feat: add ELECROW ThinkNode-M2 board support

ESP32-S3 + SX1262 + 1.3" SH1106 OLED + CP2102 UART bridge +
1000 mAh Li-Po. Pin map verified against Meshtastic's
variants/esp32s3/ELECROW-ThinkNode-M2. DIO3 TCXO at 3.3 V (vs 1.8 V
on Heltec), VEXT_ENABLE active HIGH (opposite polarity), dedicated
LORA_POWER_EN on GPIO48 sequenced before SPI init. Reuses the
existing async SH1106 driver at I2C address 0x3C.

Refactors hal::esp32s3::{init_spi,init_i2c} and board::esp32s3::init_radio
to accept generic GPIO bounds so ESP32-S3 boards with different pin
assignments can share the helpers. init_radio now takes a
TcxoCtrlVoltage parameter instead of hardcoding Ctrl1V8.

Incidental cleanups needed to make `just check-all` green:

- Replace the core::mem::forget(output) pattern with let _foo = ...;
  current esp-hal makes Output non-Drop, so forget is a no-op that
  trips clippy's forget_non_drop lint.

- Switch justfile xtensa builds from `cargo +nightly` with a RUSTC
  override to `cargo +esp` so the compiler and rust-src versions stay
  aligned. Public nightly's rust-src had drifted two months ahead of
  the esp fork and broke -Zbuild-std on core.

CHANGELOG.md

@@ -7,8 +7,30 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+### Added
+
+- ELECROW ThinkNode-M2 board support (ESP32-S3 + SX1262 + 1.3" SH1106 OLED
+  via CP2102 UART bridge, 1000 mAh Li-Po handheld)
+  - Pin map verified against Meshtastic's
+    `variants/esp32s3/ELECROW-ThinkNode-M2`
+  - DIO3 TCXO driven at 3.3 V (not 1.8 V like Heltec)
+  - Dedicated `LORA_POWER_EN` (GPIO48) sequenced HIGH before SPI init
+  - `VEXT_ENABLE` (GPIO46) is active HIGH — opposite polarity from Heltec
+  - Reuses the existing async SH1106 driver at I2C address 0x3C
+
 ### Changed
 
+- `hal::esp32s3::{init_spi, init_i2c}` and `board::esp32s3::init_radio` are
+  now generic over GPIO type, so ESP32-S3 boards with different pin
+  assignments can share the helpers.
+- `board::esp32s3::init_radio` takes a `TcxoCtrlVoltage` parameter instead
+  of hardcoding `Ctrl1V8` — needed for ThinkNode-M2's 3.3 V TCXO.
+- SSD1306 display items in `board::esp32s3` are now cfg-gated to Heltec
+  boards (ThinkNode-M2 supplies its own SH1106 `create_display`).
+- `justfile` uses `cargo +esp` for Xtensa targets instead of `cargo +nightly`
+  with a `RUSTC=esp` override — the self-contained esp toolchain keeps its
+  cargo, rustc, and rust-src versions aligned. Public nightly's rust-src
+  had drifted ahead of the esp fork, breaking `-Zbuild-std`.
 - Migrated to embassy-executor 0.10 and embassy-rp 0.10
 - ESP crates (esp-hal, esp-rtos, esp-backtrace, esp-println) patched from
   esp-rs/esp-hal main branch until esp-rtos publishes with 0.10 support
@@ -22,6 +44,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Fixed
 
+- `core::mem::forget(output)` pattern in ESP32-S3 board files is now
+  `let _vext = Output::new(...)` — current esp-hal makes `Output` non-Drop,
+  which made `forget` a no-op and tripped clippy's `forget_non_drop` lint.
 - UART boards (heltec_v3_uart) display stuck on splash screen after boot.
   Host task sent `DisplayCommand::Reset` (which sets disconnected=true) instead
   of `DisplayCommand::On`. UART has no DTR, so nothing ever cleared it.

