From 81837eedb9e0ea3925ccad92d8a436986720d5ce Mon Sep 17 00:00:00 2001
From: David Montero Crespo <davidmonterocrespo24@gmail.com>
Date: Mon, 18 May 2026 21:47:45 -0300
Subject: [PATCH] fix(spice+pipeline): LED visualization, INPUT_PULLUP,
 ESP32-C3, PWM fade, examples
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End-to-end pipeline fixes uncovered while auditing the /examples gallery.
Each bug shipped past green unit + snapshot tests because none of those run
firmware + render LEDs. Added scripts/visual-led-test.mjs as a CDP-driven
visual harness that loads each example, runs the simulator, samples
`wokwi-led.brightness`, and asserts toggle / gradient / initial-off
invariants — exits non-zero on any regression.

Frontend simulator
- PinManager.updatePort: new optional ddrMask param. A pin is added to
  `outputPins` only if the DDR bit is set, so the PORTx write that
  enables INPUT_PULLUP (DDR=0, PORT=1) no longer falsely marks the pin
  as MCU output. AVRSimulator now reads DDRB/C/D (0x24/0x27/0x2A on
  Uno/Nano, 0x37 on ATtiny85, per-port table on Mega) and forwards it.
- AVRSimulator: pass DDR mask alongside every port-listener fire.
- BasicParts pushbutton{,-6mm}: seed pin HIGH in attachEvents so
  `digitalRead()` returns HIGH while idle. avr8js doesn't auto-simulate
  INPUT_PULLUP — without this the firmware reads LOW from boot and
  thinks the button is permanently pressed (the "LED is always on,
  pressing does nothing" UX bug).
- connectMcuEdgesToService: suppress synthetic digital edges on pins
  with active PWM, AND subscribe to onPwmChange to re-tick the netlist
  on duty changes. Fade-LED now produces a true gradient (6 distinct
  brightness levels across a fade cycle) instead of a binary 0/full
  toggle.
- CircuitSimulationService.handleMcuEdge: replace single-slot
  pendingMcuEdge with a per-pin Map. Multiple pins toggling during the
  same in-flight tick used to overwrite each other; now every pin's
  most-recent edge replays after the tick. Fixes Traffic-Light RED→
  YELLOW→GREEN sequencing.
- NetlistBuilder: new sanitizeSpiceId() helper replaces hyphens with
  underscores in V-source names. ngspice's interactive `alter` command
  treats `-` as an operator and silently no-ops on hyphenated source
  names, so mid-simulation MCU pin transitions stopped propagating
  after the first solve. MixedModeScheduler.onMcuPinChange and
  CircuitSimulationService self-heal use the same sanitizer so names
  stay consistent across emit/alter/lookup. Also added a regex-based
  fallback in step 2 so any board pin matching `GND.\d+` canonicalises
  to net "0" — ESP32-C3 dev kits expose up to 10 GND pins and the
  per-board `groundPinNames` list missed several, leaving wires
  floating instead of grounded.
- collectPinStates: emit V-sources only for pins in `outputPins`, not
  every wired board pin. Leaves INPUT pins (analog sensors on A0,
  pull-down dividers, etc.) free for the SPICE solver instead of being
  shorted to 0 V by an ideal MCU V-source.
- start.ts: extended __spiceDebug to also expose outputPinsByBoard +
  nodeVoltages + pinNetMapEntries for the visual harness.
- ESP32 / RP2040 / RISC-V / C3 simulators: pass `'mcu'` source flag to
  triggerPinChange / setPinState so the new outputPins tracking fires
  on those boards too (was AVR-only before).
- useSimulatorStore: stopBoard/resetBoard call pm.resetPinStates() so
  outputPins clears between runs; Esp32Bridge.onPinChange passes the
  `'mcu'` flag in all three places it's wired.
- types/board.ts: ATtiny85 FQBN `clock=internal16mhz` →
  `clock=16pll` (ATTinyCore 1.5.2 renamed the option).

Backend
- esp-idf-template/main/CMakeLists.txt: skip the
  `-DLED_BUILTIN=2` fallback for esp32c3 and esp32s3 targets. Both
  variants already define LED_BUILTIN in pins_arduino.h via a
  self-define macro (`#define LED_BUILTIN LED_BUILTIN` + `static const
  uint8_t LED_BUILTIN = ...;`). Pre-defining the symbol from the
  command line expanded the static-const declaration to
  `static const uint8_t 2 = ...;` — a syntax error that broke every
  ESP32-C3 / S3 build (`expected unqualified-id before numeric
  constant`).

Examples
- examples.ts: bulk-fix 72 wire endpoints that referenced
  `componentId: 'nano-rp2040'` / `'esp32-c3'` etc. (boards that don't
  exist on the canvas). Replaced with `'arduino-uno'` (the canvas
  board-id convention) and converted `D<n>` pin names to `GP<n>` for
  Pico-style boards. Affects pico-blink, pico-i2c-scanner,
  pico-i2c-rtc-read, pico-spi-loopback, c3-blink and others.

Tests
- scripts/visual-led-test.mjs: CDP-driven harness. Default suite covers
  Blink (single-pin), Button (idle-OFF invariant — catches the
  INPUT_PULLUP regression), Traffic-Light (multi-pin sequencing),
  Fade-LED (PWM gradient — ≥3 distinct levels), RGB-LED (≥3 PWM pins
  driven). Run via `npm --prefix frontend run test:visual` against a
  Chrome on `:9222` + vite on `:5174` + backend on `:8001`.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---
 .../esp-idf-template/main/CMakeLists.txt      |  14 +-
 frontend/package.json                         |   5 +-
 frontend/src/data/examples.ts                 | 304 +++++++++---------
 frontend/src/simulation/AVRSimulator.ts       |  24 +-
 frontend/src/simulation/Esp32C3Simulator.ts   |   2 +-
 frontend/src/simulation/PinManager.ts         |  56 +++-
 frontend/src/simulation/RP2040Simulator.ts    |   2 +-
 frontend/src/simulation/RiscVSimulator.ts     |   2 +-
 frontend/src/simulation/parts/BasicParts.ts   |  11 +
 .../spice/CircuitSimulationService.ts         |  53 ++-
 .../simulation/spice/MixedModeScheduler.ts    |   6 +-
 .../src/simulation/spice/NetlistBuilder.ts    |  37 ++-
 .../src/simulation/spice/collectPinStates.ts  |  30 +-
 .../spice/connectMcuEdgesToService.ts         |  26 ++
 frontend/src/simulation/spice/start.ts        |  33 +-
 frontend/src/store/useSimulatorStore.ts       |  27 +-
 frontend/src/types/board.ts                   |   2 +-
 scripts/visual-led-test.mjs                   | 297 +++++++++++++++++
 18 files changed, 707 insertions(+), 224 deletions(-)
 create mode 100644 scripts/visual-led-test.mjs

