Add explicit support for arduino-nano

1. Add the arduino-nano feature flag to arduino-hal.
2. Make the ADC6 and ADC7 pins only available for nano, not for uno.
3. Add an example crate for arduino-nano with just a blink and ADC example.

Cargo.toml

@@ -24,8 +24,9 @@ members = [
 
     # Examples
     "examples/arduino-leonardo",
-    "examples/arduino-uno",
     "examples/arduino-mega2560",
+    "examples/arduino-nano",
+    "examples/arduino-uno",
 ]
 exclude = [
     # The RAVEDUDE! Yeah!

arduino-hal/Cargo.toml

@@ -10,9 +10,10 @@ rt = ["atmega-hal/rt"]
 
 board-selected = []
 mcu-atmega=[]
-arduino-uno = ["mcu-atmega", "atmega-hal/atmega328p", "board-selected"]
 arduino-leonardo = ["mcu-atmega", "atmega-hal/atmega32u4", "board-selected"]
 arduino-mega2560 = ["mcu-atmega", "atmega-hal/atmega2560", "board-selected"]
+arduino-nano = ["mcu-atmega", "atmega-hal/atmega328p", "board-selected"]
+arduino-uno = ["mcu-atmega", "atmega-hal/atmega328p", "atmega-hal/disable-unused-adc", "board-selected"]
 
 [dependencies]
 cfg-if = "1"

arduino-hal/src/clock.rs

@@ -1,10 +1,11 @@
 pub use avr_hal_generic::clock::*;
 
 pub(crate) mod default {
-    #[cfg(feature = "arduino-uno")]
-    pub type DefaultClock = avr_hal_generic::clock::MHz16;
-    #[cfg(feature = "arduino-leonardo")]
-    pub type DefaultClock = avr_hal_generic::clock::MHz16;
-    #[cfg(feature = "arduino-mega2560")]
+    #[cfg(any(
+        feature = "arduino-leonardo",
+        feature = "arduino-mega2560",
+        feature = "arduino-nano",
+        feature = "arduino-uno",
+    ))]
     pub type DefaultClock = avr_hal_generic::clock::MHz16;
 }

arduino-hal/src/lib.rs

@@ -6,9 +6,10 @@ compile_error!(
 
     Please select one of the following
 
-    * arduino-uno
     * arduino-leonardo
     * arduino-mega2560
+    * arduino-nano
+    * arduino-uno
     "
 );
 
@@ -74,7 +75,7 @@ pub use usart::Usart;
 #[cfg(feature = "board-selected")]
 pub mod prelude {
     cfg_if::cfg_if! {
-        if #[cfg(feature = "arduino-uno")] {
+        if #[cfg(any(feature = "arduino-mega2560", feature = "arduino-uno"))] {
             pub use crate::hal::usart::BaudrateArduinoExt as _;
         } else {
             pub use crate::hal::usart::BaudrateExt as _;
@@ -94,31 +95,33 @@ macro_rules! pins {
     };
 }
 
-#[cfg(any(feature = "arduino-uno"))]
+#[cfg(any(feature = "arduino-leonardo"))]
 #[macro_export]
 macro_rules! default_serial {
     ($p:expr, $pins:expr, $baud:expr) => {
         $crate::Usart::new(
-            $p.USART0,
+            $p.USART1,
             $pins.d0,
             $pins.d1.into_output(),
-            $crate::hal::usart::BaudrateArduinoExt::into_baudrate($baud),
+            $crate::hal::usart::BaudrateExt::into_baudrate($baud),
         )
     };
 }
-#[cfg(any(feature = "arduino-leonardo"))]
+// See comment in avr-hal-generic/src/usart.rs for why these boards use
+// the BaudrateArduinoExt trait instead of BaudrateExt
+#[cfg(any(feature = "arduino-mega2560", feature = "arduino-uno"))]
 #[macro_export]
 macro_rules! default_serial {
     ($p:expr, $pins:expr, $baud:expr) => {
         $crate::Usart::new(
-            $p.USART1,
+            $p.USART0,
             $pins.d0,
             $pins.d1.into_output(),
-            $crate::hal::usart::BaudrateExt::into_baudrate($baud),
+            $crate::hal::usart::BaudrateArduinoExt::into_baudrate($baud),
         )
     };
 }
-#[cfg(any(feature = "arduino-mega2560"))]
+#[cfg(feature = "arduino-nano")]
 #[macro_export]
 macro_rules! default_serial {
     ($p:expr, $pins:expr, $baud:expr) => {