Cargo.toml

@@ -105,6 +105,12 @@ heltec_v4 = [
   "dep:esp-println",
   "dep:esp-rtos",
 ]
+elecrow_thinknode_m2 = [
+  "dep:esp-backtrace",
+  "dep:esp-hal",
+  "dep:esp-println",
+  "dep:esp-rtos",
+]
 rak_wisblock_4631 = [
   "dep:cortex-m",
   "dep:cortex-m-rt",

README.md

@@ -23,6 +23,7 @@ All commands are run from the `firmware/` directory.
 | Heltec V3 | `heltec_v3` | ESP32-S3 | SX1262 | Native CDC-ACM | xtensa-esp32s3-none-elf |
 | Heltec V3 (UART) | `heltec_v3_uart` | ESP32-S3 | SX1262 | CP2102 bridge | xtensa-esp32s3-none-elf |
 | Heltec V4 | `heltec_v4` | ESP32-S3 | SX1262 | Native CDC-ACM | xtensa-esp32s3-none-elf |
+| ELECROW ThinkNode-M2 | `elecrow_thinknode_m2` | ESP32-S3 | SX1262 | CP2102 bridge | xtensa-esp32s3-none-elf |
 | RAK WisBlock 4631 | `rak_wisblock_4631` | nRF52840 | SX1262 | Native CDC-ACM | thumbv7em-none-eabihf |
 | Waveshare RP2040-LoRa | `waveshare_rp2040_lora` | RP2040 | SX1262 | Native CDC-ACM | thumbv6m-none-eabi |
 | Wio Tracker L1 | `wio_tracker_l1` | nRF52840 | SX1262 | Native CDC-ACM | thumbv7em-none-eabihf |

justfile

@@ -1,11 +1,15 @@
 set shell := ["bash", "-c"]
 
 # Board definitions: feature target chip
-# Xtensa targets use nightly cargo + esp rustc + -Zbuild-std=core.
+# Xtensa targets use the self-contained esp toolchain (espup-installed) with
+# `-Zbuild-std=core,alloc`. Using `+esp` rather than `+nightly` keeps the
+# compiler and rust-src versions aligned — the public nightly drifts ahead of
+# the esp fork and breaks core-stdlib compilation otherwise.
 # Tool versions are pinned in mise.toml; run `just setup` to install everything.
 heltec_v3      := "heltec_v3 xtensa-esp32s3-none-elf esp32s3"
 heltec_v3_uart := "heltec_v3_uart xtensa-esp32s3-none-elf esp32s3"
 heltec_v4      := "heltec_v4 xtensa-esp32s3-none-elf esp32s3"
+elecrow_thinknode_m2 := "elecrow_thinknode_m2 xtensa-esp32s3-none-elf esp32s3"
 rak_wisblock_4631  := "rak_wisblock_4631 thumbv7em-none-eabihf nRF52840_xxAA"
 wio_tracker_l1     := "wio_tracker_l1 thumbv7em-none-eabihf nRF52840_xxAA"
 waveshare_rp2040_lora := "waveshare_rp2040_lora thumbv6m-none-eabi rp2040"
@@ -14,7 +18,7 @@ builds_dir := "builds"
 version := `sed -n 's/^version = "\(.*\)"/\1/p' Cargo.toml`
 
 # All known boards
-boards := "heltec_v3 heltec_v3_uart heltec_v4 rak_wisblock_4631 waveshare_rp2040_lora wio_tracker_l1"
+boards := "heltec_v3 heltec_v3_uart heltec_v4 elecrow_thinknode_m2 rak_wisblock_4631 waveshare_rp2040_lora wio_tracker_l1"
 
 # Install all required tools and toolchains
 setup:
@@ -111,18 +115,18 @@ _ensure_tools:
     @mise trust --yes . 2>/dev/null; mise install --quiet
 
