feat(boards): LilyGo T-Beam S3 Supreme support

ESP32-S3 + SX1262 + SH1106 OLED + AXP2101 PMIC, native USB-C.

The AXP2101 PMIC gates power to the LoRa chip and the OLED. Without
its init sequence (ALDO3 = 3.3 V for LoRa, ALDO1 = 3.3 V for OLED)
the SX1262 never responds on SPI and radio init fails.

Pin map verified against MeshCore's variants/lilygo_tbeam_supreme_SX1262.
PMIC lives on a dedicated I²C1 bus (SDA=42, SCL=41) separate from the
SH1106 on I²C0 (SDA=17, SCL=18); I²C1 is used blocking for a one-shot
init and then dropped. TCXO at 1.6 V via DIO3.

New src/driver/axp.rs holds the AXP2101 init sequence — kept minimal
(only the LoRa + OLED rails), since DongLoRa is a LoRa-over-USB bridge
and every other rail (GPS, BME280, IMU, SD, batt ADC) is out of scope.

CHANGELOG.md

@@ -7,6 +7,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+### Added
+
+- LilyGo T-Beam S3 Supreme board support (ESP32-S3 + SX1262 + SH1106
+  OLED + AXP2101 PMIC, native USB-C).
+  - Pin map verified against MeshCore's
+    `variants/lilygo_tbeam_supreme_SX1262`.
+  - New `src/driver/axp.rs` module with an AXP2101 init sequence
+    (ALDO3 = 3.3 V LoRa, ALDO1 = 3.3 V OLED). The PMIC gates LoRa and
+    display power — without it the SX1262 never responds on SPI.
+  - PMIC lives on a dedicated I²C1 bus (SDA=42, SCL=41), separate
+    from the SH1106 on I²C0 (SDA=17, SCL=18). I²C1 is used blocking
+    for a one-shot init and then dropped.
+  - TCXO driven at 1.6 V via DIO3 (MeshCore uses the same).
+
 ## [1.2.1] - 2026-04-23
 
 ### Fixed

Cargo.toml

@@ -132,6 +132,13 @@ elecrow_thinknode_m2 = [
   "dep:esp-println",
   "dep:esp-rtos",
 ]
+lilygo_tbeam_supreme = [
+  "embassy",
+  "dep:esp-backtrace",
+  "dep:esp-hal",
+  "dep:esp-println",
+  "dep:esp-rtos",
+]
 rak_wisblock_4631 = [
   "embassy",
   "dep:cortex-m",

README.md

@@ -24,6 +24,7 @@ All commands are run from the `firmware/` directory.
 | 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 |
+| LilyGo T-Beam S3 Supreme | `lilygo_tbeam_supreme` | ESP32-S3 | SX1262 | Native CDC-ACM | 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

@@ -10,6 +10,7 @@ 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"
+lilygo_tbeam_supreme := "lilygo_tbeam_supreme 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"
@@ -18,7 +19,7 @@ builds_dir := "builds"
 version := `sed -n 's/^version = "\(.*\)"/\1/p' Cargo.toml`
 
 # All known boards
-boards := "heltec_v3 heltec_v3_uart heltec_v4 elecrow_thinknode_m2 rak_wisblock_4631 waveshare_rp2040_lora wio_tracker_l1"
+boards := "heltec_v3 heltec_v3_uart heltec_v4 elecrow_thinknode_m2 lilygo_tbeam_supreme rak_wisblock_4631 waveshare_rp2040_lora wio_tracker_l1"
 
 # Install all required tools and toolchains
 setup:
@@ -214,6 +215,7 @@ _info name:
      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}}" == "lilygo_tbeam_supreme" ]; then echo "{{lilygo_tbeam_supreme}}"; \
      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/lilygo_tbeam_supreme.rs

