add board: RAKwireless RAK4631

GNUmakefile

@@ -642,6 +642,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=xiao                examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=rak4631             examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/dac
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/dac

src/machine/board_rak4631.go

@@ -0,0 +1,86 @@
+//go:build rak4631
+
+package machine
+
+const HasLowFrequencyCrystal = true
+
+// Digital Pins
+const (
+	D0 Pin = P0_28
+	D1 Pin = P0_02
+)
+
+// Analog pins
+const (
+	A0 Pin = P0_17
+	A1 Pin = P1_02
+	A2 Pin = P0_21
+)
+
+// Onboard LEDs
+const (
+	LED  = LED2
+	LED1 = P1_03
+	LED2 = P1_04
+)
+
+// UART pins
+const (
+	// Default to UART1
+	UART_RX_PIN = UART0_RX_PIN
+	UART_TX_PIN = UART0_TX_PIN
+
+	// UART1
+	UART0_RX_PIN = P0_19
+	UART0_TX_PIN = P0_20
+
+	// UART2
+	UART1_RX_PIN = P0_15
+	UART1_TX_PIN = P0_16
+)
+
+// I2C pins
+const (
+	SDA_PIN = SDA1_PIN
+	SCL_PIN = SCL1_PIN
+
+	SDA1_PIN = P0_13
+	SCL1_PIN = P0_14
+
+	SDA2_PIN = P0_24
+	SCL2_PIN = P0_25
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = P0_03
+	SPI0_SDO_PIN = P0_29
+	SPI0_SDI_PIN = P0_30
+)
+
+// Peripherals
+const (
+	LORA_NSS    = P1_10
+	LORA_SCK    = P1_11
+	LORA_MOSI   = P1_12
+	LORA_MISO   = P1_13
+	LORA_BUSY   = P1_14
+	LORA_DIO1   = P1_15
+	LORA_NRESET = P1_06
+	LORA_POWER  = P1_05
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "WisCore RAK4631 Board"
+	usb_STRING_MANUFACTURER = "RAKwireless"
+)
+
+var (
+	usb_VID uint16 = 0x239a
+	usb_PID uint16 = 0x8029
+)
+
+var (
+	DefaultUART = UART0
+)

targets/rak4631.json

@@ -0,0 +1,6 @@
+{
+	"inherits": ["nrf52840", "nrf52840-s140v6-uf2"],
+	"build-tags": ["rak4631"],
+	"serial-port": ["239a:8029"],
+	"msd-volume-name": ["RAK4631"]
+}