 # Run a cargo command for a board.
-# Xtensa: nightly cargo + esp rustc (via RUSTC override) + -Zbuild-std=core
+# Xtensa: esp toolchain (cargo + rustc + rust-src together) + -Zbuild-std=core
 [private]
 _cargo board cmd extra_args="":
     @just _ensure_tools
     @read -r feat target chip <<< "$(just _info {{board}})"; \
-    env=""; extra=""; \
+    extra=""; buildstd=""; \
     case "$target" in xtensa-*) \
         just _require_esp_toolchain; \
         [ -f "$HOME/export-esp.sh" ] && . "$HOME/export-esp.sh"; \
-        env="RUSTC=$(rustup which rustc --toolchain esp)"; extra="+nightly"; buildstd="-Zbuild-std=core,alloc";; \
+        extra="+esp"; buildstd="-Zbuild-std=core,alloc";; \
     esac; \
-    eval $env cargo $extra {{cmd}} --target "$target" --features "$feat" $buildstd {{extra_args}}
+    cargo $extra {{cmd}} --target "$target" --features "$feat" $buildstd {{extra_args}}
 
 # Ensure a board's toolchain is available, auto-installing if needed
 [private]
@@ -133,17 +137,15 @@ _can_build board:
         *) rustup target list --installed | grep -q "^$target$" || rustup target add "$target" ;; \
     esac
 
-# Ensure the ESP Xtensa toolchain is installed (espup installed via mise)
+# Ensure the ESP Xtensa toolchain is installed (espup installed via mise).
+# The esp toolchain ships with its own cargo, rustc, and rust-src — no extra
+# components are needed on top.
 [private]
 _require_esp_toolchain:
     @just _ensure_tools
     @if ! rustup toolchain list | grep -q "^esp"; then \
         echo "ESP toolchain not found, installing via espup (this may take a while)..." >&2; \
         espup install || { echo "error: espup install failed" >&2; exit 1; }; \
-    fi; \
-    if ! rustup component list --toolchain nightly --installed 2>/dev/null | grep -q "^rust-src"; then \
-        echo "Installing nightly rust-src (needed for -Zbuild-std)..." >&2; \
-        rustup component add rust-src --toolchain nightly || { echo "error: failed to install rust-src" >&2; exit 1; }; \
     fi
 
 # Find a serial port matching any of the given VID:PID pairs (checked in order)
@@ -211,6 +213,7 @@ _info name:
     @if [ "{{name}}" == "heltec_v3" ]; then echo "{{heltec_v3}}"; \
      elif [ "{{name}}" == "heltec_v3_uart" ]; then echo "{{heltec_v3_uart}}"; \
      elif [ "{{name}}" == "heltec_v4" ]; then echo "{{heltec_v4}}"; \
+     elif [ "{{name}}" == "elecrow_thinknode_m2" ]; then echo "{{elecrow_thinknode_m2}}"; \
      elif [ "{{name}}" == "rak_wisblock_4631" ]; then echo "{{rak_wisblock_4631}}"; \
      elif [ "{{name}}" == "waveshare_rp2040_lora" ]; then echo "{{waveshare_rp2040_lora}}"; \
      elif [ "{{name}}" == "wio_tracker_l1" ]; then echo "{{wio_tracker_l1}}"; \

