SPECIFICATIONS

 MAX7219 is a kind of integrated serial input/output common cathode display drive, it connects the microprocessor with eight digit seven segment digital LED display, also can connect the line graph display or 64 independent leds. It includes a piece of type B BCD coder, multiplexing scanning circuit, drive period of word, but also a 8 * 8 static RAM is used to store each data. Only an external registers used to set the period of current of each LED.

 
A convenient four wire serial interface can join all general microprocessor. Each data can be addressed in the update does not need to rewrite all the display. MAX7219 also allows users to each data selection code or code.
The device contains A 150 mu A low-power shutdown mode, analog and digital brightness control, A scan limit register allows the user to display 1-8 bits of data, there is also A let all LED detection mode.

PCB four corners with copper screw fixation, which can effectively prevent short circuit accident happens! 

Four digital tube is 0.36 inch one common cathode digital tube
 
This module is compatible with 5 V / 3.3 V microcontroller (51 / AVR STM32...)
 
Wiring instructions (in order to provide the program, for example, you can pick any IO mouth, modify ports defined in the program) :
 
The VCC - 5 v
 
GND to GND
 
DIN - P00
 
CS - P01
 
The CLK - P02
 
Note:
 
1. The VCC and GND don't pick up the, so as not to burn out the chip
 
2.51 SCM P0 port need to pull resistance, if your microcontroller could not pull resistance, can be cable to other ports