mirror of
https://github.com/italicsjenga/rp-hal-boards.git
synced 2024-12-24 13:11:30 +11:00
223 lines
6.8 KiB
Rust
223 lines
6.8 KiB
Rust
//! # Pico WS2812 RGB LED Example
|
|
//!
|
|
//! Drives 3 WS2812 LEDs connected directly to the Raspberry Pi Pico.
|
|
//! This assumes you drive the Raspberry Pi Pico via USB power, so that VBUS
|
|
//! delivers the 5V and at least enough amperes to drive the LEDs.
|
|
//!
|
|
//! For a more large scale and longer strips you should use an extra power
|
|
//! supply for the LED strip (or know what you are doing ;-) ).
|
|
//!
|
|
//! The example also comes with an utility function to calculate the colors
|
|
//! from HSV color space. It also limits the brightness a bit to save a
|
|
//! few milliamperes - be careful if you increase the strip length you will
|
|
//! quickly get into power consumption of multiple amperes.
|
|
//!
|
|
//! The example assumes you connected the data input to pin 6 of the
|
|
//! Raspberry Pi Pico, which is GPIO4 of the rp2040. Here is a circuit
|
|
//! diagram that shows the assumed setup:
|
|
//!
|
|
//! ```text
|
|
//! _______________ /----------------------\
|
|
//! |+5V /---\ +5V|----/ _|USB|_ |
|
|
//! |DO <-|LED|<- DI|-\ |1 R 40|-VBUS-/
|
|
//! |GND \---/ GND|--+---\ |2 P 39|
|
|
//! """"""""""""""" | \-GND-|3 38|
|
|
//! | |4 P 37|
|
|
//! | |5 I 36|
|
|
//! \------GP4-|6 C |
|
|
//! |7 O |
|
|
//! | |
|
|
//! .........
|
|
//! |20 21|
|
|
//! """""""
|
|
//! Symbols:
|
|
//! - (+) crossing lines, not connected
|
|
//! - (o) connected lines
|
|
//! ```
|
|
//!
|
|
//! See the `Cargo.toml` file for Copyright and license details.
|
|
|
|
#![no_std]
|
|
#![no_main]
|
|
|
|
// The macro for our start-up function
|
|
use cortex_m_rt::entry;
|
|
|
|
// Ensure we halt the program on panic (if we don't mention this crate it won't
|
|
// be linked)
|
|
use panic_halt as _;
|
|
|
|
// Pull in any important traits
|
|
use rp_pico::hal::prelude::*;
|
|
|
|
// Embed the `Hz` function/trait:
|
|
use embedded_time::rate::*;
|
|
|
|
// A shorter alias for the Peripheral Access Crate, which provides low-level
|
|
// register access
|
|
use rp_pico::hal::pac;
|
|
|
|
// Import the Timer for Ws2812:
|
|
use rp_pico::hal::timer::Timer;
|
|
|
|
// A shorter alias for the Hardware Abstraction Layer, which provides
|
|
// higher-level drivers.
|
|
use rp_pico::hal;
|
|
|
|
// PIOExt for the split() method that is needed to bring
|
|
// PIO0 into useable form for Ws2812:
|
|
use rp_pico::hal::pio::PIOExt;
|
|
|
|
// Import useful traits to handle the ws2812 LEDs:
|
|
use smart_leds::{brightness, SmartLedsWrite, RGB8};
|
|
|
|
// Import the actual crate to handle the Ws2812 protocol:
|
|
use ws2812_pio::Ws2812;
|
|
|
|
// Currently 3 consecutive LEDs are driven by this example
|
|
// to keep the power draw compatible with USB:
|
|
const STRIP_LEN: usize = 3;
|
|
|
|
#[entry]
|
|
fn main() -> ! {
|
|
// Grab our singleton objects
|
|
let mut pac = pac::Peripherals::take().unwrap();
|
|
let core = pac::CorePeripherals::take().unwrap();
|
|
|
|
// Set up the watchdog driver - needed by the clock setup code
|
|
let mut watchdog = hal::Watchdog::new(pac.WATCHDOG);
|
|
|
|
// Configure the clocks
|
|
//
|
|
// The default is to generate a 125 MHz system clock
|
|
let clocks = hal::clocks::init_clocks_and_plls(
|
|
rp_pico::XOSC_CRYSTAL_FREQ,
|
|
pac.XOSC,
|
|
pac.CLOCKS,
|
|
pac.PLL_SYS,
|
|
pac.PLL_USB,
|
|
&mut pac.RESETS,
|
|
&mut watchdog,
|
|
)
|
|
.ok()