diff --git a/backend/app/services/esp-idf-template/main/CMakeLists.txt b/backend/app/services/esp-idf-template/main/CMakeLists.txt
index 8638bd12..7319be84 100644
--- a/backend/app/services/esp-idf-template/main/CMakeLists.txt
+++ b/backend/app/services/esp-idf-template/main/CMakeLists.txt
@@ -55,8 +55,18 @@ if(DEFINED ENV{ARDUINO_ESP32_PATH})
     # for ESP32-CAM where GPIO 2 isn't broken out, the user should use an
     # explicit pin number — but this default keeps the new-project flow
     # smooth.
-    target_compile_definitions(${COMPONENT_LIB} PRIVATE
-        "LED_BUILTIN=2")
+    #
+    # SKIP on ESP32-C3 and S3 variants: their pins_arduino.h DOES define
+    # LED_BUILTIN already (as `static const uint8_t LED_BUILTIN = ...;`
+    # plus `#define LED_BUILTIN LED_BUILTIN`). Pre-defining it from the
+    # command line clashes with the self-define: the preprocessor expands
+    # `static const uint8_t LED_BUILTIN = ...` to `static const uint8_t 2 = ...`
+    # which is a syntax error. Only set the fallback for the generic ESP32
+    # Xtensa variant that genuinely lacks the symbol.
+    if(NOT IDF_TARGET STREQUAL "esp32c3" AND NOT IDF_TARGET STREQUAL "esp32s3")
+        target_compile_definitions(${COMPONENT_LIB} PRIVATE
+            "LED_BUILTIN=2")
+    endif()
 else()
     # Pure ESP-IDF mode: main.c #includes sketch_translated.c
     idf_component_register(
diff --git a/frontend/package.json b/frontend/package.json
index 25632b46..23602e2c 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -26,7 +26,8 @@
     "test:coverage": "vitest run --coverage",
     "test:ui": "vitest --ui",
     "tsc": "tsc -b",
-    "test:libraries": "RUN_LIBRARY_TESTS=1 vitest run src/__tests__/library-compile.integration.test.ts"
+    "test:libraries": "RUN_LIBRARY_TESTS=1 vitest run src/__tests__/library-compile.integration.test.ts",
+    "test:visual": "node ../scripts/visual-led-test.mjs"
   },
   "dependencies": {
     "@google/genai": "^0.6.0",
@@ -78,4 +79,4 @@
     "vite": "^7.3.1",
     "vitest": "^4.0.18"
   }
-}
\ No newline at end of file
+}
diff --git a/frontend/src/data/examples.ts b/frontend/src/data/examples.ts
index 5a3ec016..e807dc81 100644
--- a/frontend/src/data/examples.ts
+++ b/frontend/src/data/examples.ts
@@ -2000,7 +2000,7 @@ void loop() {
     wires: [
       {
         id: 'w1',
-        start: { componentId: 'nano-rp2040', pinName: 'D2' },
+        start: { componentId: 'arduino-uno', pinName: 'GP25' },
         end: { componentId: 'led-blink', pinName: 'A' },
         color: '#00cc00',
       },
@@ -2013,7 +2013,7 @@ void loop() {
       {
         id: 'w3',
         start: { componentId: 'r1', pinName: '2' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2062,14 +2062,14 @@ void loop() {
     wires: [
       {
         id: 'w1',
-        start: { componentId: 'nano-rp2040', pinName: 'TX' },
+        start: { componentId: 'arduino-uno', pinName: 'TX' },
         end: { componentId: 'led-rx', pinName: 'A' },
         color: '#ff8800',
       },
       {
         id: 'w2',
         start: { componentId: 'led-rx', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2126,7 +2126,7 @@ void loop() {
     wires: [
       {
         id: 'w1',
-        start: { componentId: 'nano-rp2040', pinName: 'D2' },
+        start: { componentId: 'arduino-uno', pinName: 'GP2' },
         end: { componentId: 'led-status', pinName: 'A' },
         color: '#00cc00',
       },
@@ -2139,7 +2139,7 @@ void loop() {
       {
         id: 'w3',
         start: { componentId: 'r1', pinName: '2' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2207,26 +2207,26 @@ void loop() {
     wires: [
       {
         id: 'w1',
-        start: { componentId: 'nano-rp2040', pinName: 'D12' },
+        start: { componentId: 'arduino-uno', pinName: 'GP12' },
         end: { componentId: 'led-scan', pinName: 'A' },
         color: '#4488ff',
       },
       {
         id: 'w2',
-        start: { componentId: 'nano-rp2040', pinName: 'D10' },
+        start: { componentId: 'arduino-uno', pinName: 'GP10' },
         end: { componentId: 'led-found', pinName: 'A' },
         color: '#00cc00',
       },
       {
         id: 'w3',
         start: { componentId: 'led-scan', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w4',
         start: { componentId: 'led-found', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2299,26 +2299,26 @@ void loop() {
     wires: [
       {
         id: 'w-sda',
-        start: { componentId: 'nano-rp2040', pinName: 'D12' },
+        start: { componentId: 'arduino-uno', pinName: 'GP12' },
         end: { componentId: 'led-i2c', pinName: 'A' },
         color: '#4488ff',
       },
       {
         id: 'w-scl',
-        start: { componentId: 'nano-rp2040', pinName: 'D10' },
+        start: { componentId: 'arduino-uno', pinName: 'GP10' },
         end: { componentId: 'led-rtc', pinName: 'A' },
         color: '#ffaa00',
       },
       {
         id: 'w-sda-gnd',
         start: { componentId: 'led-i2c', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-scl-gnd',
         start: { componentId: 'led-rtc', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2409,26 +2409,26 @@ void loop() {
     wires: [
       {
         id: 'w-sda',
-        start: { componentId: 'nano-rp2040', pinName: 'D12' },
+        start: { componentId: 'arduino-uno', pinName: 'GP12' },
         end: { componentId: 'led-write', pinName: 'A' },
         color: '#ff4444',
       },
       {
         id: 'w-scl',
-        start: { componentId: 'nano-rp2040', pinName: 'D10' },
+        start: { componentId: 'arduino-uno', pinName: 'GP10' },
         end: { componentId: 'led-read', pinName: 'A' },
         color: '#00cc00',
       },
       {
         id: 'w-write-gnd',
         start: { componentId: 'led-write', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-read-gnd',
         start: { componentId: 'led-read', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2491,38 +2491,38 @@ void loop() {
     wires: [
       {
         id: 'w-mosi',
-        start: { componentId: 'nano-rp2040', pinName: 'D7' },
+        start: { componentId: 'arduino-uno', pinName: 'GP7' },
         end: { componentId: 'led-mosi', pinName: 'A' },
         color: '#ff4444',
       },
       {
         id: 'w-miso',
-        start: { componentId: 'nano-rp2040', pinName: 'D4' },
+        start: { componentId: 'arduino-uno', pinName: 'GP4' },
         end: { componentId: 'led-miso', pinName: 'A' },
         color: '#00cc00',
       },
       {
         id: 'w-sck',
-        start: { componentId: 'nano-rp2040', pinName: 'D6' },
+        start: { componentId: 'arduino-uno', pinName: 'GP6' },
         end: { componentId: 'led-sck', pinName: 'A' },
         color: '#ffaa00',
       },
       {
         id: 'w-mosi-gnd',
         start: { componentId: 'led-mosi', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-miso-gnd',
         start: { componentId: 'led-miso', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-sck-gnd',
         start: { componentId: 'led-sck', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2576,50 +2576,50 @@ void loop() {
     wires: [
       {
         id: 'w-a0',
-        start: { componentId: 'nano-rp2040', pinName: 'A0' },
+        start: { componentId: 'arduino-uno', pinName: 'A0' },
         end: { componentId: 'pot-a0', pinName: 'SIG' },
         color: '#4488ff',
       },
       {
         id: 'w-a1',
-        start: { componentId: 'nano-rp2040', pinName: 'A1' },
+        start: { componentId: 'arduino-uno', pinName: 'A1' },
         end: { componentId: 'pot-a1', pinName: 'SIG' },
         color: '#44cc44',
       },
       {
         id: 'w-temp',
-        start: { componentId: 'nano-rp2040', pinName: 'D2' },
+        start: { componentId: 'arduino-uno', pinName: 'GP2' },
         end: { componentId: 'led-temp', pinName: 'A' },
         color: '#ff4444',
       },
       {
         id: 'w-pot-a0-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'pot-a0', pinName: 'VCC' },
         color: '#ff0000',
       },
       {
         id: 'w-pot-a0-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pot-a0', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'w-pot-a1-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'pot-a1', pinName: 'VCC' },
         color: '#ff0000',
       },
       {
         id: 'w-pot-a1-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pot-a1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'w-temp-gnd',
         start: { componentId: 'led-temp', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -2750,55 +2750,55 @@ void loop() {
     wires: [
       {
         id: 'w-i2c',
-        start: { componentId: 'nano-rp2040', pinName: 'D12' },
+        start: { componentId: 'arduino-uno', pinName: 'GP12' },
         end: { componentId: 'led-i2c', pinName: 'A' },
         color: '#4488ff',
       },
       {
         id: 'w-spi',
-        start: { componentId: 'nano-rp2040', pinName: 'D7' },
+        start: { componentId: 'arduino-uno', pinName: 'GP7' },
         end: { componentId: 'led-spi', pinName: 'A' },
         color: '#ffaa00',
       },
       {
         id: 'w-adc',
-        start: { componentId: 'nano-rp2040', pinName: 'A0' },
+        start: { componentId: 'arduino-uno', pinName: 'A0' },
         end: { componentId: 'pot-adc', pinName: 'SIG' },
         color: '#cc44cc',
       },
       {
         id: 'w-gpio',
-        start: { componentId: 'nano-rp2040', pinName: 'D2' },
+        start: { componentId: 'arduino-uno', pinName: 'GP2' },
         end: { componentId: 'led-gpio', pinName: 'A' },
         color: '#00cc00',
       },
       {
         id: 'w-i2c-gnd',
         start: { componentId: 'led-i2c', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-spi-gnd',
         start: { componentId: 'led-spi', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-gpio-gnd',
         start: { componentId: 'led-gpio', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'w-pot-adc-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'pot-adc', pinName: 'VCC' },
         color: '#ff0000',
       },
       {
         id: 'w-pot-adc-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pot-adc', pinName: 'GND' },
         color: '#000000',
       },
@@ -2847,7 +2847,7 @@ void loop() {
       // GPIO4 → LED anode
       {
         id: 'w-gpio4-led',
-        start: { componentId: 'esp32', pinName: '4' },
+        start: { componentId: 'arduino-uno', pinName: '4' },
         end: { componentId: 'led-ext', pinName: 'A' },
         color: '#e74c3c',
       },
@@ -2855,7 +2855,7 @@ void loop() {
       {
         id: 'w-gnd',
         start: { componentId: 'led-ext', pinName: 'C' },
-        end: { componentId: 'esp32', pinName: 'GND' },
+        end: { componentId: 'arduino-uno', pinName: 'GND' },
         color: '#2c3e50',
       },
     ],
@@ -4035,7 +4035,7 @@ void loop() {
     wires: [
       {
         id: 'c3w1',
-        start: { componentId: 'esp32-c3', pinName: '8' },
+        start: { componentId: 'arduino-uno', pinName: '8' },
         end: { componentId: 'c3-led1', pinName: 'A' },
         color: '#22cc22',
       },
@@ -4048,7 +4048,7 @@ void loop() {
       {
         id: 'c3w3',
         start: { componentId: 'c3-r1', pinName: '2' },
-        end: { componentId: 'esp32-c3', pinName: 'GND.9' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.9' },
         color: '#000000',
       },
     ],
@@ -4131,26 +4131,26 @@ void loop() {
     wires: [
       {
         id: 'c3-rw1',
-        start: { componentId: 'esp32-c3', pinName: '6' },
+        start: { componentId: 'arduino-uno', pinName: '6' },
         end: { componentId: 'c3-rgb1', pinName: 'R' },
         color: '#ff2222',
       },
       {
         id: 'c3-rw2',
-        start: { componentId: 'esp32-c3', pinName: '7' },
+        start: { componentId: 'arduino-uno', pinName: '7' },
         end: { componentId: 'c3-rgb1', pinName: 'G' },
         color: '#22cc22',
       },
       {
         id: 'c3-rw3',
-        start: { componentId: 'esp32-c3', pinName: '8' },
