LED matrix demo

Cargo.lock

@@ -766,6 +766,7 @@ dependencies = [
  "heapless",
  "mipidsi",
  "panic-probe",
+ "rgb",
 ]
 
 [[package]]
@@ -1083,6 +1084,9 @@ name = "rgb"
 version = "0.8.52"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c6a884d2998352bb4daf0183589aec883f16a6da1f4dde84d8e2e9a5409a1ce"
+dependencies = [
+ "bytemuck",
+]
 
 [[package]]
 name = "rp-pac"

firmware/Cargo.toml

@@ -47,3 +47,4 @@ mipidsi = "0.9.0"
 embedded-hal-bus = "0.3.0"
 embassy-futures = "0.1.2"
 heapless = "0.8.0"
+rgb = "0.8.52"

firmware/src/main.rs

@@ -1,36 +1,61 @@
 #![no_std]
 #![no_main]
 
+use core::convert::Infallible;
+
 use embassy_executor::Spawner;
 use embassy_futures::select::select_array;
+use embassy_rp::bind_interrupts;
 use embassy_rp::gpio::{Input, Level, Output, Pull};
+use embassy_rp::peripherals::PIO0;
+use embassy_rp::pio::Pio;
+use embassy_rp::pio_programs::ws2812::{PioWs2812, PioWs2812Program};
 use embassy_rp::pwm::{self, Pwm};
 use embassy_rp::rom_data::reset_to_usb_boot;
 use embassy_time::Delay;
+use embedded_graphics::primitives::{PrimitiveStyleBuilder, Rectangle};
 use embedded_hal_bus::spi::ExclusiveDevice;
 use heapless::String;
 use mipidsi::interface::SpiInterface;
 use mipidsi::models::ST7789;
 use mipidsi::options::Orientation;
+use rgb::RGB8;
+
 use {defmt_rtt as _, panic_probe as _};
 
-use embassy_rp::spi;
-use embassy_rp::spi::{Blocking, Spi};
+use embassy_rp::spi::{self, Blocking, Spi};
 use embedded_graphics::image::{Image, ImageRawLE};
 use embedded_graphics::mono_font::MonoTextStyle;
 use embedded_graphics::mono_font::ascii::FONT_10X20;
-use embedded_graphics::pixelcolor::Rgb565;
+use embedded_graphics::pixelcolor::{Rgb565, Rgb888};
 use embedded_graphics::prelude::*;
 use embedded_graphics::text::Text;
 
 use {defmt_rtt as _, panic_probe as _};
 
+bind_interrupts!(struct Irqs {
+    PIO0_IRQ_0 => embassy_rp::pio::InterruptHandler<PIO0>;
+});
+
 const DISPLAY_FREQ: u32 = 64_000_000;
 
 #[embassy_executor::main]
 async fn main(spawner: Spawner) -> ! {
     let p = embassy_rp::init(Default::default());
 
+    // Setup buttons
+    let _btn_a = Input::new(p.PIN_12, Pull::Up);
+    let _btn_b = Input::new(p.PIN_13, Pull::Up);
+    // let _btn_x = Input::new(p.PIN_14, Pull::Up);
+    let btn_y = Input::new(p.PIN_15, Pull::Up);
+
+    let mut btn_f1 = Input::new(p.PIN_11, Pull::Up);
+    let mut btn_f2 = Input::new(p.PIN_14, Pull::Up);
+    let mut btn_f3 = Input::new(p.PIN_9, Pull::Up);
+    let mut btn_f4 = Input::new(p.PIN_3, Pull::Up);
+
+    spawner.spawn(dfu_button(btn_y)).ok();
+
     // display SPI
 
     let mut display_buffer = [0u8; 512];
@@ -87,16 +112,33 @@ async fn main(spawner: Spawner) -> ! {
         b_pwm.set_config(&b_config);
     };
 
