1. The left side of the module is the input port, and the right is the output port.
2. Control of a single module, the input port only needs to receive CPU.
3. The more a module cascade and input end of the first module is connected with the CPU and input end of the input end of the output end is connected to the second module, output terminal of the second module connected with the three modules, and so on.
For example 51 SCM
1 x MAX7219 Dot Matrix Module
1 x 5pin Dupont Cable