src/board/elecrow_thinknode_m2.rs

@@ -0,0 +1,141 @@
+//! ELECROW ThinkNode-M2 — ESP32-S3 Meshtastic handset with SH1106 OLED.
+//!
+//! Tamagotchi-form-factor handheld: ESP32-S3-WROOM-1-N4 + SX1262 + 1.3" SH1106
+//! OLED + CP2102 UART bridge + 1000 mAh Li-Po. Sold pre-loaded with Meshtastic;
+//! this firmware turns it into a DongLoRa radio bridge.
+//!
+//! Pin map (verified from Meshtastic's variants/esp32s3/ELECROW-ThinkNode-M2
+//! and PR meshtastic/firmware#6354):
+//!   LoRa SPI: SCK=12, MOSI=11, MISO=13, CS=10
+//!   LoRa ctl: RESET=21, BUSY=14, DIO1=3
+//!   LoRa pwr: GPIO48 (must be HIGH before any SPI traffic)
+//!   OLED:     I2C0 SDA=16, SCL=15, SH1106 @ 0x3C
+//!   VEXT:     GPIO46 (active HIGH — gates OLED supply)
+//!   UART:     TX=43, RX=44 via CP2102 bridge
+//!   LED:      GPIO6 (active HIGH indicator)
+//!
+//! Notable differences from the Heltec ESP32-S3 boards:
+//!   * Display is SH1106 (not SSD1306) — uses the existing sh1106 driver.
+//!   * VEXT_ENABLE polarity is reversed (active HIGH here, active LOW on Heltec).
+//!   * Dedicated LoRa power enable on GPIO48 — must be sequenced before SPI init.
+//!   * TCXO is driven at 3.3 V via DIO3 (Heltec uses 1.8 V).
+
+use esp_hal::gpio::{Level, Output, OutputConfig};
+
+use super::esp32s3;
+use super::traits::{BoardParts, LoRaBoard};
+use crate::driver::sh1106::Sh1106;
+use crate::driver::simple_led::SimpleLed;
+use crate::hal::esp32s3 as mcu;
+
+pub use super::esp32s3::{DisplayI2c, RadioDriver, RadioParts};
+
+// ── Concrete peripheral types ───────────────────────────────────────
+
+pub type DisplayDriver = Sh1106<DisplayI2c>;
+pub type UartDriver = esp_hal::uart::Uart<'static, esp_hal::Async>;
+pub type LedDriver = SimpleLed<Output<'static>>;
+
+// ── Peripheral bundles ──────────────────────────────────────────────
+
+pub struct UartParts {
+    pub driver: UartDriver,
+}
+
+pub struct DisplayParts {
+    pub i2c: DisplayI2c,
+}
+
+// ── Display init ────────────────────────────────────────────────────
+
+pub async fn create_display(i2c: DisplayI2c) -> Option<DisplayDriver> {
+    let mut display = Sh1106::new(i2c, 0x3C);
+
+    embassy_time::Timer::after_millis(100).await;
+    if display.init().await.is_err() {
+        defmt::error!("SH1106 display init failed");
+        return None;
+    }
+    let _ = display.set_brightness(0xFF).await;
+    Some(display)
+}
+
+// ── Board init ──────────────────────────────────────────────────────
+
+pub struct Board {
+    p: esp_hal::peripherals::Peripherals,
+}
+
+impl LoRaBoard for Board {
+    const NAME: &'static str = "ELECROW ThinkNode-M2";
+    const TX_POWER_RANGE: (i8, i8) = (-9, 22);
+
+    type RadioParts = RadioParts;
+    type CommParts = UartParts;
+    type DisplayParts = DisplayParts;
+    type DisplayDriver = DisplayDriver;
+    type LedDriver = LedDriver;
+
+    fn init() -> Self {
+        let p = esp_hal::init(esp_hal::Config::default());
+        Self { p }
+    }
+
+    fn mac_address() -> [u8; 6] {
+        mcu::mac_address()
+    }
+
+    fn into_parts(self) -> BoardParts<RadioParts, UartParts, DisplayParts, LedDriver> {
+        let p = self.p;
+
+        mcu::start_timer(p.TIMG0, p.SW_INTERRUPT);
+
+        // VEXT_ENABLE: GPIO46, active HIGH — powers OLED rail (opposite of Heltec).
+        // Output has no Drop impl, so the pin stays HIGH for program lifetime.
+        let _vext = Output::new(p.GPIO46, Level::High, OutputConfig::default());
+        esp_hal::delay::Delay::new().delay_millis(10);
+
+        // LORA_POWER_EN: GPIO48, active HIGH — must be HIGH before any SPI traffic.
+        let _lora_pwr = Output::new(p.GPIO48, Level::High, OutputConfig::default());
+        esp_hal::delay::Delay::new().delay_millis(10);
+
+        // SPI2 for SX1262: SCK=12, MOSI=11, MISO=13
+        let spi_bus = mcu::init_spi(p.SPI2, p.DMA_CH0, p.GPIO12, p.GPIO11, p.GPIO13);
+
+        // SX1262: CS=10, RESET=21, DIO1=3, BUSY=14, TCXO driven at 3.3 V via DIO3.
+        let radio = esp32s3::init_radio(
+            spi_bus,
+            p.GPIO10,
+            p.GPIO21,
+            p.GPIO3,
+            p.GPIO14,
+            lora_phy::sx126x::TcxoCtrlVoltage::Ctrl3V3,
+        );
+
+        // UART0 via CP2102 bridge: TX=43, RX=44
+        use esp_hal::uart::{Config as UartConfig, Uart};
+        let host = UartParts {
+            driver: Uart::new(p.UART0, UartConfig::default())
+                .expect("UART init")
+                .with_tx(p.GPIO43)
+                .with_rx(p.GPIO44)
+                .into_async(),
+        };
+
+        // I2C0 for SH1106 OLED: SDA=16, SCL=15
+        let i2c = mcu::init_i2c(p.I2C0, p.GPIO16, p.GPIO15);
+        let display = Some(DisplayParts { i2c });
+
+        // LED on GPIO6 (active HIGH)
+        let led_pin = Output::new(p.GPIO6, Level::Low, OutputConfig::default());
+        let led = SimpleLed(led_pin);
+
+        BoardParts {
+            radio,
+            host,
+            display,
+            led,
+            mac: Self::mac_address(),
+        }
+    }
+}

