Adding support for the Arduino Zero (#1365)

* machine/arduino-zero: adding support for Arduino Zero

Co-authored-by: Ayke
Co-authored-by: Jack Reamy

README.md

@@ -43,7 +43,7 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for
 
 You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.
 
-The following 40 microcontroller boards are currently supported:
+The following 41 microcontroller boards are currently supported:
 
 * [Adafruit Circuit Playground Bluefruit](https://www.adafruit.com/product/4333)
 * [Adafruit Circuit Playground Express](https://www.adafruit.com/product/3333)
@@ -62,6 +62,7 @@ The following 40 microcontroller boards are currently supported:
 * [Arduino Mega 2560](https://store.arduino.cc/arduino-mega-2560-rev3)
 * [Arduino Nano](https://store.arduino.cc/arduino-nano)
 * [Arduino Nano33 IoT](https://store.arduino.cc/nano-33-iot)
+* [Arduino Zero](https://store.arduino.cc/usa/arduino-zero)
 * [Arduino Uno](https://store.arduino.cc/arduino-uno-rev3)
 * [BBC micro:bit](https://microbit.org/)
 * [Digispark](http://digistump.com/products/1)

src/machine/board_arduino_zero.go

@@ -0,0 +1,101 @@
+// +build sam,atsamd21,arduino_zero
+
+package machine
+
+// used to reset into bootloader
+const RESET_MAGIC_VALUE = 0x07738135
+
+// GPIO Pins - Digital Low
+const (
+	D0 = PA11 // RX
+	D1 = PA10 // TX
+	D2 = PA14
+	D3 = PA09 // PWM available
+	D4 = PA08 // PWM available
+	D5 = PA15 // PWM available
+	D6 = PA20 // PWM available
+	D7 = PA21
+)
+
+// GPIO Pins - Digital High
+const (
+	D8  = PA06 // PWM available
+	D9  = PA07 // PWM available
+	D10 = PA18 // PWM available
+	D11 = PA16 // PWM available
+	D12 = PA19 // PWM available
+	D13 = PA17 // PWM available
+)
+
+// LEDs on the Arduino Zero
+const (
+	LED      = LED1
+	LED1 Pin = D13
+	LED2 Pin = PA27 // TX LED
+	LED3 Pin = PB03 // RX LED
+)
+
+// ADC pins
+const (
+	AREF Pin = PA03
+	ADC0 Pin = PA02
+	ADC1 Pin = PB08
+	ADC2 Pin = PB09
+	ADC3 Pin = PA04
+	ADC4 Pin = PA05
+	ADC5 Pin = PB02
+)
+
+// SPI pins - EDBG connected
+const (
+	SPI0_SDO_PIN Pin = PA16 // MOSI: SERCOM1/PAD[0]
+	SPI0_SDI_PIN Pin = PA19 // MISO: SERCOM1/PAD[2]
+	SPI0_SCK_PIN Pin = PA17 // SCK:  SERCOM1/PAD[3]
+)
+
+// SPI pins (Legacy ICSP)
+const (
+	SPI1_SDO_PIN Pin = PB10 // MOSI: SERCOM4/PAD[2] - Pin 4
+	SPI1_SDI_PIN Pin = PA12 // MISO: SERCOM4/PAD[0] - Pin 1
+	SPI1_SCK_PIN Pin = PB11 // SCK:  SERCOM4/PAD[3] - Pin 3
+)
+
+// I2C pins - EDBG connected
+const (
+	SDA_PIN Pin = PA22 // SDA: SERCOM3/PAD[0] - Pin 20
+	SCL_PIN Pin = PA23 // SCL: SERCOM3/PAD[1] - Pin 21
+)
+
+// I2S pins - might not be exposed
+const (
+	I2S_SCK_PIN Pin = PA10
+	I2S_SD_PIN  Pin = PA07
+	I2S_WS_PIN  Pin = PA11
+)
+
+// UART0 pins - EDBG connected
+const (
+	UART_RX_PIN Pin = D0
+	UART_TX_PIN Pin = D1
+)
+
+// 'native' USB port pins
+const (
+	USBCDC_DM_PIN Pin = PA24
+	USBCDC_DP_PIN Pin = PA25
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Arduino Zero"
+	usb_STRING_MANUFACTURER = "Arduino LLC"
+
+	usb_VID uint16 = 0x2341
+	usb_PID uint16 = 0x804d
+)
+
+// 32.768 KHz Crystal
+const (
+	XIN32  Pin = PA00
+	XOUT32 Pin = PA01
+)

targets/arduino-zero.json

@@ -0,0 +1,6 @@
+{
+    "inherits": ["atsamd21g18a"],
+    "build-tags": ["sam", "atsamd21g18a", "arduino_zero"],
+    "flash-command": "bossac -i -e -w -v -R -U --port={port} --offset=0x2000 {bin}",
+    "flash-1200-bps-reset": "true"
+}