Each data can be addressed individually without the need to rewrite the entire display, offering flexibility and efficiency. 3. Extensive Functionality: The MAX7219 includes an on-chip B-type BCD encoder, multiple scan circuits, segment drivers, and an 8x8 static RAM for data storage. It also features an external register for setting the segment current of each LED. 4. Low Power Consumption: Operating in a low-power shutdown mode of just 150μA, this module offers both analog and digital brightness control. Additionally, a scanning limit register allows users to display 1-8 bits of data, and a detection mode illuminates all LEDs for easy testing.