Arduino/Genuino Zero

Overview

The Arduino Zero is a maker-friendly development board with Atmel’s Embedded Debugger (EDBG), which provides a full debug interface without the need for additional hardware.

Hardware

  • ATSAMD21G18A ARM Cortex-M0+ processor at 48 MHz

  • 32.768 kHz crystal oscillator

  • 256 KiB flash memory and 32 KiB of RAM

  • 3 user LEDs

  • One reset button

  • On-board USB based EDBG unit with serial console

  • Native USB port

Supported Features

The arduino_zero board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.
arduino_zero
/
samd21g18a

Type

Location

Description

Compatible

CPU

on-chip

ARM Cortex-M0+ CPU1

arm,cortex-m0+

ADC

on-chip

Atmel SAM0 family ADC1

atmel,sam0-adc

ARM architecture

on-chip

Atmel SAM0 multi-protocol (UART, SPI, I2C) SERCOM unit3

atmel,sam0-sercom

on-chip

For locating the Device ID (serial number) on Atmel SAM0 devices1

atmel,sam0-id

Clock control

on-chip

Atmel SAM0 Main Clock Controller (MCLK)1

atmel,sam0-mclk

on-chip

Atmel SAMD0 Generic Clock Controller (GCLK)1

atmel,sam0-gclk

Counter

on-chip

Atmel SAM0 basic timer counter (TC) operating in 32-bit wide mode2

atmel,sam0-tc32

DAC

on-chip

Atmel SAM0 family DAC1

atmel,sam0-dac

DMA

on-chip

Atmel SAM0 DMA controller1

atmel,sam0-dmac

Flash controller

on-chip

Atmel SAM0 NVMC (Non-Volatile Memory Controller)1

atmel,sam0-nvmctrl

GPIO & Headers

on-chip

SAM0 GPIO PORT node2

atmel,sam0-gpio

Interrupt controller

on-chip

ARMv6-M NVIC (Nested Vectored Interrupt Controller) controller1

arm,v6m-nvic

on-chip

Atmel SAM0 series External Interrupt Controller1

atmel,sam0-eic

LED

on-board

Group of GPIO-controlled LEDs1

gpio-leds

on-board

Group of PWM-controlled LEDs1

pwm-leds

MTD

on-chip

Flash node1

soc-nv-flash

on-board

Fixed partitions of a flash (or other non-volatile storage) memory1

fixed-partitions

Pin control

on-chip

Atmel SAM0 PINMUX2

atmel,sam0-pinmux

on-chip

Atmel SAM0 Pinctrl Container1

atmel,sam0-pinctrl

PWM

on-chip

Atmel SAM0 TCC in PWM mode1

atmel,sam0-tcc-pwm

RTC

on-chip

Atmel SAM0 RTC1

atmel,sam0-rtc

Serial controller

on-chip

Atmel SAM0 SERCOM UART driver2

atmel,sam0-uart

SPI

on-chip

Atmel SAM0 SERCOM SPI controller1

atmel,sam0-spi

SRAM

on-chip

Generic on-chip SRAM description1

mmio-sram

Timer

on-chip

ARMv6-M System Tick1

arm,armv6m-systick

USB

on-chip

Atmel SAM0 USB in device mode1

atmel,sam0-usb

Watchdog

on-chip

Atmel SAM0 watchdog1

atmel,sam0-watchdog

Connections and IOs

The Arduino store [1] has detailed information about board connections. Download the Arduino Zero Schematic [2] for more detail.

System Clock

The SAMD21 MCU is configured to use the 32.768 kHz external oscillator with the on-chip PLL generating the 48 MHz system clock. The internal APB and GCLK unit are set up in the same way as the upstream Arduino libraries.

Serial Port

The SAMD21 MCU has 6 SERCOM based USARTs. One of the USARTs (SERCOM5) is connected to the onboard Atmel Embedded Debugger (EDBG). SERCOM0 is available on the D0/D1 pins.

PWM

The SAMD21 MCU has 3 TCC based PWM units with up to 4 outputs each and a period of 24 bits or 16 bits. If CONFIG_PWM_SAM0_TCC is enabled then LED0 is driven by TCC2 instead of by GPIO.

SPI Port

The SAMD21 MCU has 6 SERCOM based SPIs. On the Arduino Zero, SERCOM4 is available on the 6 pin connector at the edge of the board.

USB Device Port

The SAMD21 MCU has a USB device port that can be used to communicate with a host PC. See the USB device support sample applications for more, such as the USB CDC-ACM sample which sets up a virtual serial port that echos characters back to the host PC.

DAC

The SAMD21 MCU has a single channel DAC with 10 bits of resolution. On the Arduino Zero, the DAC is available on pin A0.

Programming and Debugging

The Arduino Zero comes with a Atmel Embedded Debugger (EDBG). This provides a debug interface to the SAMD21 chip and is supported by OpenOCD.

Flashing

  1. Build the Zephyr kernel and the Hello World sample application:

    west build -b arduino_zero samples/hello_world
    
  2. Connect the Arduino Zero to your host computer using the USB debug port.

  3. Run your favorite terminal program to listen for output. Under Linux the terminal should be /dev/ttyACM0. For example:

    $ minicom -D /dev/ttyACM0 -o
    

    The -o option tells minicom not to send the modem initialization string. Connection should be configured as follows:

    • Speed: 115200

    • Data: 8 bits

    • Parity: None

    • Stop bits: 1

  4. To flash an image:

    west build -b arduino_zero samples/hello_world
    west flash
    

    You should see “Hello World! arduino_zero” in your terminal.

References