修复 moonshine NRF52 启动: LFRC + S140 v7 + 禁用 I2C

RF-BM-ND05 无 32.768kHz 晶振,USE_LFXO 导致 SoftDevice 卡在
RTC1_IRQHandler,BLE 静默失败。改用 USE_LFRC。

P0.09/P0.10 是 NFC 引脚,被模块内部电路拉低,TWIM endTransmission
无限等待。禁用 I2C 及依赖功能(环境传感器/输入代理/加速度计/磁力计)。

linker 改用 nrf52840_s140_v7.ld 匹配仓库打包的 S140 v7.3.0
SoftDevice(app @ 0x27000)。readme 补充 OpenOCD SWD 烧录流程。

variants/nrf52840/diy/moonshine_NRF52/platformio.ini

@@ -2,8 +2,15 @@
 [env:moonshine_NRF52_node]
 extends = nrf52840_base
 board = adafruit_feather_nrf52840
+board_build.ldscript = src/platform/nrf52/nrf52840_s140_v7.ld
 build_flags = ${nrf52840_base.build_flags}
   -I variants/nrf52840/diy/moonshine_NRF52
   -D PRIVATE_HW
+  -D USE_SEGGER
+  -D MESHTASTIC_EXCLUDE_I2C=1
+  -D MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR=1
+  -D MESHTASTIC_EXCLUDE_INPUTBROKER=1
+  -D MESHTASTIC_EXCLUDE_ACCELEROMETER=1
+  -D MESHTASTIC_EXCLUDE_MAGNETOMETER=1
 build_src_filter = ${nrf52_base.build_src_filter} +<../variants/nrf52840/diy/moonshine_NRF52>
 debug_tool = jlink

variants/nrf52840/diy/moonshine_NRF52/readme.md

@@ -5,7 +5,9 @@ DIY Meshtastic node variant based on the RF-BM-ND05 nRF52840 module.
 ## Hardware
 
 - **MCU module**: RF-BM-ND05 (nRF52840, 512 KB flash / 128 KB RAM)
-- **LF clock**: 32.768 kHz crystal (`USE_LFXO`)
+- **LF clock**: internal RC (`USE_LFRC`) - RF-BM-ND05 has no 32.768 kHz crystal; using
+  `USE_LFXO` without a crystal makes SoftDevice hang in `RTC1_IRQHandler` waiting
+  for LFCLK, causing LED-stuck-on and silent BLE failure.
 - **LoRa**: multi-module compatible (SX1262 / SX1268 / RF95 / LLCC68 / LR1121 / LR2021) with TCXO
 - **GPS**: u-blox (no EN pin)
 - **Battery ADC**: 0.5 voltage divider (equal resistors)
@@ -51,4 +53,57 @@ pio run -e moonshine_NRF52_node
 ```
 
 Uses `PRIVATE_HW` (HardwareModel 255) - no protobuf or `architecture.h` changes
-required. Flash via SWD (`debug_tool = jlink`).
+required.
+
+The build links against `nrf52840_s140_v7.ld`, so the application is linked to
+start at `0x27000` and requires the S140 SoftDevice v7.x to be present on the
+chip at `0x0`-`0x26FFF`. The build output (`firmware-*.hex` / `.uf2`) contains
+**only the application**, not the SoftDevice.
+
+## Flash (first time on a bare RF-BM-ND05)
+
+A factory-fresh RF-BM-ND05 module has **no SoftDevice and no bootloader**. The
+SoftDevice must be flashed once via SWD before the application; otherwise
+`Bluefruit.begin()` fails, `sd_flash_*` calls (LittleFS, NodeDB, config
+persistence) return errors, and the node appears dead.
+
+The S140 v7.3.0 SoftDevice hex is shipped in this repo at
+`bin/s140_nrf52_7.3.0_softdevice.hex`. Flash via SWD with OpenOCD (CMSIS-DAP /
+J-Link / ST-Link). The `nrf52_recover` command does a chip-wide ERASEALL through
+the nRF52 CTRL-AP and clears APPROTECT, so it is the recommended first step on a
+fresh module (ebyte/Raytac modules ship with APPROTECT engaged).
+
+```sh
+# Single-command flow: recover (erase all + unlock) -> SoftDevice -> app -> reset
+C:/openocd/bin/openocd.exe -s C:/openocd/share/openocd/scripts \
+  -f interface/cmsis-dap.cfg -f target/nrf52.cfg \
+  -c "init; nrf52_recover; \
+      program bin/s140_nrf52_7.3.0_softdevice.hex verify; \
+      program .pio/build/moonshine_NRF52_node/firmware-moonshine_NRF52_node-*.hex verify; \
+      reset run; exit"
+```
+
+If the chip is already unlocked and you only need to re-flash the application
+(SoftDevice already present), skip `nrf52_recover` and the SoftDevice line:
+
+```sh
+C:/openocd/bin/openocd.exe -s C:/openocd/share/openocd/scripts \
+  -f interface/cmsis-dap.cfg -f target/nrf52.cfg \
+  -c "init; \
+      program .pio/build/moonshine_NRF52_node/firmware-moonshine_NRF52_node-*.hex verify; \
+      reset run; exit"
+```
+
+Notes:
+- The firmware hex filename contains a commit hash (e.g. `2.8.0.421838f`); use
+  the actual file produced by `pio run` or a shell glob.
+- The SoftDevice hex occupies `0x0`-`0x26498` (~156 KB) and does **not** write
+  UICR, so `nrf52_recover` is safe (UICR resets to defaults).
+- Swap `interface/cmsis-dap.cfg` for `interface/jlink.cfg` or
+  `interface/stlink.cfg` if using a different SWD probe.
+
+No UF2 bootloader is installed in this flow, so subsequent updates must go
+through BLE DFU (secure DFU service) or SWD again. To enable UF2 drag-and-drop
+updates, flash an Adafruit nRF52 UF2 bootloader
+(https://github.com/adafruit/Adafruit_nRF52_Bootloader) at `0x0` in place of the
+bare SoftDevice - the bootloader bundles its own SoftDevice.

variants/nrf52840/diy/moonshine_NRF52/variant.h

@@ -4,7 +4,8 @@
 /** Master clock frequency */
 #define VARIANT_MCK (64000000ul)
 
-#define USE_LFXO // Board uses 32khz crystal for LF
+// #define USE_LFXO // Board uses 32khz crystal for LF
+#define USE_LFRC // RF-BM-ND05 has no LFXO crystal - use internal RC
 
 /*----------------------------------------------------------------------------
  *        Headers