This crate provides a platform agnostic driver for the MAX7219 LED Driver IC.

This driver was built using the embedded-hal traits.

Usage

Single MAX7219 Device

An updated version of the library should be available on crates.io. Add the following to your Cargo.toml to get is a dependency.

[dependencies]
max7219-driver = "*"

Instantiating

Create an instance of the driver with the new method, by passing SPI and Output pin instances.

use max7219-driver::MAX7219;
let spi = // SPI instantiation code
let cs = // Output pin instantiation code
let mut max7219 = MAX7219::new(spi, cs).unwrap();

Initializing

Initialize the driver instance with the init_display method. A boolean needs to be specified to indicate whether to clear the display after init or not.

 max7219.init_display(true);

Cascading Multiple MAX7219 Devices

If you are cascading multiple devices that are driving 8x8 LED Dot Matrices instead use the MAX7219LedMat driver as follows:

Instantiating

use max7219-driver::MAX7219LedMat;
let spi = // SPI instantiation code
let cs = // Output pin instantiation code
let mut max7219: MAX7219LedMat<_, _, BUFLEN, COUNT> = MAX7219LedMat::new(spi, cs).unwrap();

BUFLEN should be replaced with value equivalent to the total number of pixels/LED in the cascaded displays and COUNT with the number of displays

Example:

If four displays are cascaded then BUFLEN should be replaced with 256 (= 8 x 8 x 4) and COUNT replaced with 4 resulting in

let mut max7219: MAX7219LedMat<_, _, 256, 4> = MAX7219LedMat::new(spi, cs).unwrap();

Initializing

Exactly the same as earlier, the new driver takes care of initializing all the cscaded displays.

max7219.init_display(true);