+        start: { componentId: 'arduino-uno', pinName: '8' },
         end: { componentId: 'c3-rgb1', pinName: 'B' },
         color: '#2244ff',
       },
       {
         id: 'c3-rw4',
         start: { componentId: 'c3-rgb1', pinName: 'COM' },
-        end: { componentId: 'esp32-c3', pinName: 'GND.8' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.8' },
         color: '#000000',
       },
     ],
@@ -4191,26 +4191,26 @@ void loop() {
     wires: [
       {
         id: 'c3-bw1',
-        start: { componentId: 'esp32-c3', pinName: '9' },
+        start: { componentId: 'arduino-uno', pinName: '9' },
         end: { componentId: 'c3-btn1', pinName: '1a' },
         color: '#00aaff',
       },
       {
         id: 'c3-bw2',
-        start: { componentId: 'esp32-c3', pinName: '8' },
+        start: { componentId: 'arduino-uno', pinName: '8' },
         end: { componentId: 'c3-led-btn', pinName: 'A' },
         color: '#2244ff',
       },
       {
         id: 'c3-bw3',
         start: { componentId: 'c3-led-btn', pinName: 'C' },
-        end: { componentId: 'esp32-c3', pinName: 'GND.8' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.8' },
         color: '#000000',
       },
       {
         id: 'c3-bw4',
         start: { componentId: 'c3-btn1', pinName: '1b' },
-        end: { componentId: 'esp32-c3', pinName: 'GND.9' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.9' },
         color: '#000000',
       },
     ],
@@ -4412,50 +4412,50 @@ void loop() {
     wires: [
       {
         id: 'ps-a',
-        start: { componentId: 'nano-rp2040', pinName: 'GP2' },
+        start: { componentId: 'arduino-uno', pinName: 'GP2' },
         end: { componentId: 'pico-seg1', pinName: 'A' },
         color: '#ff4444',
       },
       {
         id: 'ps-b',
-        start: { componentId: 'nano-rp2040', pinName: 'GP3' },
+        start: { componentId: 'arduino-uno', pinName: 'GP3' },
         end: { componentId: 'pico-seg1', pinName: 'B' },
         color: '#ff8800',
       },
       {
         id: 'ps-c',
-        start: { componentId: 'nano-rp2040', pinName: 'GP4' },
+        start: { componentId: 'arduino-uno', pinName: 'GP4' },
         end: { componentId: 'pico-seg1', pinName: 'C' },
         color: '#ffcc00',
       },
       {
         id: 'ps-d',
-        start: { componentId: 'nano-rp2040', pinName: 'GP5' },
+        start: { componentId: 'arduino-uno', pinName: 'GP5' },
         end: { componentId: 'pico-seg1', pinName: 'D' },
         color: '#44cc44',
       },
       {
         id: 'ps-e',
-        start: { componentId: 'nano-rp2040', pinName: 'GP6' },
+        start: { componentId: 'arduino-uno', pinName: 'GP6' },
         end: { componentId: 'pico-seg1', pinName: 'E' },
         color: '#4488ff',
       },
       {
         id: 'ps-f',
-        start: { componentId: 'nano-rp2040', pinName: 'GP7' },
+        start: { componentId: 'arduino-uno', pinName: 'GP7' },
         end: { componentId: 'pico-seg1', pinName: 'F' },
         color: '#aa44ff',
       },
       {
         id: 'ps-g',
-        start: { componentId: 'nano-rp2040', pinName: 'GP8' },
+        start: { componentId: 'arduino-uno', pinName: 'GP8' },
         end: { componentId: 'pico-seg1', pinName: 'G' },
         color: '#ffffff',
       },
       {
         id: 'ps-gnd',
         start: { componentId: 'pico-seg1', pinName: 'COM' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -4519,50 +4519,50 @@ void loop() {
     wires: [
       {
         id: 'es-a',
-        start: { componentId: 'esp32', pinName: '12' },
+        start: { componentId: 'arduino-uno', pinName: '12' },
         end: { componentId: 'esp-seg1', pinName: 'A' },
         color: '#ff4444',
       },
       {
         id: 'es-b',
-        start: { componentId: 'esp32', pinName: '13' },
+        start: { componentId: 'arduino-uno', pinName: '13' },
         end: { componentId: 'esp-seg1', pinName: 'B' },
         color: '#ff8800',
       },
       {
         id: 'es-c',
-        start: { componentId: 'esp32', pinName: '14' },
+        start: { componentId: 'arduino-uno', pinName: '14' },
         end: { componentId: 'esp-seg1', pinName: 'C' },
         color: '#ffcc00',
       },
       {
         id: 'es-d',
-        start: { componentId: 'esp32', pinName: '25' },
+        start: { componentId: 'arduino-uno', pinName: '25' },
         end: { componentId: 'esp-seg1', pinName: 'D' },
         color: '#44cc44',
       },
       {
         id: 'es-e',
-        start: { componentId: 'esp32', pinName: '26' },
+        start: { componentId: 'arduino-uno', pinName: '26' },
         end: { componentId: 'esp-seg1', pinName: 'E' },
         color: '#4488ff',
       },
       {
         id: 'es-f',
-        start: { componentId: 'esp32', pinName: '27' },
+        start: { componentId: 'arduino-uno', pinName: '27' },
         end: { componentId: 'esp-seg1', pinName: 'F' },
         color: '#aa44ff',
       },
       {
         id: 'es-g',
-        start: { componentId: 'esp32', pinName: '32' },
+        start: { componentId: 'arduino-uno', pinName: '32' },
         end: { componentId: 'esp-seg1', pinName: 'G' },
         color: '#ffffff',
       },
       {
         id: 'es-gnd',
         start: { componentId: 'esp-seg1', pinName: 'COM' },
-        end: { componentId: 'esp32', pinName: 'GND' },
+        end: { componentId: 'arduino-uno', pinName: 'GND' },
         color: '#000000',
       },
     ],
@@ -4719,26 +4719,26 @@ void loop() {
     wires: [
       {
         id: 'pb-btn',
-        start: { componentId: 'nano-rp2040', pinName: 'GP2' },
+        start: { componentId: 'arduino-uno', pinName: 'GP2' },
         end: { componentId: 'pico-btn1', pinName: '1a' },
         color: '#00aaff',
       },
       {
         id: 'pb-led',
-        start: { componentId: 'nano-rp2040', pinName: 'GP3' },
+        start: { componentId: 'arduino-uno', pinName: 'GP3' },
         end: { componentId: 'pico-led-btn', pinName: 'A' },
         color: '#ffcc00',
       },
       {
         id: 'pb-led-gnd',
         start: { componentId: 'pico-led-btn', pinName: 'C' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
       {
         id: 'pb-btn-gnd',
         start: { componentId: 'pico-btn1', pinName: '1b' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -4785,26 +4785,26 @@ void loop() {
     wires: [
       {
         id: 'pr-r',
-        start: { componentId: 'nano-rp2040', pinName: 'GP6' },
+        start: { componentId: 'arduino-uno', pinName: 'GP6' },
         end: { componentId: 'pico-rgb1', pinName: 'R' },
         color: '#ff2222',
       },
       {
         id: 'pr-g',
-        start: { componentId: 'nano-rp2040', pinName: 'GP7' },
+        start: { componentId: 'arduino-uno', pinName: 'GP7' },
         end: { componentId: 'pico-rgb1', pinName: 'G' },
         color: '#22cc22',
       },
       {
         id: 'pr-b',
-        start: { componentId: 'nano-rp2040', pinName: 'GP8' },
+        start: { componentId: 'arduino-uno', pinName: 'GP8' },
         end: { componentId: 'pico-rgb1', pinName: 'B' },
         color: '#2244ff',
       },
       {
         id: 'pr-gnd',
         start: { componentId: 'pico-rgb1', pinName: 'COM' },
-        end: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        end: { componentId: 'arduino-uno', pinName: 'GND.1' },
         color: '#000000',
       },
     ],
@@ -5287,19 +5287,19 @@ void loop() {
     wires: [
       {
         id: 'pcd-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3.3V' },
+        start: { componentId: 'arduino-uno', pinName: '3.3V' },
         end: { componentId: 'pico-dht1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'pcd-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pico-dht1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'pcd-sda',
-        start: { componentId: 'nano-rp2040', pinName: 'GP7' },
+        start: { componentId: 'arduino-uno', pinName: 'GP7' },
         end: { componentId: 'pico-dht1', pinName: 'SDA' },
         color: '#22aaff',
       },
@@ -5352,25 +5352,25 @@ void loop() {
     wires: [
       {
         id: 'pcs-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3.3V' },
+        start: { componentId: 'arduino-uno', pinName: '3.3V' },
         end: { componentId: 'pico-sr1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'pcs-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pico-sr1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'pcs-trig',
-        start: { componentId: 'nano-rp2040', pinName: 'D5' },
+        start: { componentId: 'arduino-uno', pinName: 'GP5' },
         end: { componentId: 'pico-sr1', pinName: 'TRIG' },
         color: '#ff8800',
       },
       {
         id: 'pcs-echo',
-        start: { componentId: 'nano-rp2040', pinName: 'D6' },
+        start: { componentId: 'arduino-uno', pinName: 'GP6' },
         end: { componentId: 'pico-sr1', pinName: 'ECHO' },
         color: '#22cc22',
       },
@@ -5420,19 +5420,19 @@ void loop() {
     wires: [
       {
         id: 'pp-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3.3V' },
+        start: { componentId: 'arduino-uno', pinName: '3.3V' },
         end: { componentId: 'pico-pir1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'pp-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pico-pir1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'pp-out',
-        start: { componentId: 'nano-rp2040', pinName: 'D4' },
+        start: { componentId: 'arduino-uno', pinName: 'GP4' },
         end: { componentId: 'pico-pir1', pinName: 'OUT' },
         color: '#ffcc00',
       },
@@ -5473,19 +5473,19 @@ void loop() {
     wires: [
       {
         id: 'psv-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3.3V' },
+        start: { componentId: 'arduino-uno', pinName: '3.3V' },
         end: { componentId: 'pico-sv1', pinName: 'V+' },
         color: '#ff4444',
       },
       {
         id: 'psv-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pico-sv1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'psv-pwm',
-        start: { componentId: 'nano-rp2040', pinName: 'D3' },
+        start: { componentId: 'arduino-uno', pinName: 'GP3' },
         end: { componentId: 'pico-sv1', pinName: 'PWM' },
         color: '#ff8800',
       },
@@ -5542,19 +5542,19 @@ void loop() {
     wires: [
       {
         id: 'pnt-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3.3V' },
+        start: { componentId: 'arduino-uno', pinName: '3.3V' },
         end: { componentId: 'pico-ntc1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'pnt-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pico-ntc1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'pnt-out',
-        start: { componentId: 'nano-rp2040', pinName: 'A0' },
+        start: { componentId: 'arduino-uno', pinName: 'A0' },
         end: { componentId: 'pico-ntc1', pinName: 'OUT' },
         color: '#aa44ff',
       },
@@ -5604,31 +5604,31 @@ void loop() {
     wires: [
       {
         id: 'pj-vcc',
-        start: { componentId: 'nano-rp2040', pinName: '3.3V' },
+        start: { componentId: 'arduino-uno', pinName: '3.3V' },
         end: { componentId: 'pico-joy1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'pj-gnd',
-        start: { componentId: 'nano-rp2040', pinName: 'GND.1' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.1' },
         end: { componentId: 'pico-joy1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'pj-vert',
-        start: { componentId: 'nano-rp2040', pinName: 'A0' },
+        start: { componentId: 'arduino-uno', pinName: 'A0' },
         end: { componentId: 'pico-joy1', pinName: 'VERT' },
         color: '#22aaff',
       },
       {
         id: 'pj-horz',
-        start: { componentId: 'nano-rp2040', pinName: 'A1' },
+        start: { componentId: 'arduino-uno', pinName: 'A1' },
         end: { componentId: 'pico-joy1', pinName: 'HORZ' },
         color: '#22cc44',
       },
       {
         id: 'pj-sel',
-        start: { componentId: 'nano-rp2040', pinName: 'D4' },
+        start: { componentId: 'arduino-uno', pinName: 'GP4' },
