Tinymovr Firmware 2.5.1

Preserve NVM config during DFU firmware updates

This release fixes a critical issue where firmware updates via DFU would reset the CAN node ID to 1, causing conflicts on multi-device CAN buses.

Changes

• DFU NVM preservation: The DFU script now backs up and restores the NVM config region (pages 120-127) around the erase operation, preventing config loss during firmware updates
• Documentation: Added documentation about bootloader CAN ID behavior (reads from slot 0, not wear-leveled latest)

Technical Details

The bootloader's erase_all command wipes pages 4-127, including the NVM config region. The DFU script (tinymovr_dfu) now:

1. Reads the entire 8 KB NVM region before erasing
2. Performs the firmware flash
3. Writes the NVM data back before reset

This ensures the CAN node ID and all other settings survive firmware updates without the device ever appearing at default ID 1 on the bus.

Files Changed

• studio/Python/tinymovr/dfu.py: Added read_nvm_region() and write_nvm_region() functions
• ARCHITECTURE.md: Documented DFU NVM preservation and bootloader CAN ID behavior
• CLAUDE.md: Added gotcha about bootloader reading from slot 0