arduino-hal/src/port/mod.rs

@@ -2,11 +2,11 @@
 mod leonardo;
 #[cfg(feature = "arduino-leonardo")]
 pub use leonardo::*;
-#[cfg(feature = "arduino-uno")]
-mod uno;
-#[cfg(feature = "arduino-uno")]
-pub use uno::*;
 #[cfg(feature = "arduino-mega2560")]
 mod mega2560;
 #[cfg(feature = "arduino-mega2560")]
 pub use mega2560::*;
+#[cfg(any(feature = "arduino-nano", feature = "arduino-uno"))]
+mod uno;
+#[cfg(any(feature = "arduino-nano", feature = "arduino-uno"))]
+pub use uno::*;

examples/arduino-nano/.cargo/config.toml

@@ -0,0 +1,8 @@
+[build]
+target = "../../avr-specs/avr-atmega328p.json"
+
+[target.'cfg(target_arch = "avr")']
+runner = "ravedude uno -cb 57600"
+
+[unstable]
+build-std = ["core"]

examples/arduino-nano/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "arduino-nano-examples"
+version = "0.0.0"
+authors = ["David R. Morrison <[email protected]>"]
+edition = "2018"
+publish = false
+
+[dependencies]
+panic-halt = "0.2.0"
+ufmt = "0.1.0"
+nb = "0.1.2"
+embedded-hal = "0.2.3"
+
+[dependencies.arduino-hal]
+path = "../../arduino-hal/"
+features = ["arduino-nano"]

examples/arduino-nano/src/bin/nano-adc.rs

@@ -0,0 +1,58 @@
+#![no_std]
+#![no_main]
+
+use arduino_hal::prelude::*;
+use panic_halt as _;
+
+use arduino_hal::adc;
+
+#[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);
+
+    let mut adc = arduino_hal::Adc::new(dp.ADC, Default::default());
+
+    let (vbg, gnd, tmp) = (
+        adc.read_blocking(&adc::channel::Vbg),
+        adc.read_blocking(&adc::channel::Gnd),
+        adc.read_blocking(&adc::channel::Temperature),
+    );
+    ufmt::uwriteln!(&mut serial, "Vbandgap: {}", vbg).void_unwrap();
+    ufmt::uwriteln!(&mut serial, "Ground: {}", gnd).void_unwrap();
+    ufmt::uwriteln!(&mut serial, "Temperature: {}", tmp).void_unwrap();
+
+    let a0 = pins.a0.into_analog_input(&mut adc);
+    let a1 = pins.a1.into_analog_input(&mut adc);
+    let a2 = pins.a2.into_analog_input(&mut adc);
+    let a3 = pins.a3.into_analog_input(&mut adc);
+    let a4 = pins.a4.into_analog_input(&mut adc);
+    let a5 = pins.a5.into_analog_input(&mut adc);
+
+    loop {
+        let values = [
+            a0.analog_read(&mut adc),
+            a1.analog_read(&mut adc),
+            a2.analog_read(&mut adc),
+            a3.analog_read(&mut adc),
+            a4.analog_read(&mut adc),
+            a5.analog_read(&mut adc),
+        ];
+
+        for (i, v) in values.iter().enumerate() {
+            ufmt::uwrite!(&mut serial, "A{}: {} ", i, v).void_unwrap();
+        }
+
+        // Arduino Nano has two more ADC pins A6 and A7.  Accessing them works a bit different from
+        // the other pins as they are not normal IO pins.  The code below shows how it works.
+        let (a6, a7) = (
+            adc.read_blocking(&adc::channel::ADC6),
+            adc.read_blocking(&adc::channel::ADC7),
+        );
+        ufmt::uwrite!(&mut serial, "A6: {} A7: {}", a6, a7).void_unwrap();
+
+        ufmt::uwriteln!(&mut serial, "").void_unwrap();
+        arduino_hal::delay_ms(1000);
+    }
+}

