Add a rak4631 board definition testing

examples/MultiDevice/boards/rak4631.json

@@ -0,0 +1,52 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "nrf52840_s140_v6.ld"
+    },
+    "core": "nRF5",
+    "cpu": "cortex-m4",
+    "extra_flags": "-DARDUINO_WISCORE_RAK4631_BOARD -DNRF52840_XXAA",
+    "f_cpu": "64000000L",
+    "hwids": [
+      ["0x239A", "0x8029"],
+      ["0x239A", "0x0029"],
+      ["0x239A", "0x002A"],
+      ["0x239A", "0x802A"]
+    ],
+    "usb_product": "WisCore RAK4631 Board",
+    "mcu": "nrf52840",
+    "variant": "wiscore_rak4631",
+    "bsp": {
+      "name": "adafruit"
+    },
+    "softdevice": {
+      "sd_flags": "-DS140",
+      "sd_name": "s140",
+      "sd_version": "6.1.1",
+      "sd_fwid": "0x00B6"
+    },
+    "bootloader": {
+      "settings_addr": "0xFF000"
+    }
+  },
+  "connectivity": ["bluetooth"],
+  "debug": {
+    "jlink_device": "nRF52840_xxAA",
+    "svd_path": "nrf52840.svd",
+    "openocd_target": "nrf52.cfg"
+  },
+  "frameworks": ["arduino"],
+  "name": "WisCore RAK4631 Board",
+  "upload": {
+    "maximum_ram_size": 235520,
+    "maximum_size": 815104,
+    "speed": 115200,
+    "protocol": "nrfutil",
+    "protocols": ["jlink", "nrfjprog", "nrfutil", "stlink"],
+    "use_1200bps_touch": true,
+    "require_upload_port": true,
+    "wait_for_upload_port": true
+  },
+  "url": "https://www.rakwireless.com",
+  "vendor": "RAKwireless"
+}

examples/MultiDevice/platformio.ini

@@ -1,3 +1,7 @@
+[platformio]
+src_dir = src
+boards_dir = boards
+
 [env]
 lib_extra_dirs = ../..
 
@@ -20,6 +24,17 @@ framework = arduino
 monitor_speed = 115200
 build_flags = -DCFG_DEBUG=0
 
+; RAKwireless RAK4630 (WisBlock) — nRF52840 with Bluefruit backend.
+; Board definition lives in boards/rak4631.json (always available).
+[env:rak4630]
+platform = nordicnrf52
+platform_packages = framework-arduinoadafruitnrf52 @ 1.10700.0
+framework = arduino
+board = rak4631
+monitor_speed = 115200
+upload_protocol = nrfutil
+build_flags = -DCFG_DEBUG=0
+
 [env:esp32dev]
 platform = espressif32
 board = esp32dev