@@ -0,0 +1,153 @@
+//! LilyGo T-Beam S3 Supreme — ESP32-S3 + SX1262 + SH1106 OLED + AXP2101 PMIC.
+//!
+//! Big-brother of the classic T-Beam: ESP32-S3-WROOM-1 module, SX1262 with a
+//! TCXO, 128×64 SH1106 OLED, AXP2101 PMIC on a dedicated I²C1 bus. Native USB
+//! (no UART bridge chip).
+//!
+//! The AXP2101 gates power to the SX1262 and OLED. Without its init sequence
+//! the LoRa chip never responds on SPI and `LoRa::new` fails.
+//!
+//! Pin map (verified from MeshCore variants/lilygo_tbeam_supreme_SX1262/):
+//!   LoRa SPI: SCK=12, MOSI=11, MISO=13, CS=10
+//!   LoRa ctl: RESET=5, DIO1=1, BUSY=4 (TCXO @ 1.6 V via DIO3)
+//!   OLED I²C: SDA=17, SCL=18, SH1106 @ 0x3C (I²C0)
+//!   PMIC I²C: SDA=42, SCL=41, AXP2101 @ 0x34 (I²C1, blocking, PMIC-only)
+//!   USB:      native USB-C on GPIO19/20 (fixed ESP32-S3 D+/D-)
+//!   LED:      GPIO6 (active HIGH indicator, reuses MeshCore's P_LORA_TX_LED)
+//!
+//! GPS / battery / IMU / SD / BME280 are unused — DongLoRa is a transparent
+//! LoRa-over-USB bridge. The PMIC init only enables ALDO1 (OLED) and ALDO3
+//! (LoRa); other rails are left at their AXP2101 power-on defaults.
+
+use esp_hal::gpio::{Level, Output, OutputConfig};
+use esp_hal::i2c::master::{Config as I2cConfig, I2c};
+use static_cell::StaticCell;
+
+use super::esp32s3;
+use super::traits::{BoardParts, LoRaBoard};
+use crate::driver::axp;
+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 UsbDriver = esp_hal::otg_fs::asynch::Driver<'static>;
+pub type LedDriver = SimpleLed<Output<'static>>;
+
+// ── Peripheral bundles ──────────────────────────────────────────────
+
+pub struct UsbParts {
+    pub driver: UsbDriver,
+}
+
+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 = "LilyGo T-Beam S3 Supreme";
+    const TX_POWER_RANGE: (i8, i8) = (-9, 22);
+
+    type RadioParts = RadioParts;
+    type CommParts = UsbParts;
+    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, UsbParts, DisplayParts, LedDriver> {
+        let p = self.p;
+
+        mcu::start_timer(p.TIMG0, p.SW_INTERRUPT);
+
+        // AXP2101 PMIC on I²C1 (SDA=42, SCL=41). Blocking, one-shot: we only
+        // need to flip the LoRa/OLED rails on, then the bus can be dropped.
+        // If this fails the LoRa chip stays unpowered — log and keep going so
+        // the rest of the boot path can still produce diagnostics.
+        {
+            let mut pmic = I2c::new(p.I2C1, I2cConfig::default())
+                .expect("I2C1 init")
+                .with_sda(p.GPIO42)
+                .with_scl(p.GPIO41);
+            if let Err(_e) = axp::axp2101_init_lora_oled(&mut pmic) {
+                defmt::error!("AXP2101 init failed — LoRa rail may be dead");
+            }
+        }
+        // Let ALDO1/ALDO3 settle before touching the LoRa SPI or OLED I²C.
+        esp_hal::delay::Delay::new().delay_millis(20);
+
+        // 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=5, DIO1=1, BUSY=4, TCXO @ 1.6 V via DIO3.
+        let radio = esp32s3::init_radio(
+            spi_bus,
+            p.GPIO10,
+            p.GPIO5,
+            p.GPIO1,
+            p.GPIO4,
+            lora_phy::sx126x::TcxoCtrlVoltage::Ctrl1V6,
+        );
+
+        // Native USB-C on GPIO19/20. Switches the internal USB PHY from
+        // Serial-JTAG to OTG.
+        let usb_inst = esp_hal::otg_fs::Usb::new(p.USB0, p.GPIO20, p.GPIO19);
+        static EP_OUT_BUF: StaticCell<[u8; 1024]> = StaticCell::new();
+        let ep_out_buf = EP_OUT_BUF.init([0u8; 1024]);
+        let host = UsbParts {
+            driver: esp_hal::otg_fs::asynch::Driver::new(
+                usb_inst,
+                ep_out_buf,
+                esp_hal::otg_fs::asynch::Config::default(),
+            ),
+        };
+
+        // I2C0 for SH1106 OLED: SDA=17, SCL=18 (async, handed to display task).
+        let i2c = mcu::init_i2c(p.I2C0, p.GPIO17, p.GPIO18);
+        let display = Some(DisplayParts { i2c });
+
+        // Activity 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/driver/axp.rs