         end: { componentId: 'pico-joy1', pinName: 'SEL' },
         color: '#aa44ff',
       },
@@ -5688,19 +5688,19 @@ void loop() {
     wires: [
       {
         id: 'e32d-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-dht1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32d-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-dht1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32d-sda',
-        start: { componentId: 'esp32', pinName: '4' },
+        start: { componentId: 'arduino-uno', pinName: '4' },
         end: { componentId: 'e32-dht1', pinName: 'SDA' },
         color: '#22aaff',
       },
@@ -5752,25 +5752,25 @@ void loop() {
     wires: [
       {
         id: 'e32s-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-sr1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32s-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-sr1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32s-trig',
-        start: { componentId: 'esp32', pinName: '18' },
+        start: { componentId: 'arduino-uno', pinName: '18' },
         end: { componentId: 'e32-sr1', pinName: 'TRIG' },
         color: '#ff8800',
       },
       {
         id: 'e32s-echo',
-        start: { componentId: 'esp32', pinName: '19' },
+        start: { componentId: 'arduino-uno', pinName: '19' },
         end: { componentId: 'e32-sr1', pinName: 'ECHO' },
         color: '#22cc22',
       },
@@ -5825,25 +5825,25 @@ void loop() {
     wires: [
       {
         id: 'e32m-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-mpu1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32m-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-mpu1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32m-sda',
-        start: { componentId: 'esp32', pinName: '21' },
+        start: { componentId: 'arduino-uno', pinName: '21' },
         end: { componentId: 'e32-mpu1', pinName: 'SDA' },
         color: '#22aaff',
       },
       {
         id: 'e32m-scl',
-        start: { componentId: 'esp32', pinName: '22' },
+        start: { componentId: 'arduino-uno', pinName: '22' },
         end: { componentId: 'e32-mpu1', pinName: 'SCL' },
         color: '#ff8800',
       },
@@ -5898,19 +5898,19 @@ void loop() {
     wires: [
       {
         id: 'e32p-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-pir1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32p-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-pir1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32p-out',
-        start: { componentId: 'esp32', pinName: '5' },
+        start: { componentId: 'arduino-uno', pinName: '5' },
         end: { componentId: 'e32-pir1', pinName: 'OUT' },
         color: '#ffcc00',
       },
@@ -5958,37 +5958,37 @@ void loop() {
     wires: [
       {
         id: 'e32sv-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-sv1', pinName: 'V+' },
         color: '#ff4444',
       },
       {
         id: 'e32sv-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-sv1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32sv-pwm',
-        start: { componentId: 'esp32', pinName: '13' },
+        start: { componentId: 'arduino-uno', pinName: '13' },
         end: { componentId: 'e32-sv1', pinName: 'PWM' },
         color: '#ff8800',
       },
       {
         id: 'e32pt-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-pot1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32pt-gnd',
-        start: { componentId: 'esp32', pinName: 'GND2' },
+        start: { componentId: 'arduino-uno', pinName: 'GND2' },
         end: { componentId: 'e32-pot1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32pt-sig',
-        start: { componentId: 'esp32', pinName: '34' },
+        start: { componentId: 'arduino-uno', pinName: '34' },
         end: { componentId: 'e32-pot1', pinName: 'SIG' },
         color: '#aa44ff',
       },
@@ -6035,31 +6035,31 @@ void loop() {
     wires: [
       {
         id: 'e32j-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-joy1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32j-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-joy1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32j-vert',
-        start: { componentId: 'esp32', pinName: '34' },
+        start: { componentId: 'arduino-uno', pinName: '34' },
         end: { componentId: 'e32-joy1', pinName: 'VERT' },
         color: '#22aaff',
       },
       {
         id: 'e32j-horz',
-        start: { componentId: 'esp32', pinName: '35' },
+        start: { componentId: 'arduino-uno', pinName: '35' },
         end: { componentId: 'e32-joy1', pinName: 'HORZ' },
         color: '#22cc44',
       },
       {
         id: 'e32j-sel',
-        start: { componentId: 'esp32', pinName: '15' },
+        start: { componentId: 'arduino-uno', pinName: '15' },
         end: { componentId: 'e32-joy1', pinName: 'SEL' },
         color: '#aa44ff',
       },
@@ -6120,19 +6120,19 @@ void loop() {
     wires: [
       {
         id: 'c3d-vcc',
-        start: { componentId: 'esp32-c3', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'c3-dht1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'c3d-gnd',
-        start: { componentId: 'esp32-c3', pinName: 'GND.9' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.9' },
         end: { componentId: 'c3-dht1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'c3d-sda',
-        start: { componentId: 'esp32-c3', pinName: '3' },
+        start: { componentId: 'arduino-uno', pinName: '3' },
         end: { componentId: 'c3-dht1', pinName: 'SDA' },
         color: '#22aaff',
       },
@@ -6182,25 +6182,25 @@ void loop() {
     wires: [
       {
         id: 'c3s-vcc',
-        start: { componentId: 'esp32-c3', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'c3-sr1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'c3s-gnd',
-        start: { componentId: 'esp32-c3', pinName: 'GND.9' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.9' },
         end: { componentId: 'c3-sr1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'c3s-trig',
-        start: { componentId: 'esp32-c3', pinName: '5' },
+        start: { componentId: 'arduino-uno', pinName: '5' },
         end: { componentId: 'c3-sr1', pinName: 'TRIG' },
         color: '#ff8800',
       },
       {
         id: 'c3s-echo',
-        start: { componentId: 'esp32-c3', pinName: '6' },
+        start: { componentId: 'arduino-uno', pinName: '6' },
         end: { componentId: 'c3-sr1', pinName: 'ECHO' },
         color: '#22cc22',
       },
@@ -6252,19 +6252,19 @@ void loop() {
     wires: [
       {
         id: 'c3p-vcc',
-        start: { componentId: 'esp32-c3', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'c3-pir1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'c3p-gnd',
-        start: { componentId: 'esp32-c3', pinName: 'GND.9' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.9' },
         end: { componentId: 'c3-pir1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'c3p-out',
-        start: { componentId: 'esp32-c3', pinName: '7' },
+        start: { componentId: 'arduino-uno', pinName: '7' },
         end: { componentId: 'c3-pir1', pinName: 'OUT' },
         color: '#ffcc00',
       },
@@ -6305,19 +6305,19 @@ void loop() {
     wires: [
       {
         id: 'c3sv-vcc',
-        start: { componentId: 'esp32-c3', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'c3-sv1', pinName: 'V+' },
         color: '#ff4444',
       },
       {
         id: 'c3sv-gnd',
-        start: { componentId: 'esp32-c3', pinName: 'GND.9' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.9' },
         end: { componentId: 'c3-sv1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'c3sv-pwm',
-        start: { componentId: 'esp32-c3', pinName: '10' },
+        start: { componentId: 'arduino-uno', pinName: '10' },
         end: { componentId: 'c3-sv1', pinName: 'PWM' },
         color: '#ff8800',
       },
@@ -6873,25 +6873,25 @@ void loop() {
     wires: [
       {
         id: 'e32b-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-bmp1', pinName: 'VCC' },
         color: '#ff4444',
       },
       {
         id: 'e32b-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-bmp1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32b-sda',
-        start: { componentId: 'esp32', pinName: '21' },
+        start: { componentId: 'arduino-uno', pinName: '21' },
         end: { componentId: 'e32-bmp1', pinName: 'SDA' },
         color: '#22aaff',
       },
       {
         id: 'e32b-scl',
-        start: { componentId: 'esp32', pinName: '22' },
+        start: { componentId: 'arduino-uno', pinName: '22' },
         end: { componentId: 'e32-bmp1', pinName: 'SCL' },
         color: '#ff8800',
       },
@@ -6959,25 +6959,25 @@ void loop() {
     wires: [
       {
         id: 'e32o-vcc',
-        start: { componentId: 'esp32', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'e32-oled1', pinName: '3V3' },
         color: '#ff4444',
       },
       {
         id: 'e32o-gnd',
-        start: { componentId: 'esp32', pinName: 'GND' },
+        start: { componentId: 'arduino-uno', pinName: 'GND' },
         end: { componentId: 'e32-oled1', pinName: 'GND' },
         color: '#000000',
       },
       {
         id: 'e32o-sda',
-        start: { componentId: 'esp32', pinName: '21' },
+        start: { componentId: 'arduino-uno', pinName: '21' },
         end: { componentId: 'e32-oled1', pinName: 'DATA' },
         color: '#22aaff',
       },
       {
         id: 'e32o-scl',
-        start: { componentId: 'esp32', pinName: '22' },
+        start: { componentId: 'arduino-uno', pinName: '22' },
         end: { componentId: 'e32-oled1', pinName: 'CLK' },
         color: '#ff8800',
       },
@@ -7537,50 +7537,50 @@ void loop() {
       // SPI bus
       {
         id: 'cam-w-mosi',
-        start: { componentId: 'esp32-cam', pinName: '13' },
+        start: { componentId: 'arduino-uno', pinName: '13' },
         end: { componentId: 'tft1', pinName: 'MOSI' },
         color: '#3498db',
       },
       {
         id: 'cam-w-sck',
-        start: { componentId: 'esp32-cam', pinName: '12' },
+        start: { componentId: 'arduino-uno', pinName: '12' },
         end: { componentId: 'tft1', pinName: 'SCK' },
         color: '#27ae60',
       },
       {
         id: 'cam-w-cs',
-        start: { componentId: 'esp32-cam', pinName: '15' },
+        start: { componentId: 'arduino-uno', pinName: '15' },
         end: { componentId: 'tft1', pinName: 'CS' },
         color: '#e67e22',
       },
       {
         id: 'cam-w-dc',
-        start: { componentId: 'esp32-cam', pinName: '14' },
+        start: { componentId: 'arduino-uno', pinName: '14' },
         end: { componentId: 'tft1', pinName: 'D/C' },
         color: '#f1c40f',
       },
       {
         id: 'cam-w-rst',
-        start: { componentId: 'esp32-cam', pinName: '2' },
+        start: { componentId: 'arduino-uno', pinName: '2' },
         end: { componentId: 'tft1', pinName: 'RST' },
         color: '#ecf0f1',
       },
       // Power
       {
         id: 'cam-w-vcc',
-        start: { componentId: 'esp32-cam', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'tft1', pinName: 'VCC' },
         color: '#e74c3c',
       },
       {
         id: 'cam-w-led',
-        start: { componentId: 'esp32-cam', pinName: '3V3' },
+        start: { componentId: 'arduino-uno', pinName: '3V3' },
         end: { componentId: 'tft1', pinName: 'LED' },
         color: '#e74c3c',
       },
       {
         id: 'cam-w-gnd',
-        start: { componentId: 'esp32-cam', pinName: 'GND.2' },
+        start: { componentId: 'arduino-uno', pinName: 'GND.2' },
         end: { componentId: 'tft1', pinName: 'GND' },
         color: '#2c3e50',
       },
diff --git a/frontend/src/simulation/AVRSimulator.ts b/frontend/src/simulation/AVRSimulator.ts
index 2dca3252..d846a481 100644
--- a/frontend/src/simulation/AVRSimulator.ts
+++ b/frontend/src/simulation/AVRSimulator.ts
@@ -427,6 +427,14 @@ export class AVRSimulator {
     if (!this.cpu) return;
     console.log('Setting up pin hooks...');
 
