MAX7219 is an integrated serial input/output common cathode display driver. It connects microprocessors to 8-digit 7-segment LED displays, as well as bar graph displays or 64 individual LEDs. The device includes an on-chip B-type BCD encoder, a multiplex scan circuit, segment-word drivers, and an 8x8 static RAM for storing data. There is only one external register for setting the segment current of each LED.
A convenient 4-wire serial interface allows connection to general-purpose microprocessors. Each data can be addressed without rewriting all displays during updates. MAX7219 also allows users to choose whether to encode or not encode each data.
The entire device includes a low-power shutdown mode with 150μA, analog and digital brightness control, a scan limit register that allows users to display 1-8 digits of data, and a test mode where all LEDs light up.
Module Parameters:
A single module can drive an 8x8 common cathode dot matrix.
Module operating voltage: 5V.
Module dimensions: 3.2 cm (length) x 3.2 cm (width) x 1.3 cm (height).
Features 4 screw holes with a diameter of 3mm.
The module has input and output interfaces, supporting cascading of multiple modules.
Wiring Instructions:
The left side of the module is the input port, and the right side is the output port.
When controlling a single module, simply connect the input port to the CPU.
When cascading multiple modules, connect the input port of the first module to the CPU, the output port of the first module to the input port of the second module, the output port of the second module to the input port of the third module, and so on.
Example with 51 Microcontroller:
VCC → 5V
GND → GND
DIN → P2.0
CS → P2.1
CLK → P2.2