UART/USB now receive in the background and store into ring buffers.
Callers read from the buffer via non-blocking ReadByte/ReadBuffer.
Removed blocking ReceiveByte, async ReceiveBuffer with request
state and callbacks. MCU_USB uses lazy drain from SDK stdio into
its own ring buffer. MCU_UART ring buffer unchanged (ISR/DMA).
HAL_COM updated with ReadByte/ReadBuffer function pointer dispatch.
APP_CLSW updated to use new ReadByte API.
MCU_UART: full RX with ISR and DMA modes, ring buffer, blocking
ReceiveByte, async ReceiveBuffer with request fulfillment, blocking
ReceiveBufferBlocking. Per-byte RX callback (ISR mode).
MCU_USB: blocking ReceiveByte via getchar_timeout_us, cached-byte
peek for bIsRxDataAvailable.
HAL_COM: RX function pointer types + dispatch (ReceiveByte,
bIsRxDataAvailable) with USB wrappers in cfg.
APP_CLSW: interactive command parser. Accumulates input into a
buffer, parses on delimiter. Supports red/green/blue/help commands
with echo and response. SYS_ECU tick reduced to 10ms for responsive
input.
Dockerized build system (Dockerfile, docker-compose, build.sh) with
Pico SDK cross-compilation. Modular CMake split into project_config,
mcu_config, and sources_config under cmake/. Component architecture
following inc/prg/cfg convention: STD_TYPES, MCU_USB, HAL_COM,
APP_CLSW, SYS_ECU. Full call chain SYS_ECU -> APP_CLSW -> HAL_COM
-> MCU_USB verified end-to-end on RP2040-Zero hardware over USB-CDC.
Includes flash.sh for automated .uf2 flashing on macOS and
devcontainer config for VS Code.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