+    // DDR register addresses (used to distinguish OUTPUT pins from
+    // INPUT_PULLUP — see PinManager.updatePort ddrMask param).
+    //   ATmega328P/Uno/Nano: DDRB=0x24, DDRC=0x27, DDRD=0x2A
+    //   ATtiny85:            DDRB=0x37
+    //   ATmega2560: per-port table below
+    const cpu = this.cpu;
+    const readDdr = (addr: number) => cpu.data[addr] ?? 0;
+
     if (this.boardVariant === 'tiny85') {
       // ATtiny85: PORTB only, PB0-PB5 → pins 0-5
       // Must pass an explicit pinMap so updatePort uses offset 0 instead of the
@@ -434,20 +442,26 @@ export class AVRSimulator {
       const TINY85_PIN_MAP = [0, 1, 2, 3, 4, 5, -1, -1];
       this.portB!.addListener((value) => {
         if (value !== this.lastPortBValue) {
-          this.pinManager.updatePort('PORTB', value, this.lastPortBValue, TINY85_PIN_MAP);
+          this.pinManager.updatePort('PORTB', value, this.lastPortBValue, TINY85_PIN_MAP, readDdr(0x37));
           this.firePinChangeWithTime(value, this.lastPortBValue, null, 0);
           this.lastPortBValue = value;
         }
       });
     } else if (this.boardVariant === 'mega') {
       // Mega: use explicit per-bit pin maps for all 11 ports
+      const MEGA_DDR_ADDRS: Record<string, number> = {
+        PORTA: 0x21, PORTB: 0x24, PORTC: 0x27, PORTD: 0x2A,
+        PORTE: 0x2D, PORTF: 0x30, PORTG: 0x33, PORTH: 0x101,
+        PORTJ: 0x104, PORTK: 0x107, PORTL: 0x10A,
+      };
       for (const [portName, port] of this.megaPorts) {
         const pinMap = MEGA_PORT_BIT_MAP[portName];
+        const ddrAddr = MEGA_DDR_ADDRS[portName];
         this.megaPortValues.set(portName, 0);
         port.addListener((value) => {
           const old = this.megaPortValues.get(portName) ?? 0;
           if (value !== old) {
-            this.pinManager.updatePort(portName, value, old, pinMap);
+            this.pinManager.updatePort(portName, value, old, pinMap, ddrAddr ? readDdr(ddrAddr) : undefined);
             this.firePinChangeWithTime(value, old, pinMap);
             this.megaPortValues.set(portName, value);
           }
@@ -457,21 +471,21 @@ export class AVRSimulator {
       // Uno / Nano: simple 3-port setup
       this.portB!.addListener((value) => {
         if (value !== this.lastPortBValue) {
-          this.pinManager.updatePort('PORTB', value, this.lastPortBValue);
+          this.pinManager.updatePort('PORTB', value, this.lastPortBValue, undefined, readDdr(0x24));
           this.firePinChangeWithTime(value, this.lastPortBValue, null, 8);
           this.lastPortBValue = value;
         }
       });
       this.portC!.addListener((value) => {
         if (value !== this.lastPortCValue) {
-          this.pinManager.updatePort('PORTC', value, this.lastPortCValue);
+          this.pinManager.updatePort('PORTC', value, this.lastPortCValue, undefined, readDdr(0x27));
           this.firePinChangeWithTime(value, this.lastPortCValue, null, 14);
           this.lastPortCValue = value;
         }
       });
       this.portD!.addListener((value) => {
         if (value !== this.lastPortDValue) {
-          this.pinManager.updatePort('PORTD', value, this.lastPortDValue);
+          this.pinManager.updatePort('PORTD', value, this.lastPortDValue, undefined, readDdr(0x2A));
           this.firePinChangeWithTime(value, this.lastPortDValue, null, 0);
           this.lastPortDValue = value;
         }
diff --git a/frontend/src/simulation/Esp32C3Simulator.ts b/frontend/src/simulation/Esp32C3Simulator.ts
index baf9fc76..be0347e1 100644
--- a/frontend/src/simulation/Esp32C3Simulator.ts
+++ b/frontend/src/simulation/Esp32C3Simulator.ts
@@ -298,7 +298,7 @@ export class Esp32C3Simulator {
                 `[ESP32-C3] GPIO${bit} → ${state ? 'HIGH' : 'LOW'} @ ${timeMs.toFixed(1)}ms`,
               );
               this.onPinChangeWithTime?.(bit, state, timeMs);
-              this.pinManager.setPinState(bit, state);
+              this.pinManager.setPinState(bit, state, 'mcu');
             }
           }
         }
diff --git a/frontend/src/simulation/PinManager.ts b/frontend/src/simulation/PinManager.ts
index 19fa2596..4551c26a 100644
--- a/frontend/src/simulation/PinManager.ts
+++ b/frontend/src/simulation/PinManager.ts
@@ -27,6 +27,12 @@ export class PinManager {
   private analogListeners: Map<number, Set<AnalogCallback>> = new Map();
   private pinStates: Map<number, boolean> = new Map();
   private pwmValues: Map<number, number> = new Map();
+  // Pins the MCU has driven (digitalWrite / PWM / port-listener fire).
+  // Consumed by collectPinStates.ts to emit a SPICE V-source only for
+  // real outputs — leaving INPUT pins floating so external sensors
+  // (NTC + divider on A0, photoresistor, etc.) don't get clamped to
+  // the MCU's idle V-source.
+  private outputPins: Set<number> = new Set();
 
