A platform agnostic driver to interface with the MAX7219 (LED display driver)
- Powering on/off the MAX chip
- Basic commands for setting LEDs on/off.
- Chaining support (max 8 devices)
Here is a simple example for using the MAX7219 on a hifive1-revb device with e310x_hal:
#![no_std]
#![no_main]
extern crate panic_halt;
use riscv_rt::entry;
use hifive1::hal::prelude::*;
use hifive1::hal::e310x::Peripherals;
use max7219::*;
#[entry]
fn main() -> ! {
let p = Peripherals::take().unwrap();
// Configure clocks
hifive1::clock::configure(p.PRCI, p.AONCLK, 320.mhz().into());
// Configure SPI pins
let mut gpio = p.GPIO0.split();
let data = gpio.pin3.into_output(&mut gpio.output_en, &mut gpio.drive,
&mut gpio.out_xor, &mut gpio.iof_en);
let sck = gpio.pin5.into_output(&mut gpio.output_en, &mut gpio.drive,
&mut gpio.out_xor, &mut gpio.iof_en);
let cs = gpio.pin2.into_output(&mut gpio.output_en, &mut gpio.drive,
&mut gpio.out_xor, &mut gpio.iof_en);
let mut display = MAX7219::new(1, data, cs, sck).unwrap();
// make sure to wake the display up
display.power_on().unwrap();
// write given octet of ASCII characters with dots specified by 3rd param bits
display.write_str(0, b"pls help", 0b00100000).unwrap();
// set display intensity lower
display.set_intensity(0, 0x1).unwrap();
loop {}
}Original work by Maikel Wever. Adapted to latest embedded-hal and documented by Ales Katona.
Licensed under MIT license (LICENSE or http://opensource.org/licenses/MIT)