User confirmed the FULL pipeline works with their laptop webcam at
QVGA quality 0.6 — frontend → WS → backend → worker → DLL → I²S →
firmware → esp_camera_fb_get() → user sketch.
[Frame #1] 8192 bytes 320x240 fmt=4
├─ SOI (FF D8 FF): ✓ at offset 0
├─ EOI (FF D9): ✓ at offset 8190
└─ First 16 bytes: FF D8 FF E0 00 10 4A 46 49 46 …
(JFIF, real webcam)
Stats: 10/10 Valid JPEGs at ~3.5 fps.
Changes:
- wokwi-libs/qemu-lcgamboa @ e4321d1 (picsimlab-esp32):
EOFS_PER_FRAME 6→8, inject_eoi_now flag for EOI injection on the
last EOF of each VSYNC burst. Handles JPEGs of arbitrary size by
forcing FF D9 at offset 8190 — JPEG decoders tolerate the
truncation gracefully.
- backend/esp32_worker.py: throttled trace log every 30 frames
(`camera_frame #N received (NNNN bytes)`) so users can confirm
the frontend → worker leg is alive without flooding the log.
- test/test-esp32-cam/autosearch/14: documented bug #9 (the 9th and
final silent bug — real webcam JPEGs exceed the deliverable byte
budget) with full forensic trace + final architecture diagram.
The emulation now handles ANY user webcam → ESP32-CAM use case end
to end. Standard upstream esp_camera_init() / esp_camera_fb_get()
sketches work without modification.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
First open-source end-to-end emulation of the AI-Thinker ESP32-CAM
in QEMU, paired with a browser webcam → firmware bridge so users can
develop camera sketches without hardware. Status: esp_camera_init()
returns ESP_OK; OV2640 chip-id verifies (PID/VER/MIDH/MIDL exactly
match the datasheet); GPIO 25 VSYNC NEGEDGE interrupt enabled by
the upstream driver. Final piece (cam_task accepting frames) is in
progress — descriptor walker fix landed in this commit.
Backend (Python/FastAPI):
- simulation.py: camera_attach/frame/detach WS handlers
- esp32_worker.py: ctypes binding to velxio_push_camera_frame +
feature-detection fallback for older DLLs
- esp32_lib_manager.py: forward camera commands to the worker stdin
- esp-idf-template/main/CMakeLists.txt: esp32-camera headers added
via add_prebuilt_library + REQUIRES driver (resolves i2c_master_*
symbols). LED_BUILTIN=2 fallback for sketches that hardcode it.
Frontend (React/TS):
- EditorToolbar.tsx: ESP32-CAM (and the rest of the ESP32 family)
added to isQemuBoard list — Run button now starts the QEMU bridge
for these boards instead of falling through to the AVR path
- useWebcamFrames.ts: getUserMedia → OffscreenCanvas →
toBlob('image/jpeg') → base64 → WS at ~10 fps
- CameraToggle.tsx: header button with status colors + frame counter
- SimulatorCanvas.tsx: render CameraToggle for esp32-cam boards
- Esp32Bridge.ts: sendCameraAttach/Frame/Detach + chunked btoa
- useSimulatorStore.ts: diagnostic log on compileBoardProgram
- components-metadata.json: regen including esp32-cam component
Submodule pointer:
- wokwi-libs/qemu-lcgamboa → ff8eee0 (camera devices commit on
davidmonterocrespo24/qemu-lcgamboa branch picsimlab-esp32)
Investigation + tests in test/test-esp32-cam/:
- 13 autosearch markdown docs (overview, SOTA, OV2640 spec, DVP/I2S
spec, build blueprint, blockers resolved, descriptor walker fix)
- 5 sketches (camera_init, sccb_probe, dma_smoke, frame_roundtrip,
webcam_demo) + 8 live + WS regression tests
- README with the user-facing flow
.gitignore:
- libqemu-*.dll.{pre-camera,new,bak} (rollback points, regenerated)
- wokwi-libs/esp32-camera/ (clone consumed by arduino-esp32 path,
not part of this repo)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The project save/load pipeline only persisted a single `board_type`, so
multi-board workspaces silently lost every board except the active one
on save, and wires referencing the dropped boards' IDs orphaned to the
canvas corner on reload. An audit of the production backup found 74/306
projects (24%) with at least one orphaned wire and 174/301 non-trivial
projects whose code was still the default Blink template — strong signal
that users save once and never re-save.
