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Merge pull request #4236 from MatrixSenpai/ws2812-rgbw-pio

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Support RGBW on PioWs2812
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Ulf Lilleengen 2025-05-27 06:24:03 +00:00 committed by GitHub
commit f73a390bc8
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1 changed files with 68 additions and 2 deletions
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70
embassy-rp/src/pio_programs/ws2812.rs
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@ -2,7 +2,7 @@
use embassy_time::Timer;
use fixed::types::U24F8;
use smart_leds::RGB8;
use smart_leds::{RGB8, RGBW};
use crate::clocks::clk_sys_freq;
use crate::dma::{AnyChannel, Channel};
@ -50,7 +50,7 @@ impl<'a, PIO: Instance> PioWs2812Program<'a, PIO> {
}
}
/// Pio backed ws2812 driver
/// Pio backed RGB ws2812 driver
/// Const N is the number of ws2812 leds attached to this pin
pub struct PioWs2812<'d, P: Instance, const S: usize, const N: usize> {
dma: Peri<'d, AnyChannel>,
@ -111,3 +111,69 @@ impl<'d, P: Instance, const S: usize, const N: usize> PioWs2812<'d, P, S, N> {
Timer::after_micros(55).await;
}
}
/// Pio backed RGBW ws2812 driver
/// This version is intended for ws2812 leds with 4 addressable lights
/// Const N is the number of ws2812 leds attached to this pin
pub struct RgbwPioWs2812<'d, P: Instance, const S: usize, const N: usize> {
dma: Peri<'d, AnyChannel>,
sm: StateMachine<'d, P, S>,
}
impl<'d, P: Instance, const S: usize, const N: usize> RgbwPioWs2812<'d, P, S, N> {
/// Configure a pio state machine to use the loaded ws2812 program.
pub fn new(
pio: &mut Common<'d, P>,
mut sm: StateMachine<'d, P, S>,
dma: Peri<'d, impl Channel>,
pin: Peri<'d, impl PioPin>,
program: &PioWs2812Program<'d, P>,
) -> Self {
// Setup sm0
let mut cfg = Config::default();
// Pin config
let out_pin = pio.make_pio_pin(pin);
cfg.set_out_pins(&[&out_pin]);
cfg.set_set_pins(&[&out_pin]);
cfg.use_program(&program.prg, &[&out_pin]);
// Clock config, measured in kHz to avoid overflows
let clock_freq = U24F8::from_num(clk_sys_freq() / 1000);
let ws2812_freq = U24F8::from_num(800);
let bit_freq = ws2812_freq * CYCLES_PER_BIT;
cfg.clock_divider = clock_freq / bit_freq;
// FIFO config
cfg.fifo_join = FifoJoin::TxOnly;
cfg.shift_out = ShiftConfig {
auto_fill: true,
threshold: 32,
direction: ShiftDirection::Left,
};
sm.set_config(&cfg);
sm.set_enable(true);
Self { dma: dma.into(), sm }
}
/// Write a buffer of [smart_leds::RGBW] to the ws2812 string
pub async fn write(&mut self, colors: &[RGBW<u8>; N]) {
// Precompute the word bytes from the colors
let mut words = [0u32; N];
for i in 0..N {
let word = (u32::from(colors[i].g) << 24)
| (u32::from(colors[i].r) << 16)
| (u32::from(colors[i].b) << 8)
| u32::from(colors[i].a.0);
words[i] = word;
}
// DMA transfer
self.sm.tx().dma_push(self.dma.reborrow(), &words, false).await;
Timer::after_micros(55).await;
}
}