MAX7219

Connects over

SPI

Made by

Maxim Integrated

Datasheet

datasheets.maximintegrated.com

Use it

hardware {
    device max7219: MAX7219(cs: 16)
}

every 1s {
    max7219.set_row(1, 1)
}

The MAX7219 goes on the SPI bus; give it its cs pin as an argument.

Methods

• max7219.set_row(row: int, data: int)

  Set matrix row

• max7219.set_intensity(level: int)

  Brightness 0-15

• max7219.clear()

  Clear all

• max7219.set_digit(pos: int, value: int, dp: int)

  Set 7-seg digit

Wiring

Specifications

Voltage

4.0V – 5.5V (logic + LED supply)

Current

330 mA peak (all LEDs on full brightness)

Outputs

8 digits × 7-segment, or 8×8 LED matrix

Brightness steps

16

Interface speed

SPI up to 10 MHz

Tips

• Daisy-chain by feeding each chip's DOUT into the next chip's DIN — same CS for all.
• ISET resistor between ISET pin and VCC sets segment current — use 22kΩ for normal LEDs, 10kΩ pushes brighter.
• MAX7219 sources 5V to segments — works for 2V LEDs through built-in driver; not for 12V LEDs.

Alternatives worth knowing:

• HT16K33: I²C alternative — fewer pins on the MCU side.