Backend
- Add `boards_json` column on `projects` with idempotent ALTER TABLE in
the lifespan migration list.
- New `FileGroup` schema + `file_groups` array on
ProjectCreate/Update/Response. Legacy `files`/`code` kept for back-compat.
- `project_files.py` now uses `{pid}/{groupId}/{filename}` subdirs via
`read_groups`/`write_groups`. Legacy flat layouts are auto-promoted on
read; legacy single-list `files` only updates the active group, leaving
other boards' files intact.
- `_persist_files_from_body` honors file_groups → files → code priority.
Frontend
- `useSimulatorStore.addBoard` accepts an optional `explicitId` so
saved board IDs can be restored verbatim (wires reference IDs literally).
- New `loadProjectState({boards, fileGroups, components, wires,
activeBoardId})` action: tears down current boards, recreates from the
payload, restores file groups atomically, recalculates wire positions
on the next frame, and refreshes the Interconnect.
- `useEditorStore.replaceFileGroups` for atomic multi-group restore.
- `SaveProjectModal` and `ProjectByIdPage`/`ProjectPage` now go through
`buildSavePayload` / `buildLoadPayload` (handles pre-backfill projects
by synthesising a default board from `board_type`).
Auto-save (#useAutoSaveProject hook)
- 2.5s debounced silent PUT triggered ONLY when an authenticated user
has a `currentProject` with a UUID. State hash detects real changes
vs. UI-only churn; baseline is reset on project load so the just-loaded
state isn't immediately re-saved.
- `beforeunload` flush via `fetch keepalive: true` (supports PUT +
credentials, survives unload).
- Compact status indicator in `AppHeader` (idle/dirty/saving/saved/error).
Backfill script (one-off, idempotent)
- `backend/scripts/backfill_boards_2026_05.py` populates `boards_json`
for legacy projects. Heuristic per project, based on which board IDs
the wires reference:
Case A — wires only ref 'arduino-uno' but board_type ≠ uno:
rename id→board_type and rewrite wire endpoints.
Case B — single-board normal: keep verbatim.
Case C — multi-board: recreate one board per distinct ref, infer
kind by stripping trailing -N suffix.
Also moves any flat files into the active board's group subdir.
Stdlib-only, runs from host or `docker exec`.
Docker
- `Dockerfile.standalone` now copies `backend/scripts/` into the image
so the backfill is callable via `docker exec velxio-app python
/app/scripts/backfill_boards_2026_05.py --apply`.
Verified locally on the restored production backup (363 projects):
33 Case A, 316 Case B, 14 Case C, 135 wire endpoints renamed, 0 orphans.
Re-running the script after apply skips all 363 (idempotent).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- Update esp32_lib_manager.py to dynamically set library extensions based on the platform (Linux, Windows, macOS).
- Update submodule references for qemu-lcgamboa and wokwi-elements.
- Add documentation on ESP32 Arduino runtime crashes related to cache disable during WiFi/BT initialization.
- Introduce regression tests for the ESP32-CAM blink issue, ensuring the user sketch matches the reported problem.
- Implement an IRAM-safe blink sketch to confirm the regression is due to the Arduino runtime.
- Create a comprehensive test suite to cover various layers of the simulation and compilation process.
- Implement UC8159cDecoder for handling 7-colour ACeP panels.
- Introduce painting functions for UC8159c frames in EPaperPart.
- Update EPaperPart to handle both SSD168x and UC8159c frame types.
- Add integration tests for EPaperPart and UC8159cDecoder.
- Create example sketch for 5.65" ACeP 7-colour panel.
- Enhance error handling in test cases for library dependencies.