examples/arduino-nano/src/bin/nano-blink.rs

@@ -0,0 +1,25 @@
+#![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);
+
+    // Digital pin 13 is also connected to an onboard LED marked "L"
+    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);
+    }
+}

examples/arduino-uno/src/bin/uno-adc.rs

@@ -44,14 +44,6 @@ fn main() -> ! {
             ufmt::uwrite!(&mut serial, "A{}: {} ", i, v).void_unwrap();
         }
 
-        // Arduino Nano has two more ADC pins A6 and A7.  Accessing them works a bit different from
-        // the other pins as they are not normal IO pins.  The code below shows how it works.
-        let (a6, a7) = (
-            adc.read_blocking(&adc::channel::ADC6),
-            adc.read_blocking(&adc::channel::ADC7),
-        );
-        ufmt::uwrite!(&mut serial, "A6: {} A7: {}", a6, a7).void_unwrap();
-
         ufmt::uwriteln!(&mut serial, "").void_unwrap();
         arduino_hal::delay_ms(1000);
     }

mcu/atmega-hal/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2018"
 [features]
 rt = ["avr-device/rt"]
 device-selected = []
+disable-unused-adc = []
 atmega48p = ["avr-device/atmega48p", "device-selected"]
 atmega168 = ["avr-device/atmega168", "device-selected"]
 atmega328p = ["avr-device/atmega328p", "device-selected"]

mcu/atmega-hal/src/adc.rs

@@ -22,18 +22,24 @@ pub type Channel = avr_hal_generic::adc::Channel<crate::Atmega, crate::pac::ADC>
 /// let value = adc.read_blocking(&channel::Vbg);
 /// ```
 pub mod channel {
-    #[cfg(any(
-        feature = "atmega168",
-        feature = "atmega328p",
-        feature = "atmega328pb",
-        feature = "atmega48p"
+    #[cfg(all(
+        any(
+            feature = "atmega168",
+            feature = "atmega328p",
+            feature = "atmega328pb",
+            feature = "atmega48p",
+        ),
+        not(feature = "disable-unused-adc"),
     ))]
     pub struct ADC6;
-    #[cfg(any(
-        feature = "atmega168",
-        feature = "atmega328p",
-        feature = "atmega328pb",
-        feature = "atmega48p"
+    #[cfg(all(
+        any(
+            feature = "atmega168",
+            feature = "atmega328p",
+            feature = "atmega328pb",
+            feature = "atmega48p"
+        ),
+        not(feature = "disable-unused-adc"),
     ))]
     pub struct ADC7;
     #[cfg(any(
@@ -87,7 +93,9 @@ avr_hal_generic::impl_adc! {
         port::PC5: (crate::pac::adc::admux::MUX_A::ADC5, didr0::adc5d),
     },
     channels: {
+        #[cfg(not(feature = "disable-unused-adc"))]
         channel::ADC6: crate::pac::adc::admux::MUX_A::ADC6,
+        #[cfg(not(feature = "disable-unused-adc"))]
         channel::ADC7: crate::pac::adc::admux::MUX_A::ADC7,
         channel::Vbg: crate::pac::adc::admux::MUX_A::ADC_VBG,
         channel::Gnd: crate::pac::adc::admux::MUX_A::ADC_GND,