Add support for RAK815 board from here:

https://store.rakwireless.com/products/rak815-hybrid-location-tracker

src/boards/rak815/board.h

@@ -0,0 +1,62 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Ha Thach for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef _RAK815_H
+#define _RAK815_H
+
+/*------------------------------------------------------------------*/
+/* LED
+ *------------------------------------------------------------------*/
+#define LEDS_NUMBER        4
+#define LED_PRIMARY_PIN    28
+#define LED_SECONDARY_PIN  29
+#define LED_STATE_ON       1
+
+/*------------------------------------------------------------------*/
+/* BUTTON
+ *------------------------------------------------------------------*/
+#define BUTTONS_NUMBER     2
+#define BUTTON_1           27
+#define BUTTON_2           24
+#define BUTTON_PULL        NRF_GPIO_PIN_PULLUP
+
+/*------------------------------------------------------------------*/
+/* UART (only used by nRF52832)
+ *------------------------------------------------------------------*/
+#define RX_PIN_NUMBER      28
+#define TX_PIN_NUMBER      29
+#define CTS_PIN_NUMBER     0
+#define RTS_PIN_NUMBER     0
+#define HWFC               false
+
+//--------------------------------------------------------------------+
+// BLE OTA
+//--------------------------------------------------------------------+
+#define BLEDIS_MANUFACTURER "RAK"
+#define BLEDIS_MODEL        "RAK815"
+
+#define UF2_PRODUCT_NAME    "RAK815"
+#define UF2_INDEX_URL       "https://store.rakwireless.com/products/rak815-hybrid-location-tracker"
+
+#endif // _RAK815_H

src/boards/rak815/board.mk

@@ -0,0 +1,2 @@
+# nrf52 is nrf52832
+MCU_SUB_VARIANT = nrf52