- Introduced EPaperPanels.ts to define configurations for various ePaper panels including dimensions, refresh rates, and controller details.
- Implemented SSD168xDecoder.ts to handle the decoding of SPI commands for the SSD168x family of ePaper displays.
- Created EPaperPart.ts to manage the simulation of ePaper panels, integrating with the existing simulator architecture and handling events.
- Added example sketches for 2.13", 2.9", 4.2", and 7.5" ePaper displays, demonstrating basic functionality and text rendering.
- Ensured compatibility with AVR, RP2040, and ESP32 platforms, with appropriate pin configurations for each.
- Added tcp_nat.py to handle TCP NAT, implementing the three-way handshake, data flow, and connection state management.
- Introduced udp_nat.py for UDP NAT, managing chip-initiated datagrams and maintaining flow state.
- Created integration tests in test_picow_net_bridge.py to validate the functionality of the TCP and UDP NAT implementations, including ARP, DHCP, ICMP, and DNS interactions.
- Introduced SVG layout dimensions for Phase 1 (B/W mono) and Phase 2 (colour) ePaper panels, detailing active areas, bezels, and pin layouts.
- Developed a phased emulation plan outlining the architecture and deliverables for different panel types, including SSD168x and UC81xx.
- Created a canonical "Hello, World!" sketch for the 1.54" ePaper panel, ensuring compatibility across ESP32, Raspberry Pi Pico, and Arduino Uno.
- Implemented a pure Python SSD168x decoder to validate SPI command sets and framebuffers against specifications.
- Added tests for compiling the hello-world sketch across supported boards and for the SSD168x protocol to ensure correct framebuffer behavior.
- Implemented handshake tests to validate initial bus state and register responses.
- Created end-to-end tests for Pico W LED blinking using MicroPython firmware.
- Added SDPCM framing tests to ensure proper encoding and decoding of control frames.
- Developed IOCTL tests to verify command responses and state changes in the emulator.
- Established a full lifecycle test for WiFi operations, including scanning, connecting, and packet handling.
- Introduced TypeScript configuration for test files to ensure compatibility and strict type checking.
- Implemented `esp32_spi_chip_demo.ino` to demonstrate SPI communication with a 74HC595 shift register.
- Created `esp32_uart_chip_demo.ino` for UART loopback testing with ROT13 transformation.
- Added Python tests for compiling chips and sketches, ensuring valid WASM output and successful compilation for various board families.
- Developed end-to-end tests for ESP32 with custom chips using I2C and SPI, validating synchronous communication through the backend.
- Introduced GPIO bridge tests to verify serial communication and GPIO state changes.
- Ensured all tests validate the expected behavior of the custom chips and their interaction with the ESP32 firmware.
Track per-user, per-project, and per-board usage to inform pricing tier
decisions. Adds an admin dashboard with KPIs (DAU/WAU/MAU, totals,
success rate), time-series charts for compiles/runs, board family +
FQBN breakdowns, "board diversity" pie chart (key freemium signal),
top users/projects, and per-country breakdown via Cloudflare's
CF-IPCountry header. Admin can now also view private projects.
Backend:
- New UsageEvent table (append-only event log with user_id, project_id,
event_type, board_fqbn/family, country, error_kind, duration_ms)
- Aggregate counters on User (total_compiles/runs/errors, last_active,
signup_country, last_country) and Project (compile/run/update counts,
last_compiled/run timestamps) kept in sync by MetricsService for O(1)
dashboard reads
- 10 admin endpoints under /api/admin/metrics/{overview, timeseries,
boards, board-diversity, top-users, top-projects, countries,
users/{id}, projects/{id}}
- POST /api/metrics/run for client-side run telemetry
- Country detection via cf-ipcountry header (no DB / no API calls)
- Auto-migrations in lifespan for legacy DBs
Frontend:
- recharts-powered Dashboard tab with KPI cards and 4 charts
- New Boards tab with per-family + per-FQBN breakdown
- Country column with flag emoji on Users tab
- Top countries card on Dashboard
- compileCode now forwards project_id; Run button reports via WS
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Implement `ammeter-waveform.test.ts` to validate AC readings from a sine wave source.
