arduino-hal: Add support for Arduino Micro

Ivan-Johnson · Rahix · commit ff4909c00cee · 2025-12-21T00:15:07.000+01:00
Fixes #161
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -50,6 +50,9 @@ jobs:
           - type: board
             name: arduino-nano
             examples: true
+          - type: board
+            name: arduino-micro
+            examples: true
           - type: board
             name: nano168
             examples: true
diff --git a/Cargo.toml b/Cargo.toml
@@ -28,6 +28,7 @@ members = [
     "examples/arduino-mega2560",
     "examples/arduino-mega1280",
     "examples/arduino-nano",
+    "examples/arduino-micro",
     "examples/arduino-uno",
     "examples/atmega2560",
     "examples/nano168",
diff --git a/arduino-hal/Cargo.toml b/arduino-hal/Cargo.toml
@@ -22,6 +22,7 @@ arduino-leonardo = ["mcu-atmega", "atmega-hal/atmega32u4", "board-selected"]
 arduino-mega2560 = ["mcu-atmega", "atmega-hal/atmega2560", "board-selected"]
 arduino-mega1280 = ["mcu-atmega", "atmega-hal/atmega1280", "board-selected"]
 arduino-nano = ["mcu-atmega", "atmega-hal/atmega328p", "atmega-hal/enable-extra-adc", "board-selected"]
+arduino-micro = ["mcu-atmega", "atmega-hal/atmega32u4", "board-selected"]
 arduino-uno = ["mcu-atmega", "atmega-hal/atmega328p", "board-selected"]
 trinket-pro = ["mcu-atmega", "atmega-hal/atmega328p", "board-selected"]
 sparkfun-promicro = ["mcu-atmega", "atmega-hal/atmega32u4", "board-selected"]
diff --git a/arduino-hal/src/clock.rs b/arduino-hal/src/clock.rs
@@ -20,6 +20,7 @@ pub(crate) mod default {
         feature = "arduino-mega2560",
         feature = "arduino-mega1280",
         feature = "arduino-nano",
+        feature = "arduino-micro",
         feature = "arduino-uno",
         feature = "sparkfun-promicro",
         feature = "sparkfun-promini-5v",
diff --git a/arduino-hal/src/lib.rs b/arduino-hal/src/lib.rs
@@ -10,6 +10,7 @@
 #![cfg_attr(feature = "arduino-leonardo", doc = "**Arduino Leonardo**.")]
 #![cfg_attr(feature = "arduino-mega2560", doc = "**Arduino Mega 2560**.")]
 #![cfg_attr(feature = "arduino-mega1280", doc = "**Arduino Mega 1280**.")]
+#![cfg_attr(feature = "arduino-micro", doc = "**Arduino Micro**.")]
 #![cfg_attr(feature = "arduino-nano", doc = "**Arduino Nano**.")]
 #![cfg_attr(feature = "arduino-uno", doc = "**Arduino Uno**.")]
 #![cfg_attr(feature = "sparkfun-promicro", doc = "**SparkFun ProMicro**.")]
@@ -64,6 +65,7 @@ compile_error!(
     * arduino-leonardo
     * arduino-mega2560
     * arduino-mega1280
+    * arduino-micro
     * arduino-nano
     * arduino-uno
     * sparkfun-promicro
@@ -238,7 +240,7 @@ macro_rules! pins {
 /// let pins = arduino_hal::pins!(dp);
 /// let serial = arduino_hal::default_serial!(dp, pins, 57600);
 /// ```
-#[cfg(any(feature = "arduino-leonardo"))]
+#[cfg(any(feature = "arduino-leonardo", feature = "arduino-micro"))]
 #[macro_export]
 macro_rules! default_serial {
     ($p:expr, $pins:expr, $baud:expr) => {
diff --git a/arduino-hal/src/port/leonardo.rs b/arduino-hal/src/port/leonardo.rs
@@ -1,7 +1,7 @@
 pub use atmega_hal::port::{mode, Pin, PinMode, PinOps};
 
 avr_hal_generic::renamed_pins! {
-    /// Pins of the **Arduino Leonardo**.
+    /// Pins of the **Arduino Leonardo** and **Arduno Micro**.
     ///
     /// This struct is best initialized via the [`arduino_hal::pins!()`][crate::pins] macro.
     pub struct Pins {
diff --git a/arduino-hal/src/port/mod.rs b/arduino-hal/src/port/mod.rs
@@ -19,9 +19,9 @@
 mod diecimila;
 #[cfg(feature = "arduino-diecimila")]
 pub use diecimila::*;
-#[cfg(feature = "arduino-leonardo")]
+#[cfg(any(feature = "arduino-leonardo", feature = "arduino-micro"))]
 mod leonardo;
-#[cfg(feature = "arduino-leonardo")]
+#[cfg(any(feature = "arduino-leonardo", feature = "arduino-micro"))]
 pub use leonardo::*;
 #[cfg(any(feature = "arduino-mega2560", feature = "arduino-mega1280"))]
 mod mega;
diff --git a/examples/arduino-leonardo/src/bin/leonardo-usart.rs b/examples/arduino-leonardo/src/bin/leonardo-usart.rs
@@ -1,3 +1,9 @@
+/*!
+ * Demonstration of writing to and reading from the serial console.
+ *
+ * Note: To communicate with the Arduino over its hardware serial port, you must
+ * connect an external USB-to-UART adapter to the board’s RX and TX pins.
+ */
 #![no_std]
 #![no_main]
 
