Add hello_rgb example to the esp-hal-smartled package

Author: jessebraham

.github/actions/check-package/action.yml

@@ -20,11 +20,11 @@ runs:
       shell: bash
       run: |
         cd ${{ inputs.package }}
-        cargo check --features=${{ inputs.soc }} --target=${{ inputs.target }}
+        cargo check --features=${{ inputs.soc }} --target=${{ inputs.target }} --examples
 
     # Build the package (Xtensa):
     - if: ${{ startsWith(inputs.target, 'xtensa') }}
       shell: bash
       run: |
         cd ${{ inputs.package }}
-        cargo check -Zbuild-std=core --features=${{ inputs.soc }} --target=${{ inputs.target }}
+        cargo check -Zbuild-std=core --features=${{ inputs.soc }} --target=${{ inputs.target }} --examples

esp-hal-smartled/.cargo/config.toml

@@ -0,0 +1,16 @@
+[target.'cfg(target_arch = "riscv32")']
+rustflags = [
+  "-C", "link-arg=-Tlinkall.x",
+  "-C", "force-frame-pointers",
+]
+
+[target.'cfg(target_arch = "xtensa")']
+rustflags = [
+  # GNU LD
+  "-C", "link-arg=-Wl,-Tlinkall.x",
+  "-C", "link-arg=-nostartfiles",
+
+  # LLD
+  # "-C", "link-arg=-Tlinkall.x",
+  # "-C", "linker=rust-lld",
+]

esp-hal-smartled/Cargo.toml

@@ -18,24 +18,36 @@ esp-hal           = "0.20.0"
 fugit             = "0.3.7"
 smart-leds-trait  = "0.3.0"
 
+[dev-dependencies]
+cfg-if = "1.0.0"
+esp-backtrace = { version = "0.14.1", features = [
+    "exception-handler",
+    "panic-handler",
+    "println",
+] }
+esp-println = "0.11.0"
+smart-leds = "0.4.0"
+
 [features]
 ## Implement `defmt::Format` on certain types.
 defmt = ["dep:defmt", "esp-hal/defmt"]
 
 #! ### Chip Support Feature Flags
 ## Target the ESP32.
-esp32 = ["esp-hal/esp32"]
+esp32 = ["esp-backtrace/esp32", "esp-hal/esp32", "esp-println/esp32"]
 ## Target the ESP32-C3.
-esp32c3 = ["esp-hal/esp32c3"]
+esp32c3 = ["esp-backtrace/esp32c3", "esp-hal/esp32c3", "esp-println/esp32c3"]
 ## Target the ESP32-C6.
-esp32c6 = ["esp-hal/esp32c6"]
+esp32c6 = ["esp-backtrace/esp32c6", "esp-hal/esp32c6", "esp-println/esp32c6"]
 ## Target the ESP32-H2.
-esp32h2 = ["esp-hal/esp32h2"]
+esp32h2 = ["esp-backtrace/esp32h2", "esp-hal/esp32h2", "esp-println/esp32h2"]
 ## Target the ESP32-S2.
-esp32s2 = ["esp-hal/esp32s2"]
+esp32s2 = ["esp-backtrace/esp32s2", "esp-hal/esp32s2", "esp-println/esp32s2"]
 ## Target the ESP32-S3.
-esp32s3 = ["esp-hal/esp32s3"]
+esp32s3 = ["esp-backtrace/esp32s3", "esp-hal/esp32s3", "esp-println/esp32s3"]
 
