Arduino Nano Nora Recovery Sketch

This sketch implements the DFU recovery mode logic, called by all sketches when a double tap on the RESET button is detected. It should not be uploaded as any other sketch; instead, this should be compiled and then flashed in the module's factory partition.

Compilation

The binary can be compiled with the Arduino 2.x IDE or CLI using the nano_nora variant. In particular, using the CLI the resulting binary can be exported to the build directory with the -e switch to arduino-cli compile.

Automatic installation

By replacing the binary in the current folder, automatic installation can be performed by running the "Upload with Programmer" action on any sketch in the Arduino 2.x IDE or CLI. In particular, using the CLI the binary can be installed via the command:

arduino-cli compile -u --programmer esptool

Manual installation

Once compiled, the binary can also be installed on a board using esptool.py with the following command:

esptool.py --chip esp32s3 --port "/dev/ttyACM0" --baud 921600  --before default_reset --after hard_reset write_flash  -z --flash_mode dio --flash_freq 80m --flash_size 16MB 0xF70000 "nora_recovery.ino.bin"

where:

• esptool.py is located in your core's install path under tools/esptool_py;
• /dev/ttyACM0 is the serial port exposed by the board to be used;
• 0xF70000 is the factory partition address (make sure it matches the offset in the variant's {build.partitions} file);
• nora_recovery.ino.bin is the compiled sketch image.

Due to a BSP issue, the first call to esptool.py will enter the hardware bootloader for programming, but fail with an "Input/output error". This is a known issue; calling the program again with the same arguments will now work correctly.

Once flashing is complete, a power cycle (or RESET button tap) is required to leave the esptool.py flashing mode and load user sketches.