14.1.1.3.5.4. Arduino boards¶

The STM32-based Arduino boards (Portenta H7, Giga, Nicla Vision) are flashed with dfu-util using absolute flash addresses through the Arduino DFU bootloader. The two Nano boards use their own tools.

14.1.1.3.5.4.1. STM32 Arduino boards: dfu-util¶

To enter the bootloader, double-tap the reset button (or open the board’s serial port at 1200 baud – the Arduino “touch” reset).

Board	DFU VID:PID	Firmware command	ROMFS command
Arduino Portenta H7	`2341:035b`	`-a 0 -s 0x08040000`	`-a 1 -s 0x90B00000:leave`
Arduino Giga	`2341:0366`	`-a 0 -s 0x08040000`	`-a 1 -s 0x90B00000:leave`
Arduino Nicla Vision	`2341:035f`	`-a 0 -s 0x08040000`	`-a 1 -s 0x90B00000:leave`

Flash the application (Nicla Vision shown):

dfu-util -w -d ,2341:035f -a 0 -s 0x08040000 -D firmware.bin

Wi-Fi and Bluetooth need two additional blobs shipped with OpenMV IDE in share/qtcreator/firmware/CYW4343/:

Component	Flash address	File
Wi-Fi firmware	`0x90F00000`	`cyw4343_7_45_98_102.bin`
Bluetooth firmware	`0x90FC0000`	`cyw4343_btfw.bin`

Flash both onto the external flash alt, with :leave on the final transfer (Nicla Vision shown):

dfu-util -w -d ,2341:035f -a 1 -s 0x90F00000 -D cyw4343_7_45_98_102.bin
dfu-util -w -d ,2341:035f -a 1 -s 0x90FC0000:leave -D cyw4343_btfw.bin

14.1.1.3.5.4.2. Arduino Nano 33 BLE Sense: bossac¶

The Nano 33 BLE Sense (nRF52840) does not use dfu-util. To enter the bootloader, double-tap the RESET button; the board enumerates as the nRF52840 DFU device (2341:805a). Flash it with bossac, writing the application at flash offset 0x16000 – above the factory SoftDevice and bootloader, which are never written:

bossac -e -w -v -R --offset=0x16000 firmware.bin

14.1.1.3.5.4.3. Arduino Nano RP2040 Connect: picotool¶

To enter the bootloader, hold the BOOTSEL button while connecting USB; the board mounts a USB mass-storage drive named RPI-RP2. Flash it either by copying a .uf2 file onto that drive, or with picotool:

picotool load -x firmware.uf2

Warning

The Arduino boards’ bootloaders are factory-locked and cannot be restored by the user – only the application region is ever written. A damaged Arduino bootloader must be recovered with Arduino’s own tooling. The bootloader-restore procedures in Restoring the bootloader apply to the OpenMV-branded cameras only.