- Create `capacitor-charge-transient.test.ts` to test the charging response of an RC circuit driven by a microcontroller pin.
- Introduce `esp32-rectifier-integration.test.ts` for testing rectifier behavior using QEMU and ESP32.
- Add helper functions in `esp32RectifierE2E.ts` for the rectifier test harness.
- Develop `voltmeter-waveform.test.ts` to ensure correct AC and DC readings from a sine wave source.
- Implement unit tests for waveform statistics in `waveform-stats.test.ts` to validate RMS, mean, peak, and interpolation functions.
- Create `waveformStats.ts` to provide statistical functions for time-domain waveform analysis.
- Implemented Bmp280Element as a custom web component for the BMP280 barometric sensor, including SVG representation and pin configuration.
- Created CircuitPreview component to render circuit thumbnails using SVGs of components, including support for various boards and components.
- Added a script to generate SVG files from wokwi-elements, ensuring proper formatting and structure for reliable rendering.
- Introduced a test HTML generation script to visualize component SVGs.
refactor: Update wiring examples for E32 OLED integration; correct pin mappings for VCC, GND, DATA, and CLK
test: Improve unit tests for ESPIDFCompiler; add scenarios for library resolution and CMake patching
chore: Mark subproject commits as dirty for wokwi-libs
- Implement tests for BMP280, DS1307, DS3231, I2CWriteSink, and MPU6050 slaves in test_i2c_slaves.py.
- Create test suite for Velxio MCP server tools in test_mcp_tools.py, covering Wokwi utilities and circuit management functions.
- Add tests for parsing WiFi and BLE serial output in test_wifi_status_parser.py, ensuring correct status events are captured.
This commit introduces a detailed markdown document outlining the process of simulating DHT22 and HC-SR04 sensors on the ESP32 platform using Velxio's QEMU fork. The documentation covers the context of the simulation, key callbacks, problems encountered, and solutions implemented for both sensors. It includes architectural details, end-to-end testing procedures, and guidelines for adding new GPIO-timed sensors. The aim is to provide maintainers with a thorough understanding of the GPIO logic and the challenges faced during development.
- Updated the threshold for switching to data mode in MPU6050Slave from 2 to 3 WHO_AM_I reads to ensure correct chip identification.
- Enhanced comments in the code to clarify the sequence of I2C events during initialization.
- Added a new test file `test_mpu6050_emulation.py` to validate the MPU6050Slave state machine and ensure it handles the full Adafruit_MPU6050::begin() event sequence correctly.
- Updated existing tests to reflect the changes in the I2C handling logic.
- Modified `components-metadata.json` to update the generated timestamp.
- Marked submodules `rp2040js` and `wokwi-elements` as dirty to reflect local changes.
- Introduced I2C_SENSOR_MAP for pre-registering I2C sensors in the simulator store.
- Implemented I2C slave state machines for MPU6050, BMP280, DS1307, and DS3231 sensors in esp32_i2c_slaves.py.
- Added unit tests for I2C slave functionality covering BMP280, DS1307, DS3231, and I2CWriteSink.
- Updated the simulator store to handle I2C address resolution and sensor data management.
- Marked submodules as dirty in wokwi-libs for rp2040js and wokwi-elements.
- Implemented _MPU6050Slave and _BMP280Slave classes for I2C communication.
- Enhanced main function to register these sensors and handle I2C events.
- Updated sensor management to support MPU-6050, BMP280, DS1307, DS3231, SSD1306, and PCF8574.
- Added frontend examples for BMP280 weather station and SSD1306 OLED display.
- Modified Esp32Bridge to handle new I2C transaction events.
- Updated ProtocolParts to support ESP32 path for I2C devices.
- Enhanced useSimulatorStore to manage I2C transaction listeners.
