From 1be6e533165cb773979739c203b745df24ff1ecf Mon Sep 17 00:00:00 2001 From: Caleb Jamison Date: Tue, 9 May 2023 17:05:39 -0400 Subject: [PATCH 1/2] Pin fix, improve fifo handling --- examples/rp/src/bin/{ws2812-pio.rs => pio_ws2812.rs} | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) rename examples/rp/src/bin/{ws2812-pio.rs => pio_ws2812.rs} (95%) diff --git a/examples/rp/src/bin/ws2812-pio.rs b/examples/rp/src/bin/pio_ws2812.rs similarity index 95% rename from examples/rp/src/bin/ws2812-pio.rs rename to examples/rp/src/bin/pio_ws2812.rs index f4c2d631..4915c7e9 100644 --- a/examples/rp/src/bin/ws2812-pio.rs +++ b/examples/rp/src/bin/pio_ws2812.rs @@ -48,6 +48,8 @@ impl<'d, P: Instance, const S: usize> Ws2812<'d, P, S> { // Pin config let out_pin = pio.make_pio_pin(pin); + cfg.set_out_pins(&[&out_pin]); + cfg.set_set_pins(&[&out_pin]); let relocated = RelocatedProgram::new(&prg); cfg.use_program(&pio.load_program(&relocated), &[&out_pin]); @@ -76,7 +78,9 @@ impl<'d, P: Instance, const S: usize> Ws2812<'d, P, S> { pub async fn write(&mut self, colors: &[RGB8]) { for color in colors { let word = (u32::from(color.g) << 24) | (u32::from(color.r) << 16) | (u32::from(color.b) << 8); - self.sm.tx().wait_push(word).await; + if !self.sm.tx().try_push(word) { + self.sm.tx().wait_push(word).await; + } } } } From 1ebb742fbf9839ab393c038f320003a9346d37ff Mon Sep 17 00:00:00 2001 From: Caleb Jamison Date: Fri, 19 May 2023 16:48:47 -0400 Subject: [PATCH 2/2] Switch to DMA, use new clocks, don't take ownership of pio common --- examples/rp/src/bin/pio_ws2812.rs | 44 ++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 13 deletions(-) diff --git a/examples/rp/src/bin/pio_ws2812.rs b/examples/rp/src/bin/pio_ws2812.rs index 4915c7e9..26422421 100644 --- a/examples/rp/src/bin/pio_ws2812.rs +++ b/examples/rp/src/bin/pio_ws2812.rs @@ -4,18 +4,30 @@ use defmt::*; use embassy_executor::Spawner; +use embassy_rp::dma::{AnyChannel, Channel}; use embassy_rp::pio::{Common, Config, FifoJoin, Instance, Pio, PioPin, ShiftConfig, ShiftDirection, StateMachine}; use embassy_rp::relocate::RelocatedProgram; +use embassy_rp::{clocks, into_ref, Peripheral, PeripheralRef}; use embassy_time::{Duration, Timer}; +use fixed::types::U24F8; use fixed_macro::fixed; use smart_leds::RGB8; use {defmt_rtt as _, panic_probe as _}; -pub struct Ws2812<'d, P: Instance, const S: usize> { + +pub struct Ws2812<'d, P: Instance, const S: usize, const N: usize> { + dma: PeripheralRef<'d, AnyChannel>, sm: StateMachine<'d, P, S>, } -impl<'d, P: Instance, const S: usize> Ws2812<'d, P, S> { - pub fn new(mut pio: Common<'d, P>, mut sm: StateMachine<'d, P, S>, pin: impl PioPin) -> Self { +impl<'d, P: Instance, const S: usize, const N: usize> Ws2812<'d, P, S, N> { + pub fn new( + pio: &mut Common<'d, P>, + mut sm: StateMachine<'d, P, S>, + dma: impl Peripheral

+ 'd, + pin: impl PioPin, + ) -> Self { + into_ref!(dma); + // Setup sm0 // prepare the PIO program @@ -56,7 +68,7 @@ impl<'d, P: Instance, const S: usize> Ws2812<'d, P, S> { // Clock config, measured in kHz to avoid overflows // TODO CLOCK_FREQ should come from embassy_rp - let clock_freq = fixed!(125_000: U24F8); + let clock_freq = U24F8::from_num(clocks::clk_sys_freq() / 1000); let ws2812_freq = fixed!(800: U24F8); let bit_freq = ws2812_freq * CYCLES_PER_BIT; cfg.clock_divider = clock_freq / bit_freq; @@ -72,16 +84,22 @@ impl<'d, P: Instance, const S: usize> Ws2812<'d, P, S> { sm.set_config(&cfg); sm.set_enable(true); - Self { sm } + Self { + dma: dma.map_into(), + sm, + } } - pub async fn write(&mut self, colors: &[RGB8]) { - for color in colors { - let word = (u32::from(color.g) << 24) | (u32::from(color.r) << 16) | (u32::from(color.b) << 8); - if !self.sm.tx().try_push(word) { - self.sm.tx().wait_push(word).await; - } + pub async fn write(&mut self, colors: &[RGB8; 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); + words[i] = word; } + + // DMA transfer + self.sm.tx().dma_push(self.dma.reborrow(), &words).await; } } @@ -105,7 +123,7 @@ async fn main(_spawner: Spawner) { info!("Start"); let p = embassy_rp::init(Default::default()); - let Pio { common, sm0, .. } = Pio::new(p.PIO0); + let Pio { mut common, sm0, .. } = Pio::new(p.PIO0); // This is the number of leds in the string. Helpfully, the sparkfun thing plus and adafruit // feather boards for the 2040 both have one built in. @@ -114,7 +132,7 @@ async fn main(_spawner: Spawner) { // For the thing plus, use pin 8 // For the feather, use pin 16 - let mut ws2812 = Ws2812::new(common, sm0, p.PIN_8); + let mut ws2812 = Ws2812::new(&mut common, sm0, p.DMA_CH0, p.PIN_16); // Loop forever making RGB values and pushing them out to the WS2812. loop {