Brings hardware flashing into Velxio Desktop. Per-board "Flash to
real board" entry in the canvas context menu opens a modal that
enumerates USB serial ports, lets the user pick one, then
streams arduino-cli upload output live until the board is flashed.
Backend (Phase D1) — backend/app/api/routes/flash.py (new):
POST /api/flash/upload (multipart: board_id, port, fqbn,
program_format, program)
→ SSE stream of {phase, line?, progress?} events
→ final {phase:'done', success, elapsed_ms, error?}
- Wraps `arduino-cli upload -p <port> -i <file> --fqbn <fqbn> -v`
so AVR (avrdude), ESP32 (esptool), RP2040 (picotool), SAMD
(bossac) all share one code path — arduino-cli internally
dispatches by FQBN.
- Per-port asyncio.Lock prevents two simultaneous flashes from
fighting over the same /dev/ttyACM0.
- Allow-list of FQBN prefixes (arduino:avr, ATTinyCore:avr,
rp2040:rp2040, esp32:esp32, arduino:samd) so a typo can't
cause a confusing arduino-cli error.
- Format allow-list (hex / bin / uf2 / elf) drives the temp
file extension - arduino-cli uses the extension to route to
the right uploader.
- 8MB hard cap on the uploaded program (real sketches are
well under that; protects against a runaway frontend).
- X-Accel-Buffering: no header so nginx doesn't hold the SSE
chunks until the flash completes.
Frontend (Phase D3):
- frontend/src/services/flashService.ts (new):
async generator streamFlash() yields parsed SSE events.
Handles the base64-vs-text gotcha (compile returns hex_content
as text but binary_content as base64; for binary formats we
atob() into a Uint8Array before posting so the form upload
sends actual bytes, not the base64 ASCII).
- frontend/src/components/simulator/FlashModal.tsx (new):
Three-state UI: picking (port dropdown), flashing (progress
bar + live log), success/error (verdict + retry).
Empty-ports state shows a Linux dialout-group hint.
- SimulatorCanvas.tsx: board context menu gains "Flash to real
board" entry, gated on isTauri() + presence of compiledProgram.
Hidden in web (WebSerial is a separate sprint).
- tauriBridge.ts: SerialPortInfo type + listSerialPorts() helper
that invokes the Rust shell command added in Phase D2.
The sidecar already has arduino-cli on PATH (per
`pro/desktop/sidecar/main.py::_expose_bundled_arduino_cli`), so
no installer changes are needed — flash works the moment the
0.4.x desktop bundle ships with these commits.
Plan + remaining phase tracked in project/hardware-flashing/.
D2 (Rust serial enum) committed separately as a Tauri-shell-only
concern; D4 (manual smoke matrix with real boards) requires
physical hardware so it stays a follow-up.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>