diff --git a/examples/arduino-micro/.cargo/config.toml b/examples/arduino-micro/.cargo/config.toml
@@ -0,0 +1,9 @@
+[build]
+target = "avr-none"
+rustflags = ["-C", "target-cpu=atmega32u4"]
+
+[target.'cfg(target_arch = "avr")']
+runner = "ravedude"
+
+[unstable]
+build-std = ["core"]
diff --git a/examples/arduino-micro/Cargo.toml b/examples/arduino-micro/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "arduino-micro-examples"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+panic-halt = "1.0.0"
+ufmt = "0.2.0"
+nb = "1.1.0"
+
+[dependencies.arduino-hal]
+path = "../../arduino-hal/"
+features = ["arduino-micro"]
diff --git a/examples/arduino-micro/Ravedude.toml b/examples/arduino-micro/Ravedude.toml
@@ -0,0 +1,12 @@
+[general]
+board = "micro"
+
+# The Arduino Micro does not have a UART console like other Arduino boards.
+# Instead, it can emulate a console device over USB, but this is not yet
+# supported in `avr-hal`.  To get console output from an Arduino Micro, you
+# need to connect an external usb-serial converter to the TX/RX pins of your
+# board.
+open-console = false
+
+# For documentation about this file, check here:
+# https://github.com/Rahix/avr-hal/blob/main/ravedude/README.md#ravedudetoml-format
diff --git a/examples/arduino-micro/src/bin/micro-blink.rs b/examples/arduino-micro/src/bin/micro-blink.rs
@@ -0,0 +1,28 @@
+/*!
+ * Blink the builtin LED - the "Hello World" of embedded programming.
+ */
+#![no_std]
+#![no_main]
+
+use panic_halt as _;
+
+#[arduino_hal::entry]
+fn main() -> ! {
+    let dp = arduino_hal::Peripherals::take().unwrap();
+    let pins = arduino_hal::pins!(dp);
+
+    // pin D13 is connected to an onboard LED
+    let mut led = pins.d13.into_output();
+    led.set_high();
+
+    loop {
+        led.toggle();
+        arduino_hal::delay_ms(100);
+        led.toggle();
+        arduino_hal::delay_ms(100);
+        led.toggle();
+        arduino_hal::delay_ms(100);
+        led.toggle();
+        arduino_hal::delay_ms(800);
+    }
+}
diff --git a/examples/arduino-micro/src/bin/micro-simple-pwm.rs b/examples/arduino-micro/src/bin/micro-simple-pwm.rs
@@ -0,0 +1,33 @@
+/*!
+ * Example of using simple_pwm to fade in and out the builtin LED.
+ *
+ * The Arduino Micro's bootloader does a similar animation, with a period of
+ * about one second per pulse. This example animation has a period of about five
+ * seconds per pulse in order to make it easily distinguishable from the
+ * bootloader's animation.
+ */
+#![no_std]
+#![no_main]
+
+use arduino_hal::simple_pwm::IntoPwmPin;
+use arduino_hal::simple_pwm::Prescaler;
+use arduino_hal::simple_pwm::Timer4Pwm;
+use panic_halt as _;
+
+#[arduino_hal::entry]
+fn main() -> ! {
+    let dp = arduino_hal::Peripherals::take().unwrap();
+    let pins = arduino_hal::pins!(dp);
+
+    let timer4 = Timer4Pwm::new(dp.TC4, Prescaler::Prescale64);
+
+    let mut pwm_led = pins.d13.into_output().into_pwm(&timer4);
+    pwm_led.enable();
+
+    loop {
+        for x in (0..=255).chain((0..=254).rev()) {
+            pwm_led.set_duty(x);
+            arduino_hal::delay_ms(10);
+        }
+    }
+}
diff --git a/examples/arduino-micro/src/bin/micro-usart.rs b/examples/arduino-micro/src/bin/micro-usart.rs
@@ -0,0 +1,28 @@
+/*!
+ * Demonstration of writing to and reading from the serial console.
+ *
+ * Note: To communicate with the Arduino over its hardware serial port, you must
+ * connect an external USB-to-UART adapter to the board’s RX and TX pins.
+ */
+#![no_std]
+#![no_main]
+
+use arduino_hal::prelude::*;
+use panic_halt as _;
+
+#[arduino_hal::entry]
+fn main() -> ! {
+    let dp = arduino_hal::Peripherals::take().unwrap();
+    let pins = arduino_hal::pins!(dp);
+    let mut serial = arduino_hal::default_serial!(dp, pins, 57600);
+
+    ufmt::uwriteln!(&mut serial, "Hello from Arduino!\r").unwrap_infallible();
+
+    loop {
+        // Read a byte from the serial connection
+        let b = nb::block!(serial.read()).unwrap_infallible();
+
+        // Answer
+        ufmt::uwriteln!(&mut serial, "Got {}!\r", b).unwrap_infallible();
+    }
+}