src/board/esp32s3.rs

@@ -7,7 +7,7 @@
 use embassy_embedded_hal::shared_bus::asynch::spi::SpiDevice;
 use embassy_sync::blocking_mutex::raw::NoopRawMutex;
 use embassy_time::Delay;
-use esp_hal::gpio::{Input, InputConfig, Level, Output, OutputConfig, Pull};
+use esp_hal::gpio::{Input, InputConfig, InputPin, Level, Output, OutputConfig, OutputPin, Pull};
 
 use lora_phy::iv::GenericSx126xInterfaceVariant;
 use lora_phy::sx126x::{self, Sx1262, Sx126x};
@@ -32,12 +32,17 @@ pub struct RadioParts {
     pub delay: Delay,
 }
 
+// SSD1306 display support is Heltec-specific. ESP32-S3 boards that use a
+// different controller (e.g. ThinkNode-M2 uses SH1106) provide their own
+// DisplayParts / DisplayDriver / create_display directly.
+#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4"))]
 pub struct DisplayParts {
     pub i2c: DisplayI2c,
 }
 
 // ── Display driver ──────────────────────────────────────────────────
 
+#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4"))]
 pub type DisplayDriver = ssd1306::Ssd1306Async<
     ssd1306::prelude::I2CInterface<DisplayI2c>,
     ssd1306::size::DisplaySize128x64,
@@ -45,6 +50,7 @@ pub type DisplayDriver = ssd1306::Ssd1306Async<
 >;
 
 /// Construct and initialize an SSD1306 display from raw I2C.
+#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4"))]
 pub async fn create_display(i2c: DisplayI2c) -> Option<DisplayDriver> {
     use ssd1306::mode::DisplayConfigAsync;
     use ssd1306::prelude::{Brightness, DisplayRotation};
@@ -67,12 +73,17 @@ pub async fn create_display(i2c: DisplayI2c) -> Option<DisplayDriver> {
 // ── Shared peripheral init helpers ──────────────────────────────────
 