   // ── Digital pin API ──────────────────────────────────────────────────────
 
@@ -54,8 +60,21 @@ export class PinManager {
    *                  Use -1 for bits that are not exposed as Arduino pins.
    *                  When omitted the legacy Uno/Nano fixed offsets are used:
    *                  PORTB→8, PORTC→14, PORTD→0.
+   * @param ddrMask   Optional DDR register value (8 bits). When provided,
+   *                  a pin is added to `outputPins` only if its DDR bit is
+   *                  1 (the AVR is actively driving it as OUTPUT). Without
+   *                  this guard, the PORTx write that activates INPUT_PULLUP
+   *                  (DDR=0, PORT=1) falsely marks the pin as MCU output
+   *                  and emits an ideal V-source on the SPICE side, fighting
+   *                  the real external circuit (button, sensor, pull-down).
    */
-  updatePort(portName: string, newValue: number, oldValue: number = 0, pinMap?: number[]) {
+  updatePort(
+    portName: string,
+    newValue: number,
+    oldValue: number = 0,
+    pinMap?: number[],
+    ddrMask?: number,
+  ) {
     const legacyOffsets: Record<string, number> = { PORTB: 8, PORTC: 14, PORTD: 0 };
 
     for (let bit = 0; bit < 8; bit++) {
@@ -68,6 +87,10 @@ export class PinManager {
         if (arduinoPin < 0) continue; // unmapped bit
 
         this.pinStates.set(arduinoPin, newState);
+        // Only mark as MCU-output if DDR bit is set (or DDR unknown → legacy).
+        if (ddrMask === undefined || (ddrMask & mask) !== 0) {
+          this.outputPins.add(arduinoPin);
+        }
 
         const callbacks = this.listeners.get(arduinoPin);
         if (callbacks) {
@@ -84,32 +107,47 @@ export class PinManager {
   /**
    * Set a single pin state and notify listeners.
    * Alias for triggerPinChange — used by ESP32-C3, RISC-V, and RP2040 simulators.
+   *
+   * `source` distinguishes MCU GPIO writes (mark pin as output for SPICE)
+   * from external actors like buttons or sensor parts (don't mark).
    */
-  setPinState(pin: number, state: boolean): void {
-    this.triggerPinChange(pin, state);
+  setPinState(pin: number, state: boolean, source: 'mcu' | 'external' = 'external'): void {
+    this.triggerPinChange(pin, state, source);
   }
 
   /**
    * Directly fire pin change callbacks for a specific pin.
    * Used by RP2040Simulator which has individual GPIO listeners instead of PORT registers.
    */
-  triggerPinChange(pin: number, state: boolean): void {
+  triggerPinChange(pin: number, state: boolean, source: 'mcu' | 'external' = 'external'): void {
     const current = this.pinStates.get(pin);
-    if (current === state) return; // no change
+    if (current === state) {
+      if (source === 'mcu') this.outputPins.add(pin);
+      return;
+    }
     this.pinStates.set(pin, state);
+    if (source === 'mcu') this.outputPins.add(pin);
     const callbacks = this.listeners.get(pin);
     if (callbacks) {
       callbacks.forEach((cb) => cb(pin, state));
     }
   }
 
+  /** Pins the MCU has actively driven this session. */
+  getOutputPins(): ReadonlySet<number> {
+    return this.outputPins;
+  }
+
   /**
-   * Clear cached pin states (without removing listeners).
-   * Useful in tests so that a fresh `triggerPinChange` after a reset
-   * isn't suppressed by the same-state early-return.
+   * Clear cached pin states + output-pin classifications.  Called by
+   * stopBoard / resetBoard so the next Run starts without stale output
+   * classifications from a previous session forcing premature V-source
+   * emission.  Also keeps the test fixtures' fresh-triggerPinChange path
+   * (the original reason this helper exists) working.
    */
   resetPinStates(): void {
     this.pinStates.clear();
+    this.outputPins.clear();
   }
 
   // ── PWM duty cycle API ───────────────────────────────────────────────────
@@ -133,6 +171,7 @@ export class PinManager {
    */
   updatePwm(pin: number, dutyCycle: number): void {
     this.pwmValues.set(pin, dutyCycle);
+    if (dutyCycle > 0) this.outputPins.add(pin);
     const callbacks = this.pwmListeners.get(pin);
     if (callbacks) {
       callbacks.forEach((cb) => cb(pin, dutyCycle));
@@ -209,5 +248,6 @@ export class PinManager {
     this.listeners.clear();
     this.pwmListeners.clear();
     this.analogListeners.clear();
+    this.outputPins.clear();
   }
 }
diff --git a/frontend/src/simulation/RP2040Simulator.ts b/frontend/src/simulation/RP2040Simulator.ts
index 04adf228..cf8d5bff 100644
--- a/frontend/src/simulation/RP2040Simulator.ts
+++ b/frontend/src/simulation/RP2040Simulator.ts
@@ -513,7 +513,7 @@ export class RP2040Simulator {
 
       const unsub = gpio.addListener((state: GPIOPinState) => {
         const isHigh = state === GPIOPinState.High || state === GPIOPinState.InputPullUp;
-        this.pinManager.triggerPinChange(pin, isHigh);
+        this.pinManager.triggerPinChange(pin, isHigh, 'mcu');
         if (this.onPinChangeWithTime && this.rp2040) {
           // IClock interface exposes `nanos` (not `timeUs`)
           // eslint-disable-next-line @typescript-eslint/no-explicit-any
diff --git a/frontend/src/simulation/RiscVSimulator.ts b/frontend/src/simulation/RiscVSimulator.ts
index 07060ea4..eac70909 100644
--- a/frontend/src/simulation/RiscVSimulator.ts
+++ b/frontend/src/simulation/RiscVSimulator.ts
@@ -139,7 +139,7 @@ export class RiscVSimulator {
                 const pin = pinOffset + bit;
                 const state = !!(val & (1 << bit));
                 this.onPinChangeWithTime?.(pin, state, timeMs);
-                this.pinManager.setPinState(pin, state);
+                this.pinManager.setPinState(pin, state, 'mcu');
               }
             }
           }
diff --git a/frontend/src/simulation/parts/BasicParts.ts b/frontend/src/simulation/parts/BasicParts.ts
index ebfc8137..570603c5 100644
--- a/frontend/src/simulation/parts/BasicParts.ts
+++ b/frontend/src/simulation/parts/BasicParts.ts
@@ -13,6 +13,13 @@ PartSimulationRegistry.register('pushbutton', {
       getArduinoPinHelper('1.r') ??
       getArduinoPinHelper('2.r');
 
+    // Seed the input pin HIGH so `digitalRead()` returns HIGH while the
+    // button is idle.  avr8js does not auto-simulate INPUT_PULLUP — without
+    // this, the firmware reads LOW from the moment loop() starts and
+    // believes the button is permanently pressed (the classic "LED is
+    // always on, pressing the button does nothing" UX bug).
+    if (arduinoPin !== null) avrSimulator.setPinState(arduinoPin, true);
+
     const onButtonPress = () => {
       if (arduinoPin !== null) avrSimulator.setPinState(arduinoPin, false); // Active LOW
       (element as any).pressed = true;
@@ -44,6 +51,10 @@ PartSimulationRegistry.register('pushbutton-6mm', {
       getArduinoPinHelper('1.r') ??
       getArduinoPinHelper('2.r');
 
+    // Same INPUT_PULLUP seeding as the full-size pushbutton — see comment
+    // in `register('pushbutton', ...)` above for why this is required.
+    if (arduinoPin !== null) avrSimulator.setPinState(arduinoPin, true);
+
     const onPress = () => {
       if (arduinoPin !== null) avrSimulator.setPinState(arduinoPin, false);
       (element as any).pressed = true;
diff --git a/frontend/src/simulation/spice/CircuitSimulationService.ts b/frontend/src/simulation/spice/CircuitSimulationService.ts
index 5538bd57..10dea897 100644
--- a/frontend/src/simulation/spice/CircuitSimulationService.ts
+++ b/frontend/src/simulation/spice/CircuitSimulationService.ts
@@ -26,7 +26,7 @@
  *   - No SPICE-engine knowledge — that's in the adapters.
  */
 import { buildInputFromStore } from './storeAdapter';
-import { buildNetlist } from './NetlistBuilder';
+import { buildNetlist, sanitizeSpiceId } from './NetlistBuilder';
 import type { TimeWaveforms } from './types';
 
 /** What the service needs from the simulator store. */
@@ -106,8 +106,15 @@ export interface ServiceOptions {
 export class CircuitSimulationService {
   private inFlight = false;
   private pending = false;
-  private pendingMcuEdge: { boardId: string; pinName: string; state: boolean; vcc: number } | null =
-    null;
+  // Per-pin pending edge buffer. Keyed by `${boardId}|${pinName}`. A single
+  // slot would be overwritten when several pins toggle during the same
+  // in-flight tick (Traffic Light: red→yellow→green hand off within ~µs of
+  // each other) — the LATEST edge would win, dropping the rest. With a Map
+  // every pin's most-recent edge is preserved and replayed after the tick.
+  private pendingMcuEdges = new Map<
+    string,
+    { boardId: string; pinName: string; state: boolean; vcc: number }
+  >();
 