|
|
.unwrap();
|
|
|
|
// The single-cycle I/O block controls our GPIO pins
|
|
let sio = hal::Sio::new(pac.SIO);
|
|
|
|
// Set the pins up according to their function on this particular board
|
|
let pins = rp_pico::Pins::new(
|
|
pac.IO_BANK0,
|
|
pac.PADS_BANK0,
|
|
sio.gpio_bank0,
|
|
&mut pac.RESETS,
|
|
);
|
|
|
|
// Setup a delay for the LED blink signals:
|
|
let mut frame_delay =
|
|
cortex_m::delay::Delay::new(core.SYST, clocks.system_clock.freq().integer());
|
|
|
|
// Import the `sin` function for a smooth hue animation from the
|
|
// Pico rp2040 ROM:
|
|
let sin = rp_pico::hal::rom_data::float_funcs::fsin::ptr();
|
|
|
|
// Create a count down timer for the Ws2812 instance:
|
|
let timer = Timer::new(pac.TIMER, &mut pac.RESETS);
|
|
|
|
// Split the PIO state machine 0 into individual objects, so that
|
|
// Ws2812 can use it:
|
|
let (mut pio, sm0, _, _, _) = pac.PIO0.split(&mut pac.RESETS);
|
|
|
|
// Instanciate a Ws2812 LED strip:
|
|
let mut ws = Ws2812::new(
|
|
// Use pin 6 on the Raspberry Pi Pico (which is GPIO4 of the rp2040 chip)
|
|
// for the LED data output:
|
|
pins.gpio4.into_mode(),
|
|
&mut pio,
|
|
sm0,
|
|
clocks.peripheral_clock.freq(),
|
|
timer.count_down(),
|
|
);
|
|
|
|
let mut leds: [RGB8; STRIP_LEN] = [(0, 0, 0).into(); STRIP_LEN];
|
|
let mut t = 0.0;
|
|
|
|
// Bring down the overall brightness of the strip to not blow
|
|
// the USB power supply: every LED draws ~60mA, RGB means 3 LEDs per
|
|
// ws2812 LED, for 3 LEDs that would be: 3 * 3 * 60mA, which is
|
|
// already 540mA for just 3 white LEDs!
|
|
let strip_brightness = 64u8; // Limit brightness to 64/256
|
|
|
|
// Slow down timer by this factor (0.1 will result in 10 seconds):
|
|
let animation_speed = 0.1;
|
|
|
|
loop {
|
|
for (i, led) in leds.iter_mut().enumerate() {
|
|
// An offset to give 3 consecutive LEDs a different color:
|
|
let hue_offs = match i % 3 {
|
|
1 => 0.25,
|
|
2 => 0.5,
|
|
_ => 0.0,
|
|
};
|
|
|
|
let sin_11 = sin((t + hue_offs) * 2.0 * core::f32::consts::PI);
|
|
// Bring -1..1 sine range to 0..1 range:
|
|
let sin_01 = (sin_11 + 1.0) * 0.5;
|
|
|
|
let hue = 360.0 * sin_01;
|
|
let sat = 1.0;
|
|
let val = 1.0;
|
|
|
|
let rgb = hsv2rgb_u8(hue, sat, val);
|
|
*led = rgb.into();
|
|
}
|
|
|
|
// Here the magic happens and the `leds` buffer is written to the
|
|
// ws2812 LEDs:
|
|
ws.write(brightness(leds.iter().copied(), strip_brightness))
|
|
.unwrap();
|
|
|
|
// Wait a bit until calculating the next frame:
|
|
frame_delay.delay_ms(16); // ~60 FPS
|
|
|
|
// Increase the time counter variable and make sure it
|
|
// stays inbetween 0.0 to 1.0 range:
|
|
t += (16.0 / 1000.0) * animation_speed;
|
|
while t > 1.0 {
|
|
t -= 1.0;
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn hsv2rgb(hue: f32, sat: f32, val: f32) -> (f32, f32, f32) {
|
|
let c = val * sat;
|
|
let v = (hue / 60.0) % 2.0 - 1.0;
|
|
let v = if v < 0.0 { -v } else { v };
|
|
let x = c * (1.0 - v);
|
|
let m = val - c;
|
|
let (r, g, b) = if hue < 60.0 {
|
|
(c, x, 0.0)
|
|
} else if hue < 120.0 {
|
|
(x, c, 0.0)
|
|
} else if hue < 180.0 {
|
|
(0.0, c, x)
|
|
} else if hue < 240.0 {
|
|
(0.0, x, c)
|
|
} else if hue < 300.0 {
|
|
(x, 0.0, c)
|
|
} else {
|
|
(c, 0.0, x)
|
|
};
|
|
(r + m, g + m, b + m)
|
|
}
|
|
|
|
pub fn hsv2rgb_u8(h: f32, s: f32, v: f32) -> (u8, u8, u8) {
|
|
let r = hsv2rgb(h, s, v);
|
|
|
|
(
|
|
(r.0 * 255.0) as u8,
|
|
(r.1 * 255.0) as u8,
|
|
(r.2 * 255.0) as u8,
|
|
)
|
|
}
|