@@ -0,0 +1,64 @@
+//! AXP PMIC init — turn on the rails that feed LoRa and the OLED.
+//!
+//! T-Beam–class boards gate LoRa, OLED (and GPS/sensors, which this firmware
+//! does not use) through an X-Powers PMIC on I²C. Until the PMIC is told to
+//! enable the right LDOs/DCDCs, the SX126x/SX127x chip sits unpowered and
+//! `LoRa::new` fails. This module's only job is to flip those switches.
+//!
+//! Two PMICs are covered:
+//!
+//! * [`axp2101_init_lora_oled`] — LilyGo T-Beam S3 Supreme. ALDO3 = 3.3 V
+//!   feeds the SX1262; ALDO1 = 3.3 V feeds the SH1106 OLED. Both live on a
+//!   dedicated I²C1 bus (separate from the display).
+//! * [`axp192_init_lora_oled`] — LilyGo T-Beam (classic). LDO2 = 3.3 V feeds
+//!   the SX1276; DCDC1 = 3.3 V feeds the SSD1306 OLED. PMIC shares the
+//!   display I²C bus.
+//!
+//! Everything unrelated to LoRa + OLED (GPS, sensors, SD, batt ADC) is left
+//! alone. Out-of-scope for a transparent LoRa-over-USB bridge.
+//!
+//! Init is blocking on purpose. It runs once during `into_parts`, which is a
+//! synchronous function called before task spawning. Using the blocking
+//! `embedded_hal` trait keeps the PMIC wiring out of the async machinery and
+//! lets the caller drop the I²C bus immediately after init (no bus handoff).
+
+use embedded_hal::i2c::I2c;
+
+/// Both chips respond at this 7-bit I²C address.
+const PMIC_ADDR: u8 = 0x34;
+
+// ── AXP2101 (T-Beam S3 Supreme) ──────────────────────────────────────
+
+/// LDO on/off control register. Bits:
+///   0 = ALDO1, 1 = ALDO2, 2 = ALDO3, 3 = ALDO4, 4 = BLDO1, 5 = BLDO2.
+const AXP2101_REG_LDO_ONOFF: u8 = 0x90;
+/// ALDO1 voltage register (OLED rail on T-Beam Supreme).
+const AXP2101_REG_ALDO1_V: u8 = 0x92;
+/// ALDO3 voltage register (LoRa rail on T-Beam Supreme).
+const AXP2101_REG_ALDO3_V: u8 = 0x94;
+
+/// Voltage code for 3.3 V on ALDOx: 0.5 V + 28 × 100 mV.
+const AXP2101_V_3V3: u8 = 28;
+
+/// Mask enabling ALDO1 + ALDO3 in [`AXP2101_REG_LDO_ONOFF`].
+const AXP2101_ALDO1_ALDO3: u8 = 0b0000_0101;
+
+/// Bring up LoRa (ALDO3) and OLED (ALDO1) rails at 3.3 V.
+///
+/// Voltage registers are set before the enable bits to avoid glitching the
+/// rails through the reset-default voltage. Other rails are left untouched
+/// (read-modify-write on the enable register) so any board-specific OTP
+/// defaults stay intact.
+pub fn axp2101_init_lora_oled<I: I2c>(i2c: &mut I) -> Result<(), I::Error> {
+    i2c.write(PMIC_ADDR, &[AXP2101_REG_ALDO3_V, AXP2101_V_3V3])?;
+    i2c.write(PMIC_ADDR, &[AXP2101_REG_ALDO1_V, AXP2101_V_3V3])?;
+
+    let mut onoff = [0u8; 1];
+    i2c.write_read(PMIC_ADDR, &[AXP2101_REG_LDO_ONOFF], &mut onoff)?;
+    i2c.write(
+        PMIC_ADDR,
+        &[AXP2101_REG_LDO_ONOFF, onoff[0] | AXP2101_ALDO1_ALDO3],
+    )?;
+
+    Ok(())
+}

src/driver/mod.rs

@@ -1,11 +1,19 @@
-#[cfg(any(feature = "wio_tracker_l1", feature = "elecrow_thinknode_m2"))]
+#[cfg(any(
+    feature = "wio_tracker_l1",
+    feature = "elecrow_thinknode_m2",
+    feature = "lilygo_tbeam_supreme"
+))]
 pub mod sh1106;
 
+#[cfg(feature = "lilygo_tbeam_supreme")]
+pub mod axp;
+
 #[cfg(any(
     feature = "heltec_v3",
     feature = "heltec_v3_uart",
     feature = "heltec_v4",
     feature = "elecrow_thinknode_m2",
+    feature = "lilygo_tbeam_supreme",
     feature = "wio_tracker_l1",
     feature = "waveshare_rp2040_lora"
 ))]
@@ -51,7 +59,11 @@ where
     }
 }
 
-#[cfg(any(feature = "wio_tracker_l1", feature = "elecrow_thinknode_m2"))]
+#[cfg(any(
+    feature = "wio_tracker_l1",
+    feature = "elecrow_thinknode_m2",
+    feature = "lilygo_tbeam_supreme"
+))]
 impl<I> DisplayBrightness for sh1106::Sh1106<I>
 where
     I: embedded_hal_async::i2c::I2c,

src/hal/mod.rs

@@ -7,7 +7,8 @@
     feature = "heltec_v3",
     feature = "heltec_v3_uart",
     feature = "heltec_v4",
-    feature = "elecrow_thinknode_m2"
+    feature = "elecrow_thinknode_m2",
+    feature = "lilygo_tbeam_supreme"
 ))]
 pub mod esp32s3;
 

src/main.rs

@@ -48,7 +48,7 @@ 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", feature = "elecrow_thinknode_m2"))] {
+    } else if #[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "elecrow_thinknode_m2", feature = "lilygo_tbeam_supreme"))] {
         use esp_backtrace as _;
         use esp_println as _;
     }
@@ -72,7 +72,7 @@ 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", feature = "elecrow_thinknode_m2"))] {
+    } else if #[cfg(any(feature = "heltec_v3", feature = "heltec_v3_uart", feature = "heltec_v4", feature = "elecrow_thinknode_m2", feature = "lilygo_tbeam_supreme"))] {
         #[esp_rtos::main]
         async fn main(spawner: Spawner) {
             run(spawner).await;