Arduino Nano 33 IOT

Overview

The Arduino Nano 33 IOT is a small form factor development board with USB, Wifi, Bluetooth, a 6 axis IMU, and secure element.

Arduino Nano 33 IOT

Hardware

  • ATSAMD21G18A ARM Cortex-M0+ processor at 48 MHz

  • 256 KiB flash memory and 32 KiB of RAM

  • One user LED

  • One reset button

  • Native USB port

  • Wifi and Bluetooth via a u-blox NINA-W102

  • ATECC608A secure element

  • LSM6DS3 six axis accelerometer and gyro

Supported Features

The arduino_nano_33_iot board configuration supports the following hardware features:

Interface

Controller

Driver/Component

ADC

on-chip

Analog to digital converter

COUNTER

on-chip

Pulse counter

DMA

on-chip

Direct memory access unit

Flash

on-chip

Can be used with LittleFS to store files

GPIO

on-chip

I/O ports

HWINFO

on-chip

Hardware info and serial number

NVIC

on-chip

nested vector interrupt controller

PWM

on-chip

Pulse Width Modulation

SPI

on-chip

Serial Peripheral Interface ports

SYSTICK

on-chip

systick

USART

on-chip

Serial ports

USB

on-chip

USB device

WDT

on-chip

Watchdog

Other hardware features are not currently supported by Zephyr.

The default configuration can be found in the Kconfig boards/arduino/nano_33_iot/arduino_nano_33_iot_defconfig.

Connections and IOs

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

System Clock

The SAMD21 MCU is configured to use the 8 MHz internal 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. SERCOM5 is available on pins 1 and 2.

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. SERCOM1 is available on pins 1, 14, and 15.

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.

Programming and Debugging

The Nano 33 IOT ships the BOSSA compatible UF2 bootloader. The bootloader can be entered by quickly tapping the reset button twice.

Additionally, if CONFIG_USB_CDC_ACM is enabled then the bootloader will be entered automatically when you run west flash.

Flashing

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

    west build -b arduino_nano_33_iot samples/hello_world

  2. Connect the Nano 33 IOT to your host computer using USB

  3. Connect a 3.3 V USB to serial adapter to the board and to the host. See the Serial Port section above for the board’s pin connections.

  4. 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

  5. Tap the reset button twice quickly to enter bootloader mode

  6. Flash the image:

    west build -b arduino_nano_33_iot samples/hello_world
west flash

    You should see “Hello World! arduino_nano_33_iot” in your terminal.

References