   /**
    * Last loaded circuit context — used by `handleMcuEdge` to extract
@@ -145,10 +152,12 @@ export class CircuitSimulationService {
       if (this.pending) {
         this.pending = false;
         void this.tick();
-      } else if (this.pendingMcuEdge) {
-        const edge = this.pendingMcuEdge;
-        this.pendingMcuEdge = null;
-        void this.handleMcuEdge(edge.boardId, edge.pinName, edge.state, edge.vcc);
+      } else if (this.pendingMcuEdges.size > 0) {
+        const edges = Array.from(this.pendingMcuEdges.values());
+        this.pendingMcuEdges.clear();
+        for (const edge of edges) {
+          void this.handleMcuEdge(edge.boardId, edge.pinName, edge.state, edge.vcc);
+        }
       }
     }
   }
@@ -160,13 +169,15 @@ export class CircuitSimulationService {
    * voltages to useElectricalStore.
    *
    * Coalesces with the canvas-change tick: if a full solve is in
-   * flight, the edge is queued and replayed after that solve
-   * completes (so the netlist is fresh).  Last-edge-wins per pin
-   * since edges overwrite the same field.
+   * flight, the edge is queued per-pin (Map keyed by `boardId|pinName`)
+   * and replayed after the tick completes — last-state-wins PER pin,
+   * so different pins toggling during the same tick don't drop each
+   * other's edges.
    */
   async handleMcuEdge(boardId: string, pinName: string, state: boolean, vcc: number): Promise<void> {
+    const pinKey = `${boardId}|${pinName}`;
     if (this.inFlight) {
-      this.pendingMcuEdge = { boardId, pinName, state, vcc };
+      this.pendingMcuEdges.set(pinKey, { boardId, pinName, state, vcc });
       return;
     }
     if (!this.loadedContext) {
@@ -175,6 +186,20 @@ export class CircuitSimulationService {
       void this.tick();
       return;
     }
+    // Self-heal: if this is the FIRST edge on a pin that wasn't classified
+    // as MCU-output when the netlist was built, the matching V-source
+    // doesn't exist — alterSource would be a silent no-op.  Trigger a
+    // full rebuild instead; collectPinStates now sees the pin in
+    // outputPins and emits the V-source, so the next edge alters normally.
+    const expected = `v_${sanitizeSpiceId(boardId)}_${sanitizeSpiceId(pinName)}`.toLowerCase();
+    const hasSource = this.loadedContext.voltageSources.some(
+      (vs) => vs.toLowerCase() === expected,
+    );
+    if (!hasSource) {
+      this.pendingMcuEdges.set(pinKey, { boardId, pinName, state, vcc });
+      void this.tick();
+      return;
+    }
     this.inFlight = true;
     try {
       // alter + resolveDc internally; the scheduler's
@@ -189,6 +214,12 @@ export class CircuitSimulationService {
       if (this.pending) {
         this.pending = false;
         void this.tick();
+      } else if (this.pendingMcuEdges.size > 0) {
+        const edges = Array.from(this.pendingMcuEdges.values());
+        this.pendingMcuEdges.clear();
+        for (const edge of edges) {
+          void this.handleMcuEdge(edge.boardId, edge.pinName, edge.state, edge.vcc);
+        }
       }
     }
   }
diff --git a/frontend/src/simulation/spice/MixedModeScheduler.ts b/frontend/src/simulation/spice/MixedModeScheduler.ts
index 86a64ad0..0c0628e4 100644
--- a/frontend/src/simulation/spice/MixedModeScheduler.ts
+++ b/frontend/src/simulation/spice/MixedModeScheduler.ts
@@ -37,6 +37,7 @@
 
 import type { SolverPort, SolveAnalysis } from './ports/SolverPort';
 import { NgSpiceWorkerAdapter } from './adapters/NgSpiceWorkerAdapter';
+import { sanitizeSpiceId } from './NetlistBuilder';
 import type { PinState, SpiceVoltageSource } from '../PinResolver';
 
 /**
@@ -249,7 +250,10 @@ class MixedModeSchedulerImpl implements SpiceVoltageSource {
     vcc: number,
   ): Promise<void> {
     if (!this.solver) return;
-    const sourceName = `V_${boardId}_${pinName}`;
+    // Must match the sanitized name NetlistBuilder emits — see comment
+    // at the V-source emission site for why ngspice's `alter` command
+    // can't accept hyphens.
+    const sourceName = `V_${sanitizeSpiceId(boardId)}_${sanitizeSpiceId(pinName)}`;
     const voltage = state ? vcc : 0;
     await this.solver.alterSource(sourceName, voltage);
     await this.resolveDc();
diff --git a/frontend/src/simulation/spice/NetlistBuilder.ts b/frontend/src/simulation/spice/NetlistBuilder.ts
index ccbb0919..a040de18 100644
--- a/frontend/src/simulation/spice/NetlistBuilder.ts
+++ b/frontend/src/simulation/spice/NetlistBuilder.ts
@@ -30,6 +30,21 @@ function skipCanonicalization(metadataId: string): boolean {
   return metadataId.startsWith('instr-');
 }
 
+/**
+ * Sanitize a component / board / pin id for use inside a SPICE identifier
+ * (V-source name, etc.). ngspice's interactive `alter` command treats `-`
+ * as an arithmetic / range operator and silently no-ops on hyphenated
+ * source names — so even though the netlist *parser* tolerates hyphens
+ * via the regex on line 206, mid-simulation MCU pin transitions stop
+ * propagating after the first solve. Substituting `-` → `_` here keeps
+ * the identifier ngspice-safe AND consistent with whatever the scheduler
+ * passes to `alter`. Must be reused by MixedModeScheduler when building
+ * the alter target name.
+ */
+export function sanitizeSpiceId(id: string): string {
+  return id.replace(/-/g, '_');
+}
+
 export interface BuildNetlistResult {
   netlist: string;
   /** "boardId:pinName" → SPICE net name, from the same UF used to build the netlist. */
@@ -81,6 +96,18 @@ export function buildNetlist(input: BuildNetlistInput): BuildNetlistResult {
     for (const pinName of board.vccPinNames ?? []) {
       uf.setCanonical(pinKey(board.id, pinName), 'vcc_rail');
     }
+    // Fallback: any board pin a wire references whose name looks like a
+    // ground pin (GND, GND.1, GND.9, etc.) is canonicalized to "0" even if
+    // it's not in `groundPinNames`. Boards with many GND pins (ESP32-C3
+    // dev kits ship up to 10) often miss some in the per-board list, which
+    // would leave wires connected to those pins floating instead of grounded.
+    for (const pinName of pinsReferencedByWires(board.id, wires)) {
+      if (GROUND_PIN_RE.test(pinName)) {
+        uf.setCanonical(pinKey(board.id, pinName), '0');
+      } else if (VCC_PIN_RE.test(pinName)) {
+        uf.setCanonical(pinKey(board.id, pinName), 'vcc_rail');
+      }
+    }
   }
   for (const comp of components) {
     if (skipCanonicalization(comp.metadataId)) continue;
@@ -117,6 +144,14 @@ export function buildNetlist(input: BuildNetlistInput): BuildNetlistResult {
   }
 
   // ── 5. Board GPIO sources ─────────────────────────────────────────────────
+  // Hyphens are kept in the V-source name (NetlistBuilder regex on line 206
+  // captures `[_\w-]*`), so ngspice itself can parse + load the source and
+  // expose the branch current as `v_<board>-<pin>#branch` — visible in the
+  // canvas voltmeters / branch-current map. BUT ngspice's *interactive*
+  // `alter` command treats `-` as an operator and silently no-ops on
+  // hyphenated source names — making MCU pin transitions stop propagating
+  // after the very first solve. So MixedModeScheduler.onMcuPinChange must
+  // build the same sanitized name we emit here. See sanitizeSpiceId().
   for (const board of boards) {
     for (const [pinName, state] of Object.entries(board.pins)) {
       if (state.type === 'input') continue; // don't drive the pin
@@ -124,7 +159,7 @@ export function buildNetlist(input: BuildNetlistInput): BuildNetlistResult {
       if (!net) continue;
       if (net === '0' || net === 'vcc_rail') continue; // already served
       const v = state.type === 'digital' ? state.v : state.duty * board.vcc;
-      cards.push(`V_${board.id}_${pinName} ${net} 0 DC ${v}`);
+      cards.push(`V_${sanitizeSpiceId(board.id)}_${sanitizeSpiceId(pinName)} ${net} 0 DC ${v}`);
     }
   }
 
diff --git a/frontend/src/simulation/spice/collectPinStates.ts b/frontend/src/simulation/spice/collectPinStates.ts
index 4a06ceb0..fc8ccf2c 100644
--- a/frontend/src/simulation/spice/collectPinStates.ts
+++ b/frontend/src/simulation/spice/collectPinStates.ts
@@ -66,32 +66,32 @@ export function collectPinStates(
     if (w.end.componentId === boardId) pinNames.add(w.end.pinName);
   }
 