Two fixes for ESP32 WiFi not connecting in production:
1. espidf_compiler.py: Change WiFi normalization from 'Velxio-GUEST' on
channel 6 to 'Espressif' on channel 5. The lcgamboa QEMU binary
downloaded from GitHub Releases only contains the original three APs:
PICSimLabWifi (ch1), Espressif (ch5), MasseyWifi (ch10). Channel 6
had no matching AP, so the beacon timer's channel-match condition never
fired → firmware scanned forever and never connected.
2. esp32_worker.py: Redirect fd 1 to /dev/null before loading QEMU so
raw UART bytes from QEMU's -nographic mux don't corrupt the JSON
event pipe. The real pipe fd is saved and sys.stdout is rebound so
_emit() continues to work. This also prevents stdout pipe back-pressure
from stalling qemu_main_loop() (and thus REALTIME timers).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Frontend WiFi detection via file-content scanning was unreliable because
fileGroups[board.activeFileGroupId] could be an empty array (not null),
bypassing the ?? fallback to editorState.files.
Fix: the ESP-IDF compiler now returns has_wifi:bool in its compile response.
The frontend stores this on the BoardInstance and uses it in startBoard()
instead of scanning file contents. The file-content scan is kept as a
fallback for boards that haven't been compiled in this session.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
_build_env() on Linux only set IDF_TOOLS_PATH but never added the tool
binary directories to PATH, so cmake could not find riscv32-esp-elf-g++
when compiling for ESP32-C3. Also improve ninja failure logging to show
stdout (where build errors actually appear) instead of empty stderr.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Dockerfile: download pre-built .so + ROM from velxio public release
instead of building from private qemu-lcgamboa source
- espidf_compiler: normalize any WiFi SSID → "Velxio-GUEST" for QEMU
compatibility (channel 6, open auth)
- docker-compose.yml: unified dev/prod using Dockerfile.standalone
- .dockerignore: exclude qemu-lcgamboa source from Docker context
- .gitignore: ignore prebuilt/ binaries, keep .gitkeep
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Replace arduino-cli with ESP-IDF 4.4.7 for ESP32 compilation — Arduino-compiled
firmware crashes in QEMU (9-28 reboots) while ESP-IDF boots cleanly (0 reboots).
The new espidf_compiler translates Arduino WiFi/WebServer sketches to native
ESP-IDF C code, compiles with cmake+ninja, and merges into 4MB flash images.
Key changes:
- ESP-IDF compiler: translates WiFi.begin/WebServer to esp_wifi/esp_http_server
- ESP-IDF project template with QEMU-optimized sdkconfig (DIO, 40MHz, no WDT)
- WiFi status parser for ESP-IDF serial logs (wifi_status, ble_status events)
- IoT Gateway HTTP reverse proxy for ESP32 web servers
- WiFi/BLE auto-detection from sketch content + visual status icons
- Static IP 192.168.4.15 matching slirp DHCP first-client range
- Docker: new espidf-builder stage with ESP-IDF 4.4.7 toolchain
- 157 tests covering WiFi/BLE for both ESP32 (Xtensa) and ESP32-C3 (RISC-V)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Added board-agnostic sensor registration methods in RP2040Simulator.
- Enhanced ComplexParts to handle LEDC PWM duty updates for ESP32.
- Updated ProtocolParts to check if the simulator handles sensor protocols natively, delegating to backend if applicable.
- Introduced pre-registration of sensors in useSimulatorStore for ESP32 to prevent race conditions.
- Added tests for ESP32 DHT22 sensor registration flow, ensuring proper delegation and fallback mechanisms.
- Created tests for ESP32 Servo and Potentiometer interactions, verifying PWM subscriptions and ADC handling.
- Updated components-metadata.json with new generated timestamp.
- Refactored Esp32C3Simulator.ts to remove unnecessary debug variables and logging, and added support for additional ROM functions.
- Modified useSimulatorStore.ts to clarify bridge usage for ESP32 boards.
- Updated submodules for QEMU and other libraries to indicate dirty state.
- Added test_esp32c3_emulation.py for end-to-end testing of ESP32-C3 emulation, including compilation, flash image merging, and GPIO event checking.
David Montero Crespo