 /// Construct SX1262 radio from an initialized SPI bus.
+///
+/// Generic over GPIO type so boards with different radio pin assignments can
+/// share this helper. `tcxo_voltage` selects the DIO3-driven TCXO supply:
+/// Heltec boards use `Ctrl1V8`, the ELECROW ThinkNode-M2 uses `Ctrl3V3`, etc.
 pub fn init_radio(
     spi_bus: &'static embassy_sync::mutex::Mutex<NoopRawMutex, SpiBus>,
-    nss_pin: esp_hal::peripherals::GPIO8<'static>,
-    reset_pin: esp_hal::peripherals::GPIO12<'static>,
-    dio1_pin: esp_hal::peripherals::GPIO14<'static>,
-    busy_pin: esp_hal::peripherals::GPIO13<'static>,
+    nss_pin: impl OutputPin + 'static,
+    reset_pin: impl OutputPin + 'static,
+    dio1_pin: impl InputPin + 'static,
+    busy_pin: impl InputPin + 'static,
+    tcxo_voltage: sx126x::TcxoCtrlVoltage,
 ) -> RadioParts {
     let nss = Output::new(nss_pin, Level::High, OutputConfig::default());
     let spi_device = SpiDevice::new(spi_bus, nss);
@@ -86,7 +97,7 @@ pub fn init_radio(
 
     let sx_config = sx126x::Config {
         chip: Sx1262,
-        tcxo_ctrl: Some(sx126x::TcxoCtrlVoltage::Ctrl1V8),
+        tcxo_ctrl: Some(tcxo_voltage),
         use_dcdc: true,
         rx_boost: false,
     };

src/board/heltec_v3.rs

@@ -53,12 +53,19 @@ impl LoRaBoard for Board {
 
         mcu::start_timer(p.TIMG0, p.SW_INTERRUPT);
 
-        // Vext power: GPIO36, active LOW to enable peripherals
-        let vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
-        core::mem::forget(vext);
+        // Vext power: GPIO36, active LOW to enable peripherals.
+        // Output has no Drop impl, so the pin stays configured for program lifetime.
+        let _vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
 
         let spi_bus = mcu::init_spi(p.SPI2, p.DMA_CH0, p.GPIO9, p.GPIO10, p.GPIO11);
-        let radio = esp32s3::init_radio(spi_bus, p.GPIO8, p.GPIO12, p.GPIO14, p.GPIO13);
+        let radio = esp32s3::init_radio(
+            spi_bus,
+            p.GPIO8,
+            p.GPIO12,
+            p.GPIO14,
+            p.GPIO13,
+            lora_phy::sx126x::TcxoCtrlVoltage::Ctrl1V8,
+        );
 
         // Note: switches internal USB PHY from Serial-JTAG to OTG.
         let usb_inst = esp_hal::otg_fs::Usb::new(p.USB0, p.GPIO20, p.GPIO19);
@@ -72,12 +79,12 @@ impl LoRaBoard for Board {
             ),
         };
 
-        // SSD1306 display reset: pulse GPIO21 low->high before I2C init
+        // SSD1306 display reset: pulse GPIO21 low->high before I2C init.
+        // Output has no Drop impl; pin stays HIGH after this block.
         let mut display_rst = Output::new(p.GPIO21, Level::Low, OutputConfig::default());
         esp_hal::delay::Delay::new().delay_millis(10);
         display_rst.set_high();
         esp_hal::delay::Delay::new().delay_millis(10);
-        core::mem::forget(display_rst);
 
         let i2c = mcu::init_i2c(p.I2C0, p.GPIO17, p.GPIO18);
         let display = Some(DisplayParts { i2c });

src/board/heltec_v3_uart.rs

@@ -52,12 +52,19 @@ impl LoRaBoard for Board {
 
         mcu::start_timer(p.TIMG0, p.SW_INTERRUPT);
 
