rp-hal-boards/boards/pro_micro_rp2040/examples/pro_micro_rainbow.rs
2021-09-27 18:42:36 +01:00

117 lines
3 KiB
Rust

//! # Rainbow Example for the Pro Micro RP2040
//!
//! Runs a rainbow-effect colour wheel on the on-board LED.
//!
//! Uses the `ws2812_pio` driver to control the LED, which in turns uses the
//! RP2040's PIO block.
#![no_std]
#![no_main]
use core::iter::once;
use cortex_m_rt::entry;
use embedded_hal::timer::CountDown;
use embedded_time::duration::Extensions;
use panic_halt as _;
use pro_micro_rp2040::{
hal::{
clocks::{init_clocks_and_plls, Clock},
gpio::{FunctionPio0, Pin},
pac,
sio::Sio,
timer::Timer,
watchdog::Watchdog,
},
XOSC_CRYSTAL_FREQ,
};
use smart_leds::{brightness, SmartLedsWrite, RGB8};
use ws2812_pio::Ws2812;
//// The linker will place this boot block at the start of our program image.
/// We need this to help the ROM bootloader get our code up and running.
#[link_section = ".boot2"]
#[used]
pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER;
/// Entry point to our bare-metal application.
///
/// The `#[entry]` macro ensures the Cortex-M start-up code calls this
/// function as soon as all global variables are initialised.
///
/// The function configures the RP2040 peripherals, then the LED, then runs
/// the colour wheel in an infinite loop.
#[entry]
fn main() -> ! {
// Configure the RP2040 peripherals
let mut pac = pac::Peripherals::take().unwrap();
let mut watchdog = Watchdog::new(pac.WATCHDOG);
let clocks = init_clocks_and_plls(
XOSC_CRYSTAL_FREQ,
pac.XOSC,
pac.CLOCKS,
pac.PLL_SYS,
pac.PLL_USB,
&mut pac.RESETS,
&mut watchdog,
)
.ok()
.unwrap();
let sio = Sio::new(pac.SIO);
let pins = pro_micro_rp2040::Pins::new(
pac.IO_BANK0,
pac.PADS_BANK0,
sio.gpio_bank0,
&mut pac.RESETS,
);
let _led: Pin<_, FunctionPio0> = pins.led.into_mode();
let timer = Timer::new(pac.TIMER);
let mut delay = timer.count_down();
// Configure the addressable LED
let mut ws = Ws2812::new(
25,
pac.PIO0,
&mut pac.RESETS,
clocks.peripheral_clock.freq(),
timer.count_down(),
);
// Infinite colour wheel loop
let mut n: u8 = 128;
loop {
ws.write(brightness(once(wheel(n)), 32)).unwrap();
n = n.wrapping_add(1);
delay.start(25.milliseconds());
let _ = nb::block!(delay.wait());
}
}
/// Convert a number from `0..=255` to an RGB color triplet.
///
/// The colours are a transition from red, to green, to blue and back to red.
fn wheel(mut wheel_pos: u8) -> RGB8 {
wheel_pos = 255 - wheel_pos;
if wheel_pos < 85 {
// No green in this sector - red and blue only
(255 - (wheel_pos * 3), 0, wheel_pos * 3).into()
} else if wheel_pos < 170 {
// No red in this sector - green and blue only
wheel_pos -= 85;
(0, wheel_pos * 3, 255 - (wheel_pos * 3)).into()
} else {
// No blue in this sector - red and green only
wheel_pos -= 170;
(wheel_pos * 3, 255 - (wheel_pos * 3), 0).into()
}
}