refactor: LoRaBoard trait with full associated types + BoardParts

- LoRaBoard trait now has associated types: RadioParts, CommParts, DisplayParts, DisplayDriver
- into_parts() is on the trait (enforced by compiler, not implicit convention)
- BoardParts<R, C, D> struct replaces tuple return from into_parts()
- mac_address() stays on trait, MAC also in BoardParts for convenience
- Removed mac field from DisplayParts (display task calls Board::mac_address())
- DisplayDriver associated type requires DrawTarget<Color = BinaryColor>

src/board/rak_wisblock_4631.rs

@@ -9,7 +9,7 @@ use embassy_time::Delay;
 use lora_phy::iv::GenericSx126xInterfaceVariant;
 use lora_phy::sx126x::{self, Sx1262, Sx126x};
 
-use super::traits::LoRaBoard;
+use super::traits::{BoardParts, LoRaBoard};
 use crate::hal::nrf52840 as mcu;
 
 // ── Concrete peripheral types ───────────────────────────────────────
@@ -27,6 +27,23 @@ pub type DisplayDriver = ssd1306::Ssd1306Async<
     ssd1306::mode::BufferedGraphicsModeAsync<ssd1306::size::DisplaySize128x64>,
 >;
 
+// ── Peripheral bundles ──────────────────────────────────────────────
+
+pub struct RadioParts {
+    pub driver: RadioDriver,
+    pub delay: Delay,
+}
+
+pub struct UsbParts {
+    pub driver: UsbDriver,
+}
+
+pub struct DisplayParts {
+    pub i2c: DisplayI2c,
+}
+
+// ── Display init ────────────────────────────────────────────────────
+
 pub async fn create_display(i2c: DisplayI2c) -> Option<DisplayDriver> {
     use ssd1306::mode::DisplayConfigAsync;
     use ssd1306::prelude::{Brightness, DisplayRotation};
@@ -46,22 +63,6 @@ pub async fn create_display(i2c: DisplayI2c) -> Option<DisplayDriver> {
     Some(display)
 }
 
-// ── Peripheral bundles ──────────────────────────────────────────────
-
-pub struct RadioParts {
-    pub driver: RadioDriver,
-    pub delay: Delay,
-}
-
-pub struct UsbParts {
-    pub driver: UsbDriver,
-}
-
-pub struct DisplayParts {
-    pub i2c: DisplayI2c,
-    pub mac: [u8; 6],
-}
-
 // ── Board init ──────────────────────────────────────────────────────
 
 pub struct Board {
@@ -72,6 +73,11 @@ impl LoRaBoard for Board {
     const NAME: &'static str = "RAK WisBlock 4631";
     const TX_POWER_RANGE: (i8, i8) = (-9, 22);
 
+    type RadioParts = RadioParts;
+    type CommParts = UsbParts;
+    type DisplayParts = DisplayParts;
+    type DisplayDriver = DisplayDriver;
+
     fn init() -> Self {
         let p = embassy_nrf::init(Default::default());
         Self { p }
@@ -80,10 +86,8 @@ impl LoRaBoard for Board {
     fn mac_address() -> [u8; 6] {
         mcu::mac_address()
     }
-}
 
-impl Board {
-    pub fn into_parts(self) -> (RadioParts, UsbParts, Option<DisplayParts>) {
+    fn into_parts(self) -> BoardParts<RadioParts, UsbParts, DisplayParts> {
         let p = self.p;
 
         // ── SPI bus for SX1262 ──────────────────────────────────
@@ -95,7 +99,6 @@ impl Board {
         let nss = Output::new(p.P1_10, Level::High, OutputDrive::Standard);
         let spi_device = SpiDevice::new(spi_bus, nss);
 
-        // ── SX1262 control pins ─────────────────────────────────
         let reset = Output::new(p.P1_06, Level::High, OutputDrive::Standard);
         let dio1 = Input::new(p.P1_15, Pull::Down);
         let busy = Input::new(p.P1_14, Pull::Down);
@@ -117,7 +120,7 @@ impl Board {
 
         // ── USB ─────────────────────────────────────────────────
         let vbus = mcu::alloc_vbus_detect(true, false);
-        let usb = UsbParts {
+        let host = UsbParts {
             driver: Driver::new(p.USBD, mcu::Irqs, vbus),
         };
 
@@ -126,9 +129,13 @@ impl Board {
         let i2c = embassy_nrf::twim::Twim::new(
             p.TWISPI0, mcu::Irqs, p.P0_13, p.P0_14, twim::Config::default(), twim_buf,
         );
-        let mac = Self::mac_address();
-        let display = Some(DisplayParts { i2c, mac });
+        let display = Some(DisplayParts { i2c });
 
-        (radio, usb, display)
+        BoardParts {
+            radio,
+            host,
+            display,
+            mac: Self::mac_address(),
+        }
     }
 }