-    // Setup buttons
-    let _btn_a = Input::new(p.PIN_12, Pull::Up);
-    let _btn_b = Input::new(p.PIN_13, Pull::Up);
-    // let _btn_x = Input::new(p.PIN_14, Pull::Up);
-    let btn_y = Input::new(p.PIN_15, Pull::Up);
+    let mut led_pio = Pio::new(p.PIO0, Irqs);
+    let led_program = PioWs2812Program::new(&mut led_pio.common);
 
-    let mut btn_f1 = Input::new(p.PIN_11, Pull::Up);
-    let mut btn_f2 = Input::new(p.PIN_14, Pull::Up);
-    let mut btn_f3 = Input::new(p.PIN_9, Pull::Up);
-    let mut btn_f4 = Input::new(p.PIN_3, Pull::Up);
+    let mut led_surface = LedMatrix::new(
+        Serpentine {
+            size: Size::new(40, 8),
+        },
+        PioWs2812::new(
+            &mut led_pio.common,
+            led_pio.sm0,
+            p.DMA_CH0,
+            p.PIN_10,
+            &led_program,
+        ),
+    );
+    led_surface.clear(Rgb888::BLACK).ok();
+    Rectangle::new(Point::zero(), led_surface.size())
+        .into_styled(
+            PrimitiveStyleBuilder::new()
+                .stroke_color(Rgb888::RED)
+                .stroke_width(1)
+                .fill_color(Rgb888::CSS_DARK_BLUE)
+                .build(),
+        )
+        .draw(&mut led_surface)
+        .ok();
+    led_surface.sync().await;
 
     let mut render = |f_keys: [bool; 4]| {
         display.clear(Rgb565::BLACK).ok();
@@ -115,8 +157,6 @@ async fn main(spawner: Spawner) -> ! {
 
     let mut last_state = None;
 
-    spawner.spawn(dfu_button(btn_y)).ok();
-
     loop {
         let state = [
             btn_f1.is_low(),
@@ -144,3 +184,71 @@ async fn dfu_button(mut btn_y: Input<'static>) {
     btn_y.wait_for_falling_edge().await;
     reset_to_usb_boot(0, 0);
 }
+
+struct Serpentine {
+    size: Size,
+}
+
+impl Serpentine {
+    fn map(&self, mut p: Point) -> Option<usize> {
+        if p.x < 0 || p.x as u32 >= self.size.width || p.y < 0 || p.y as u32 >= self.size.height {
+            return None;
+        }
+
+        if p.y % 2 == 0 {
+            p.x = self.size.width as i32 - 1 - p.x;
+        }
+
+        Some(p.y as usize * self.size.width as usize + p.x as usize)
+    }
+}
+
+struct LedMatrix<'d> {
+    buffer: [RGB8; 320],
+    layout: Serpentine,
+    pio: PioWs2812<'d, PIO0, 0, 320>,
+}
+
+impl<'d> LedMatrix<'d> {
+    fn new(layout: Serpentine, pio: PioWs2812<'d, PIO0, 0, 320>) -> Self {
+        Self {
+            buffer: [RGB8::default(); 320],
+            layout,
+            pio,
+        }
+    }
+
+    async fn sync(&mut self) {
+        self.pio.write(&self.buffer).await;
+    }
+}
+
+impl<'d> DrawTarget for LedMatrix<'d> {
+    type Color = Rgb888;
+
+    type Error = Infallible;
+
+    fn draw_iter<I>(&mut self, pixels: I) -> Result<(), Self::Error>
+    where
+        I: IntoIterator<Item = Pixel<Self::Color>>,
+    {
+        for Pixel(point, color) in pixels {
+            if let Some(x) = self.layout.map(point).and_then(|i| self.buffer.get_mut(i)) {
+                // Map to 0-64 for brightness limiting
+                *x = RGB8::new(
+                    color.r().div_ceil(4),
+                    color.g().div_ceil(4),
+                    color.b().div_ceil(4),
+                );
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl<'d> OriginDimensions for LedMatrix<'d> {
+    fn size(&self) -> Size {
+        self.layout.size
+    }
+}