MAX7219/MAX7221 is an integrated serial input/output common cathode display driver, which connects microprocessors.
With 8-digit 7-segment digital LED display, you can also connect a bar chart display or 64 separate LEDs. It includes one
B-type BCD encoder on chip, multi-channel scanning circuit, segment driver, and 8*8 static RAM for storage
Store each data. Only one external register is used to set the segment current of each LED. MAX7221 and SPI and QSPI
MICROWIRE is compatible, and it has a segment drive that limits the rotating current to reduce EMI.
A convenient four-wire serial interface can connect all general purpose microprocessors. Each data can be addressable without updating