nice!nano board support (#1499)

machine/nice\!nano: add board support

src/machine/board_nicenano.go

@@ -0,0 +1,84 @@
+// +build nicenano
+
+package machine
+
+const HasLowFrequencyCrystal = true
+
+// GPIO Pins
+const (
+	D006 = P0_06
+	D008 = P0_08
+	D017 = P0_17
+	D020 = P0_20
+	D022 = P0_22
+	D024 = P0_24
+	D100 = P1_00
+	D011 = P0_11
+	D104 = P1_04
+	D106 = P1_06
+
+	D004 = P0_04 // AIN2; P0.04 (AIN2) is used to read the voltage of the battery via ADC. It can’t be used for any other function.
+	D013 = P0_13 // VCC 3.3V; P0.13 on VCC shuts off the power to VCC when you set it to high; This saves on battery immensely for LEDs of all kinds that eat power even when off
+	D115 = P1_15
+	D113 = P1_13
+	D031 = P0_31 // AIN7
+	D029 = P0_29 // AIN5
+	D002 = P0_02 // AIN0
+
+	D111 = P1_11
+	D010 = P0_10 // NFC2
+	D009 = P0_09 // NFC1
+
+	D026 = P0_26
+	D012 = P0_12
+	D101 = P1_01
+	D102 = P1_02
+	D107 = P1_07
+)
+
+// Analog Pins
+const (
+	AIN2 = P0_04 // Battery
+	AIN7 = P0_31
+	AIN5 = P0_29
+	AIN0 = P0_02
+)
+
+const (
+	LED = P0_15
+)
+
+// UART0 pins (logical UART1)
+const (
+	UART_RX_PIN = P0_06
+	UART_TX_PIN = P0_08
+)
+
+// UART0 is the USB device
+var (
+	UART0 = USB
+)
+
+// I2C pins
+const (
+	SDA_PIN = P0_17 // I2C0 external
+	SCL_PIN = P0_20 // I2C0 external
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = P0_22 // SCK
+	SPI0_SDO_PIN = P0_24 // SDO
+	SPI0_SDI_PIN = P1_00 // SDI
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "nice!nano"
+	usb_STRING_MANUFACTURER = "Nice Keyboards"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x0029
+)