-        // Vext power: GPIO36, active LOW to enable peripherals
-        let vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
-        core::mem::forget(vext);
+        // Vext power: GPIO36, active LOW to enable peripherals.
+        // Output has no Drop impl, so the pin stays configured for program lifetime.
+        let _vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
 
         let spi_bus = mcu::init_spi(p.SPI2, p.DMA_CH0, p.GPIO9, p.GPIO10, p.GPIO11);
-        let radio = esp32s3::init_radio(spi_bus, p.GPIO8, p.GPIO12, p.GPIO14, p.GPIO13);
+        let radio = esp32s3::init_radio(
+            spi_bus,
+            p.GPIO8,
+            p.GPIO12,
+            p.GPIO14,
+            p.GPIO13,
+            lora_phy::sx126x::TcxoCtrlVoltage::Ctrl1V8,
+        );
 
         use esp_hal::uart::{Config as UartConfig, Uart};
         let host = UartParts {
@@ -68,12 +75,12 @@ impl LoRaBoard for Board {
                 .into_async(),
         };
 
-        // SSD1306 display reset: pulse GPIO21 low->high before I2C init
+        // SSD1306 display reset: pulse GPIO21 low->high before I2C init.
+        // Output has no Drop impl; pin stays HIGH after this block.
         let mut display_rst = Output::new(p.GPIO21, Level::Low, OutputConfig::default());
         esp_hal::delay::Delay::new().delay_millis(10);
         display_rst.set_high();
         esp_hal::delay::Delay::new().delay_millis(10);
-        core::mem::forget(display_rst);
 
         let i2c = mcu::init_i2c(p.I2C0, p.GPIO17, p.GPIO18);
         let display = Some(DisplayParts { i2c });

src/board/heltec_v4.rs

@@ -46,12 +46,19 @@ impl LoRaBoard for Board {
 
         mcu::start_timer(p.TIMG0, p.SW_INTERRUPT);
 
-        // Vext power: GPIO36, active LOW to enable peripherals
-        let vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
-        core::mem::forget(vext);
+        // Vext power: GPIO36, active LOW to enable peripherals.
+        // Output has no Drop impl, so the pin stays configured for program lifetime.
+        let _vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
 
         let spi_bus = mcu::init_spi(p.SPI2, p.DMA_CH0, p.GPIO9, p.GPIO10, p.GPIO11);
-        let radio = esp32s3::init_radio(spi_bus, p.GPIO8, p.GPIO12, p.GPIO14, p.GPIO13);
+        let radio = esp32s3::init_radio(
+            spi_bus,
+            p.GPIO8,
+            p.GPIO12,
+            p.GPIO14,
+            p.GPIO13,
+            lora_phy::sx126x::TcxoCtrlVoltage::Ctrl1V8,
+        );
 
         // Note: switches internal USB PHY from Serial-JTAG to OTG.
         let usb_inst = esp_hal::otg_fs::Usb::new(p.USB0, p.GPIO20, p.GPIO19);
@@ -65,12 +72,12 @@ impl LoRaBoard for Board {
             ),
         };
 
-        // SSD1315 display reset: pulse GPIO21 low->high before I2C init
+        // SSD1315 display reset: pulse GPIO21 low->high before I2C init.
+        // Output has no Drop impl; pin stays HIGH after this block.
         let mut display_rst = Output::new(p.GPIO21, Level::Low, OutputConfig::default());
         esp_hal::delay::Delay::new().delay_millis(10);
         display_rst.set_high();
         esp_hal::delay::Delay::new().delay_millis(10);
-        core::mem::forget(display_rst);
 
         let i2c = mcu::init_i2c(p.I2C0, p.GPIO17, p.GPIO18);
         let display = Some(DisplayParts { i2c });

src/driver/mod.rs

@@ -1,5 +1,5 @@
-#[cfg(feature = "wio_tracker_l1")]
+#[cfg(any(feature = "wio_tracker_l1", feature = "elecrow_thinknode_m2"))]
 pub mod sh1106;
 
-#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "wio_tracker_l1", feature = "waveshare_rp2040_lora"))]
+#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "elecrow_thinknode_m2", feature = "wio_tracker_l1", feature = "waveshare_rp2040_lora"))]
 pub mod simple_led;

src/hal/esp32s3.rs

@@ -6,6 +6,7 @@
 
 use embassy_sync::blocking_mutex::raw::NoopRawMutex;
 use esp_hal::dma::{DmaRxBuf, DmaTxBuf};
+use esp_hal::gpio::interconnect::{PeripheralInput, PeripheralOutput};
 use esp_hal::i2c::master::{Config as I2cConfig, I2c};
 use esp_hal::spi::master::{Config as SpiConfig, Spi, SpiDmaBus};
 use esp_hal::spi::Mode as SpiMode;
@@ -33,12 +34,16 @@ pub fn start_timer(
 // ── SPI bus ─────────────────────────────────────────────────────────
 
