Overview:
The MAX7219 is an integrated serial input / output common-cathode display driver, it is connected to a microprocessor with 8-digit 7-segment digital LED display can also be connected to the bar graph display or 64 separate LED. On B BCD encoder including an on-chip, multi-channel scanning loop word drive, but also an 8 x 8 static RAM is used to store each data. Only one external register is used to set the current of each LED segment.
A convenient four-wire serial interface can connect all general-purpose microprocessor. Each data can be addressed in the update does not need to rewrite all the display. MAX7219 also allows the user to select on each data coding or non-coding.
The entire device contains a 150|IA low-power shutdown mode, analog and digital brightness control, a scan-limit register allows the user to display the 1-8 bits of data, as well as a let all LED light detection mode.
Feature:
10MHz Serial Interface
Individual LED Segment Control
Decode/No-Decode Digit Selection
150|IA Low Power Shutdown ( Data Retained )
Digital and Analog Brightness Control
Display Blanked on Power-Up
Drive Common Cathode LED Display
Slew Rate Limited Segment Drivers
Wiring instructions:
1. The module left side as an input port and the output port on the right
2. To control a single module, just connect the input port to the CPU
3. When cascading multiple modules, the input port of the first module connect to the CPU, the output port connect to the input port of the second one, and so on.
In the case of 51 MCU:
VCC ¡u 5V
GND ¡u GND
DIN ¡u P22
CS ¡u P21
CLK ¡u P20