WIP: get Heltec V3 working

src/board/esp32s3.rs

@@ -28,8 +28,12 @@ type Iv = GenericSx126xInterfaceVariant<Output<'static>, Input<'static>>;
 type RadioSpiDevice = SpiDevice<'static, NoopRawMutex, SpiBus, Nss>;
 pub type RadioDriver = Sx126x<RadioSpiDevice, Iv, Sx1262>;
 
+#[cfg(not(feature = "heltec_v3"))]
 pub type UsbDriver = esp_hal::otg_fs::asynch::Driver<'static>;
 
+#[cfg(feature = "heltec_v3")]
+pub type UartDriver = esp_hal::uart::Uart<'static, esp_hal::Async>;
+
 pub type DisplayI2c = I2c<'static, esp_hal::Async>;
 
 // ── Peripheral bundles ───────────────────────────────────────────────
@@ -39,10 +43,16 @@ pub struct RadioParts {
     pub delay: Delay,
 }
 
+#[cfg(not(feature = "heltec_v3"))]
 pub struct UsbParts {
     pub driver: UsbDriver,
 }
 
+#[cfg(feature = "heltec_v3")]
+pub struct UartParts {
+    pub driver: UartDriver,
+}
+
 pub struct DisplayParts {
     pub i2c: DisplayI2c,
     pub mac: [u8; 6],
@@ -107,7 +117,7 @@ pub fn init_radio(
 
     let sx_config = sx126x::Config {
         chip: Sx1262,
-        tcxo_ctrl: Some(sx126x::TcxoCtrlVoltage::Ctrl1V7),
+        tcxo_ctrl: Some(sx126x::TcxoCtrlVoltage::Ctrl1V8),
         use_dcdc: true,
         rx_boost: false,
     };
@@ -118,6 +128,7 @@ pub fn init_radio(
     }
 }
 
+#[cfg(not(feature = "heltec_v3"))]
 /// Initialize USB OTG CDC-ACM driver.
 pub fn init_usb(
     usb0: esp_hal::peripherals::USB0<'static>,
@@ -136,6 +147,24 @@ pub fn init_usb(
     }
 }
 
+#[cfg(feature = "heltec_v3")]
+/// Initialize UART0 for boards with USB-UART bridge chips (e.g. CP2102).
+pub fn init_uart(
+    uart0: esp_hal::peripherals::UART0<'static>,
+    tx: esp_hal::peripherals::GPIO43<'static>,
+    rx: esp_hal::peripherals::GPIO44<'static>,
+) -> UartParts {
+    use esp_hal::uart::{Config as UartConfig, Uart};
+
+    let uart = Uart::new(uart0, UartConfig::default())
+        .expect("UART init")
+        .with_tx(tx)
+        .with_rx(rx)
+        .into_async();
+
+    UartParts { driver: uart }
+}
+
 /// Initialize I2C bus for display.
 pub fn init_display_i2c(
     i2c0: esp_hal::peripherals::I2C0<'static>,

src/board/heltec_v3.rs

@@ -3,8 +3,8 @@ use esp_hal::gpio::{Level, Output, OutputConfig};
 use super::esp32s3;
 use super::traits::LoRaBoard;
 
-#[allow(unused_imports)] // Re-exported for other modules (display, radio, usb tasks)
-pub use super::esp32s3::{DisplayI2c, DisplayParts, RadioDriver, RadioParts, UsbDriver, UsbParts};
+#[allow(unused_imports)] // Re-exported for other modules (display, radio, uart tasks)
+pub use super::esp32s3::{DisplayI2c, DisplayParts, RadioDriver, RadioParts, UartDriver, UartParts};
 
 // ── Board init ───────────────────────────────────────────────────────
 
@@ -27,23 +27,31 @@ impl LoRaBoard for Board {
 }
 
 impl Board {
-    pub fn into_parts(self) -> (RadioParts, UsbParts, Option<DisplayParts>) {
+    pub fn into_parts(self) -> (RadioParts, UartParts, Option<DisplayParts>) {
         let p = self.p;
 
         esp32s3::start_timer(p.TIMG0);
 
-        // Vext power: GPIO21, active LOW to enable OLED
-        let vext = Output::new(p.GPIO21, Level::Low, OutputConfig::default());
+        // Vext power: GPIO36, active LOW to enable peripherals
+        let vext = Output::new(p.GPIO36, Level::Low, OutputConfig::default());
         core::mem::forget(vext); // hold pin low permanently; drop would reset it
 
         let radio = esp32s3::init_radio(
             p.SPI2, p.DMA_CH0, p.GPIO9, p.GPIO10, p.GPIO11, p.GPIO8, p.GPIO12, p.GPIO14, p.GPIO13,
         );
-        let usb = esp32s3::init_usb(p.USB0, p.GPIO20, p.GPIO19);
+        let uart = esp32s3::init_uart(p.UART0, p.GPIO43, p.GPIO44);
+
+        // SSD1306 display reset: pulse GPIO21 low->high before I2C init
+        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); // hold reset high permanently
+
         let i2c = esp32s3::init_display_i2c(p.I2C0, p.GPIO17, p.GPIO18);
         let mac = Self::mac_address();
         let display = Some(DisplayParts { i2c, mac });
 
-        (radio, usb, display)
+        (radio, uart, display)
     }
 }

src/board/rak_wisblock_4631.rs

@@ -112,7 +112,7 @@ impl Board {
 
         let sx_config = sx126x::Config {
             chip: Sx1262,
-            tcxo_ctrl: Some(sx126x::TcxoCtrlVoltage::Ctrl1V7),
+            tcxo_ctrl: Some(sx126x::TcxoCtrlVoltage::Ctrl1V8),
             use_dcdc: true,
             rx_boost: false,
         };