A board example proving digital and analog coexist in ONE circuit: the Arduino
drives two logic levels, a physical AND gate combines them, and the AND output
switches an NPN 2N2222 transistor that drives the "motor" LED. Verified live: it
compiles, the MCU drives the AND gate (5 V), the transistor conducts and the LED
lights — MCU -> logic gate -> transistor -> load works across the digital and
ngspice motors together.
Known limitation (sim-mixedmode step 2, pending): the ngspice side does not
re-solve on every MCU pin edge, so a fast (1 Hz) blink does not track in real
time — the analog output changes on a slower cadence. User-driven / slow changes
track fine. Snapshot updated for the new example.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The AND Gate Alarm needed BOTH inputs HIGH at once, but it used momentary
pushbuttons buffered through an Arduino — with one mouse you can only hold one
button at a time, so the AND never fired and the alarm could never be
demonstrated.
Rebuilt it as a board-less digital circuit: two SLIDE switches (they latch) feed
a real AND gate that drives the alarm LED. Slide both switches ON and they stay,
so the alarm arms. No MCU / compilation — it runs on the digital gate engine.
Verified live: the LED lights only on 11 (00/01/10 -> off, 11 -> on).
Snapshot updated: the new board-less and-gate-alarm netlist, plus the digital
bucket count label (38 -> 39) from the earlier ripple-counter example.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Five examples wired LEDs directly between a GPIO pin and GND with
no current-limiting resistor:
- examples.ts: traffic-light (3 LEDs), button-led (1), fade-led (1),
simon-says (4)
- examples-circuits.ts: mega-multi-led (8 LEDs)
In real hardware these wire-ups blow the LED in seconds. In the
simulator, ngspice cannot converge on a forward-biased diode with
no series resistance so the branch current comes back as NaN; the
LED visual stays dark even though the user's code is driving the
pin HIGH every cycle.
Adds a 220Ω wokwi-resistor per LED (textbook value for 5 V supplies
and standard diodes) and rewires:
arduino pin → r.1 / r.2 → led anode / led cathode → GND
The same upstream commit hardens the verifier (worst-case GPIO drive
in pre-flight) and the LED renderer (NaN guard) so this class of
mistake is now caught immediately and degrades gracefully when a
user creates their own broken circuit.
- Modified the index file to reflect the new naming convention for Velxio components.
- Changed JSX declarations to use 'velxio-' prefix for various components.
- Updated component overrides to replace 'wokwi-' with 'velxio-' for logic gates and other components.
- Adjusted SVG generation script to use 'velxio-' prefix for BMP280 and Raspberry Pi components.
- Marked submodules as dirty in QEMU and RP2040 libraries.
- Added .prettierignore and .prettierrc.json for consistent code formatting.
- Introduced InstrumentComponent with support for Voltmeter and Ammeter, including pin information handling.
- Replaced syncStoreProperty function with emitPropertyChange to decouple parts from Zustand store.
- Updated relay component mapping to ensure proper handling of coil and contact states.
- Added new test cases for half-wave rectifier and relay-controlled LED to ensure correct functionality.
- Introduced InlineComponentSVGs for schematic-style icons of various components.
- Updated submodule references for qemu-lcgamboa, rp2040js, and wokwi-elements to indicate dirty state.
- 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.
- Decoupled electrical simulation from the simulator store, ensuring SPICE is always active for accurate circuit analysis.
- Removed feature flag for electrical simulation, simplifying the state management.
- Preloaded SPICE engine at app start to eliminate latency during the first solve.
- Added comprehensive tests for MOSFET PWM LED behavior and NPN transistor switch functionality, ensuring correct current flow and response to pin states.
- Implemented diagnostics for floating input nodes in RC low-pass filter circuits, addressing singular matrix issues in SPICE simulations.
- Introduced active semiconductor metadata registry for better component management and simulation fidelity.
- Updated Vite configuration to force re-bundling of local wokwi-elements after component additions.
fix: increase timeout for compilation requests to 180 seconds
refactor: call recalculateAllWirePositions after loading examples
chore: update subproject commit for rp2040js to dirty state
chore: update subproject commit for wokwi-elements to dirty state
Adds frontend/src/data/examples-circuits.ts with 40 new examples organized
into 6 categories, each demonstrating a specific analog/digital/electromech
concept that the SPICE engine can simulate end-to-end:
PASSIVE / ANALOG (10):
voltage-divider, rc-low-pass-filter, wheatstone-bridge,
ntc-temperature, led-current-limiting, parallel-resistors,
pot-adc-reader, photoresistor-light, multi-led-bar,
capacitor-charge-curve
TRANSISTOR / SEMICONDUCTOR (8):
npn-led-switch, pnp-high-side-switch, mosfet-pwm-led,
diode-rectifier, zener-regulator, schottky-reverse-protection,
bjt-common-emitter, darlington-high-current
OP-AMP (5):
opamp-inverting, opamp-voltage-follower, opamp-comparator,
opamp-difference, opamp-schmitt-trigger
LOGIC GATES (6):
and-gate-alarm, xor-toggle-detector, nand-sr-latch,
full-adder, binary-counter-leds, logic-probe
ELECTROMECHANICAL (4):
relay-led-switch, optocoupler-signal,
l293d-motor-control, l293d-speed-pwm
POWER / REGULATOR (3):
power-supply-7805, lm317-adjustable-psu, battery-voltage-monitor
BOARD-SPECIFIC (4):
esp32-dual-adc, mega-multi-led, nano-sensor-station,
esp32-pwm-led-rgb (uses ESP32 LEDC peripheral)
The new examples are appended to exampleProjects[] in examples.ts so the
existing gallery and category filters pick them up automatically.
test/test_circuit/test/spice_examples.test.js validates each example's
analog topology in ngspice — 45 individual assertions covering all 40
examples (plus extra cases for NTC/Zener sweeps and L293D direction).
Sandbox tally: 164 -> 209 tests, 7.9s runtime, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
David Montero Crespo