HiLetgo 2pcs MAX7219 Dot matrix module DIY kit MCU control Display module for Arduino A single module can drive an 8 * 8 common cathode lattice Only one external register is used to set the segment current of each LED Module with input and output interfaces, supports multiple modules cascade MAX7219 is an integrated serial input / output common cathode display driver A convenient four line serial interface can connect all the general-purpose microprocessors