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.
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
Build the Zephyr kernel and the Hello World sample application:
west build -b arduino_nano_33_iot samples/hello_world
Connect the Nano 33 IOT to your host computer using USB
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.
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
Tap the reset button twice quickly to enter bootloader mode
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.