 /// Initialize SPI2 with DMA and wrap in a shared bus (StaticCell + Mutex).
+///
+/// Generic over pin type so boards with different SPI pin assignments can
+/// share this helper. Any GPIO that implements the esp-hal interconnect
+/// traits (which is every GPIO on the ESP32-S3) can be passed directly.
 pub fn init_spi(
     spi2: esp_hal::peripherals::SPI2<'static>,
     dma_ch0: esp_hal::peripherals::DMA_CH0<'static>,
-    sck: esp_hal::peripherals::GPIO9<'static>,
-    mosi: esp_hal::peripherals::GPIO10<'static>,
-    miso: esp_hal::peripherals::GPIO11<'static>,
+    sck: impl PeripheralOutput<'static>,
+    mosi: impl PeripheralOutput<'static>,
+    miso: impl PeripheralInput<'static>,
 ) -> &'static embassy_sync::mutex::Mutex<NoopRawMutex, SpiBus> {
     let spi = Spi::new(
         spi2,
@@ -66,10 +71,13 @@ pub fn init_spi(
 // ── I2C bus ─────────────────────────────────────────────────────────
 
 /// Initialize I2C0 for peripherals (display, sensors, etc.).
+///
+/// Generic over pin type. I2C lines are bidirectional (open-drain), so both
+/// `PeripheralInput` and `PeripheralOutput` bounds are required.
 pub fn init_i2c(
     i2c0: esp_hal::peripherals::I2C0<'static>,
-    sda: esp_hal::peripherals::GPIO17<'static>,
-    scl: esp_hal::peripherals::GPIO18<'static>,
+    sda: impl PeripheralInput<'static> + PeripheralOutput<'static>,
+    scl: impl PeripheralInput<'static> + PeripheralOutput<'static>,
 ) -> I2cBus {
     I2c::new(i2c0, I2cConfig::default())
         .expect("I2C init")

src/hal/mod.rs

@@ -3,7 +3,7 @@
 //! Each submodule provides low-level bus and peripheral init for one MCU family.
 //! Board files call these with specific pins and construct higher-level drivers.
 
-#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4"))]
+#[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "elecrow_thinknode_m2"))]
 pub mod esp32s3;
 
 #[cfg(any(feature = "rak_wisblock_4631", feature = "wio_tracker_l1"))]

src/host/mod.rs

@@ -6,7 +6,7 @@
 pub mod framing;
 
 cfg_if::cfg_if! {
-    if #[cfg(feature = "heltec_v3_uart")] {
+    if #[cfg(any(feature = "heltec_v3_uart", feature = "elecrow_thinknode_m2"))] {
         mod uart;
         pub use uart::host_task;
     } else {

src/main.rs

@@ -44,7 +44,7 @@ cfg_if::cfg_if! {
     if #[cfg(any(feature = "rak_wisblock_4631", feature = "wio_tracker_l1", feature = "waveshare_rp2040_lora"))] {
         use defmt_rtt as _;
         use panic_probe as _;
-    } else if #[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4"))] {
+    } else if #[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "elecrow_thinknode_m2"))] {
         use esp_backtrace as _;
         use esp_println as _;
     }
@@ -66,7 +66,7 @@ cfg_if::cfg_if! {
         async fn main(spawner: Spawner) {
             run(spawner).await;
         }
-    } else if #[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4"))] {
+    } else if #[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "elecrow_thinknode_m2"))] {
         #[esp_rtos::main]
         async fn main(spawner: Spawner) {
             run(spawner).await;