MAX7219 Dot Matrix 4 In 1 8x8 Display 5P Line Module For ArduinoFeature:A single module can drive a 8x8 dot matric common cathodeOperating voltage: 5VDimension: 12.8 x 12.8 x 1.3cmFixing screws with 64 holes with a diameter 3mmModule with input and output interfaces、support for cascading multiple modulesHow to use:The left side of the module is the input port、 the right is an output portWhen the control of a single module、 simply input port connected to CPUWhen you want to control several modules、 just the input port of the first module connect to the CPU、 then the output port connect to the input port of the second module、 the output port of the second module connect to the input port of the third module、 and so on...Take 51 Microcontrollers as an example:VCC !#!amp!*!rarr; 5VGND !#!amp!*!rarr; GNDDIN !#!amp!*!rarr; P2.2CS !#!amp!*!rarr; P2.1CLK !#!amp!*!rarr; P2.0Package includes:1 x MAX7219 4 in 1 module