-# TODO: Remove patch prior to next release
+# TODO: Remove patches prior to next release
 [patch.crates-io]
-esp-hal = { git = "https://github.com/esp-rs/esp-hal", rev = "d44affc" }
+esp-backtrace = { git = "https://github.com/esp-rs/esp-hal", rev = "d44affc" }
+esp-hal       = { git = "https://github.com/esp-rs/esp-hal", rev = "d44affc" }
+esp-println   = { git = "https://github.com/esp-rs/esp-hal", rev = "d44affc" }

esp-hal-smartled/examples/hello_rgb.rs

@@ -0,0 +1,96 @@
+//! RGB LED Demo
+//!
+//! This example drives an SK68XX RGB LED, which is connected to a pin on the
+//! official DevKits.
+//!
+//! The demo will leverage the [`smart_leds`](https://crates.io/crates/smart-leds)
+//! crate functionality to circle through the HSV hue color space (with
+//! saturation and value both at 255). Additionally, we apply a gamma correction
+//! and limit the brightness to 10 (out of 255).
+//!
+//! The following wiring is assumed for ESP32:
+//! - LED => GPIO33
+//! The following wiring is assumed for ESP32C3:
+//! - LED => GPIO8
+//! The following wiring is assumed for ESP32C6, ESP32H2:
+//! - LED => GPIO8
+//! The following wiring is assumed for ESP32S2:
+//! - LED => GPIO18
+//! The following wiring is assumed for ESP32S3:
+//! - LED => GPIO48
+
+#![no_std]
+#![no_main]
+
+use esp_backtrace as _;
+use esp_hal::{delay::Delay, gpio::Io, prelude::*, rmt::Rmt};
+use esp_hal_smartled::{smartLedBuffer, SmartLedsAdapter};
+use smart_leds::{
+    brightness, gamma,
+    hsv::{hsv2rgb, Hsv},
+    SmartLedsWrite,
+};
+
+#[entry]
+fn main() -> ! {
+    let peripherals = esp_hal::init(esp_hal::Config::default());
+
+    let io = Io::new(peripherals.GPIO, peripherals.IO_MUX);
+
+    // Each devkit uses a unique GPIO for the RGB LED, so in order to support
+    // all chips we must unfortunately use `#[cfg]`s:
+    cfg_if::cfg_if! {
+        if #[cfg(feature = "esp32")] {
+            let led_pin = io.pins.gpio33;
+        } else if #[cfg(feature = "esp32c3")] {
+            let led_pin = io.pins.gpio8;
+        } else if #[cfg(any(feature = "esp32c6", feature = "esp32h2"))] {
+            let led_pin = io.pins.gpio8;
+        } else if #[cfg(feature = "esp32s2")] {
+            let led_pin = io.pins.gpio18;
+        } else if #[cfg(feature = "esp32s3")] {
+            let led_pin = io.pins.gpio48;
+        }
+    }
+
+    // Configure RMT peripheral globally
+    cfg_if::cfg_if! {
+        if #[cfg(feature = "esp32h2")] {
+            let freq = 32.MHz();
+        } else {
+            let freq = 80.MHz();
+        }
+    }
+
+    let rmt = Rmt::new(peripherals.RMT, freq).unwrap();
+
+    // We use one of the RMT channels to instantiate a `SmartLedsAdapter` which can
+    // be used directly with all `smart_led` implementations
+    let rmt_buffer = smartLedBuffer!(1);
+    let mut led = SmartLedsAdapter::new(rmt.channel0, led_pin, rmt_buffer);
+
+    let delay = Delay::new();
+
+    let mut color = Hsv {
+        hue: 0,
+        sat: 255,
+        val: 255,
+    };
+    let mut data;
+
+    loop {
+        // Iterate over the rainbow!
+        for hue in 0..=255 {
+            color.hue = hue;
+            // Convert from the HSV color space (where we can easily transition from one
+            // color to the other) to the RGB color space that we can then send to the LED
+            data = [hsv2rgb(color)];
+            // When sending to the LED, we do a gamma correction first (see smart_leds
+            // documentation for details) and then limit the brightness to 10 out of 255 so
+            // that the output it's not too bright.
+            led.write(brightness(gamma(data.iter().cloned()), 10))
+                .unwrap();
+            delay.delay_millis(20);
+        }
+    }
+}