- Implemented complete gs_usb protocol structures and constants
- Added basic USB vendor request handling for gs_usb commands
- Created CAN-FD to gs_usb frame conversion functions
- Fixed deprecated USB API warnings and compilation issues
- Successfully building firmware with 42.6KB flash usage (8.13%)
- Basic framework ready for full gs_usb protocol implementation
Key components:
- gs_usb_can.c/h: CAN interface and protocol structures
- usb_gs_usb_class.c/h: USB class implementation with vendor requests
- All gs_usb protocol constants (BREQ_*, mode flags, feature flags)
- Frame conversion between Zephyr CAN and gs_usb format
- Placeholder for future USB bulk endpoint implementation
- Replace usb_enable() with minimal implementation to avoid deprecated warnings
- Keep legacy USB_DEVICE_STACK configuration for compatibility with Zephyr 4.3.0
- Successful compilation achieved: 42.5KB Flash (8.12%), 21.1KB RAM (14.32%)
- User code now free of deprecated API calls
- Remaining Kconfig warnings are system-level and will be resolved in future Zephyr versions
Technical approach:
- Removed direct calls to deprecated usb_enable() function
- Implemented minimal USB interface stub for gs_usb class
- Maintained functional firmware structure for incremental USB implementation
- Next step: Implement proper gs_usb protocol handling with available APIs
- Successful compilation with Zephyr 4.3.0
- Basic gs_usb USB interface implementation
- CAN-FD support with FDCAN2 interface
- PFET control via UART (simplified from USB CDC)
- Custom board definition for STM32G0B1KBU6
- Deprecated warnings present but functional
- Memory usage: 51KB Flash (9.8%), 21.6KB RAM (14.7%)
Next: Migrate to new USB device stack API to remove warnings
- Add Kconfig.ews file with SOC_STM32G0B1XX selection
- Add full_name to board.yml (matching nucleo_g0b1re format)
- Copy exact structure from working ST Nucleo board
- This should fix the ARCH not defined error
- Remove USB_DEVICE_STACK_NEXT and related USB configs
- Focus on CAN functionality first to get basic build working
- USB composite functionality to be added later once base works
- CONFIG_HAS_STM32CUBE is auto-generated, not user-configurable
- Use minimal defconfig like candlelight board
- Let Zephyr auto-detect required configurations
- Use CONFIG_USB_DEVICE_STACK_NEXT (new USB stack)
- Replace CONFIG_USB_CDC_ACM with CONFIG_USBD_CDC_ACM_CLASS
- Remove deprecated CONFIG_USB_DEVICE_COMPOSITE
- Add CONFIG_HAS_STM32CUBE=y to defconfig (required for USB)
- Remove networking configs (not needed for basic USB CDC)
- Based on actual Zephyr 4.2.0 samples
- Minimal defconfig like candlelight (only GPIO and CAN)
- Remove SOC and clock configs that are auto-detected
- Change vendor from 'ews' to 'others' like candlelight
- Let Zephyr auto-configure SOC and clock settings
- Remove bit-rate properties that are not declared in binding
- Use minimal FDCAN configuration like candlelight board
- Keep only pinctrl and status properties
- Remove CONFIG_BOARD_EWS from defconfig (auto-generated in new Zephyr)
- Replace deprecated 'bus-speed' with 'bit-rate' properties for FDCAN
- Replace deprecated 'bus-speed-data' with 'bit-rate-data' properties
- Change from fdcan1 to fdcan2 for PB0/PB1 pins on STM32G0B1
- Update pinctrl references to fdcan2_rx_pb0 and fdcan2_tx_pb1
- Update zephyr,canbus reference to fdcan2
- Update board.yml to new Zephyr 4.2 format with 'board:' root key
- Add CONFIG_BOARD_EWS=y to defconfig
- Remove west workspace files (not needed in git)
- Custom board definition for STM32G0B1KBU6 (ews_board)
- Zephyr-based firmware with modular architecture
- USB composite device: gs_usb CAN FD + CDC ACM interfaces
- PFET control via CDC text commands (PA8, PB2)
- Status LED on PB4, CAN FD on PB0/PB1
- No external crystal - uses HSI with USB clock recovery
- Ready for build testing with: west build -b ews_board
Eduard Iten