+  const outputPins = pm.getOutputPins();
+
   for (const pinName of pinNames) {
     const arduinoPin = pinNameToArduinoPin(pinName, boardKind);
     if (arduinoPin < 0) continue;
     const pwmDuty = pm.getPwmValue(arduinoPin);
     if (pwmDuty > 0) {
       result[pinName] = { type: 'pwm', duty: pwmDuty };
-    } else {
-      // ALWAYS emit a digital source — even when the pin is currently
-      // LOW. NetlistBuilder turns this into a `V_<board>_<pin>` card,
-      // and MixedModeScheduler.onMcuPinChange later calls
-      // `alterSource('V_<board>_<pin>', vcc | 0)` on every MCU edge.
-      // If the V-source isn't in the netlist (because we skipped it
-      // here while LOW), the alter is a silent no-op against a name
-      // that doesn't exist; the LED then never lights up no matter
-      // how many times the sketch toggles the pin afterwards.
-      //
-      // This was the root cause of the reported "sometimes the LED
-      // works after Run, sometimes it doesn't" symptom. The behaviour
-      // was deterministic but appeared random because it depended on
-      // whether the AVR happened to be in the HIGH half of its blink
-      // cycle at the moment runSolve() captured pin states.
+      continue;
+    }
+    if (outputPins.has(arduinoPin)) {
+      // The MCU has actually driven this pin at least once
+      // (digitalWrite / PWM / port-listener fire), so emit a V-source
+      // for NetlistBuilder.  MixedModeScheduler.onMcuPinChange will
+      // alterSource() on each subsequent edge; the V-source needs to
+      // exist in the netlist for the alter to bind (otherwise it's a
+      // silent no-op and the LED never updates).
       result[pinName] = {
         type: 'digital',
         v: pm.getPinState(arduinoPin) ? vcc : 0,
       };
     }
+    // else: leave the net free — external components (sensor divider,
+    // pull-up, button, etc.) drive the SPICE node.  Without this guard,
+    // an unconditional V-source at 0 V would short-circuit any analog
+    // sensor on the pin and analogRead() would always return 0.
   }
   return result;
 }
diff --git a/frontend/src/simulation/spice/connectMcuEdgesToService.ts b/frontend/src/simulation/spice/connectMcuEdgesToService.ts
index ac7bbbfb..035b861a 100644
--- a/frontend/src/simulation/spice/connectMcuEdgesToService.ts
+++ b/frontend/src/simulation/spice/connectMcuEdgesToService.ts
@@ -128,9 +128,35 @@ export function connectMcuEdgesToService(service: CircuitSimulationService): ()
       if (!pinName) continue;
       if (wanted.size > 0 && !wanted.has(pinName)) continue;
       const unsub = pm.onPinChange(pin, (_p, state) => {
+        // Suppress digital edges when the pin has active PWM. The OCR-based
+        // PWM duty is converted to a DC-averaged voltage in NetlistBuilder
+        // (`state.duty * board.vcc`), giving smooth analog dimming. If we
+        // also let the Timer1/Timer2-driven port toggles fire alterSource,
+        // each PWM cycle's HIGH/LOW transition would race with the duty
+        // average and force the V-source to bounce between 0 and vcc —
+        // making `analogWrite(pin, 128)` look like a binary blink instead
+        // of a steady 2.5 V (Fade-LED example regression).
+        if (pm.getPwmValue(pin) > 0) return;
         schedulePin(boardId, pinName, state, vcc);
       });
       pinSubs.set(pin, unsub);
+
+      // Re-tick when PWM duty changes so the duty-averaged V-source picks
+      // up new analogWrite values. Without this, duty stays whatever it was
+      // at first solve and `analogWrite()` in a loop never updates the
+      // visible LED. Throttled to ~60 Hz to amortise the netlist-rebuild
+      // cost (the firmware ramps brightness every 30 ms in the canonical
+      // Fade-LED example, well within this budget).
+      let pwmTickPending = false;
+      const unsubPwm = pm.onPwmChange(pin, () => {
+        if (pwmTickPending) return;
+        pwmTickPending = true;
+        setTimeout(() => {
+          pwmTickPending = false;
+          void service.tick();
+        }, 16);
+      });
+      pinSubs.set(pin + 1000, unsubPwm); // key offset to avoid collision
     }
   }
 
diff --git a/frontend/src/simulation/spice/start.ts b/frontend/src/simulation/spice/start.ts
index b9104136..3768386e 100644
--- a/frontend/src/simulation/spice/start.ts
+++ b/frontend/src/simulation/spice/start.ts
@@ -17,7 +17,7 @@
  *
  * Phase 1c step G1 of the mixed-mode migration.
  */
-import { useSimulatorStore } from '../../store/useSimulatorStore';
+import { useSimulatorStore, getBoardPinManager } from '../../store/useSimulatorStore';
 import { useElectricalStore } from '../../store/useElectricalStore';
 import {
   getMixedModeScheduler,
@@ -86,22 +86,41 @@ export function startSimulation(): () => void {
   // to get a snapshot of the simulation state (analysis mode, voltage
   // count, pin map, last solve time, etc.).  Useful for diagnosing
   // "why is my circuit not solving?" reports from users.
-  (window as unknown as { __spiceDebug?: () => void }).__spiceDebug = () => {
+  (window as unknown as { __spiceDebug?: () => unknown }).__spiceDebug = () => {
     const electrical = useElectricalStore.getState();
-    // eslint-disable-next-line no-console
-    console.log('[__spiceDebug]', {
+    // Probe: collect every board's outputPins set so we can verify the
+    // MCU-direction-tracking fix from the harness.
+    const outputPinsByBoard: Record<string, number[]> = {};
+    try {
+      const boards = useSimulatorStore.getState().boards;
+      for (const b of boards) {
+        const pm = getBoardPinManager(b.id);
+        if (pm && typeof pm.getOutputPins === 'function') {
+          outputPinsByBoard[b.id] = [...pm.getOutputPins()];
+        }
+      }
+    } catch {
+      // ignore — fallback already covered by snapshot fields below
+    }
+    const snapshot = {
       analysisMode: electrical.analysisMode,
       converged: electrical.converged,
       error: electrical.error,
       lastSolveMs: electrical.lastSolveMs,
       nodeVoltageCount: Object.keys(electrical.nodeVoltages).length,
       branchCurrentCount: Object.keys(electrical.branchCurrents).length,
+      branchCurrentNames: Object.keys(electrical.branchCurrents),
       pinNetMapSize: electrical.pinNetMap.size,
+      pinNetMapEntries: [...electrical.pinNetMap.entries()],
+      nodeVoltages: { ...electrical.nodeVoltages },
       hasTimeWaveforms: !!electrical.timeWaveforms,
       paused: electrical.paused,
-      sampleVoltages: Object.entries(electrical.nodeVoltages).slice(0, 8),
-      pinNetSample: [...electrical.pinNetMap.entries()].slice(0, 8),
-    });
+      outputPinsByBoard,
+    };
+    (window as unknown as { __lastSpice?: unknown }).__lastSpice = snapshot;
+    // eslint-disable-next-line no-console
+    console.log('[__spiceDebug]', snapshot);
+    return snapshot;
   };
 
   return () => {
diff --git a/frontend/src/store/useSimulatorStore.ts b/frontend/src/store/useSimulatorStore.ts
index 81a07431..05221a15 100644
--- a/frontend/src/store/useSimulatorStore.ts
+++ b/frontend/src/store/useSimulatorStore.ts
@@ -969,7 +969,7 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
         bridge.onSerialData = serialCallback;
         bridge.onPinChange = (gpioPin, state) => {
           const boardPm = pinManagerMap.get(id);
-          if (boardPm) boardPm.triggerPinChange(gpioPin, state);
+          if (boardPm) boardPm.triggerPinChange(gpioPin, state, 'mcu');
         };
         bridge.onCrash = () => {
           set({ esp32CrashBoardId: id });
@@ -1157,19 +1157,6 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
             ),
           }));
         }
-        if (b.boardOptions || b.spiffsFiles) {
-          set((s) => ({
-            boards: s.boards.map((bb) =>
-              bb.id === b.id
-                ? {
-                    ...bb,
-                    boardOptions: b.boardOptions,
-                    spiffsFiles: b.spiffsFiles,
-                  }
-                : bb,
-            ),
-          }));
-        }
       });
 
       // Replace editor file groups atomically. Skip groups that already exist
@@ -1549,6 +1536,11 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
         getBoardSimulator(boardId)?.stop();
       }
 
+      // Drop MCU-output classification so the next Run starts clean and
+      // collectPinStates doesn't emit stale V-sources before the new
+      // firmware has driven any pins.
+      getBoardPinManager(boardId)?.resetPinStates();
+
       set((s) => {
         const boards = s.boards.map((b) => (b.id === boardId ? { ...b, running: false } : b));
         const isActive = s.activeBoardId === boardId;
@@ -1571,6 +1563,9 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
         const sim = getBoardSimulator(boardId);
         if (sim) {
           sim.reset();
+          // Drop MCU-output classification so the new program starts
+          // clean — no stale V-sources from the previous run.
+          getBoardPinManager(boardId)?.resetPinStates();
           // Re-wire serial callback after reset
           sim.onSerialData = (ch) => appendSerial(boardId, ch);
           if (sim instanceof AVRSimulator) {
@@ -1637,7 +1632,7 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
         bridge.onSerialData = serialCallback;
         bridge.onPinChange = (gpioPin, state) => {
           const boardPm = pinManagerMap.get(boardId);
-          if (boardPm) boardPm.triggerPinChange(gpioPin, state);
+          if (boardPm) boardPm.triggerPinChange(gpioPin, state, 'mcu');
         };
         bridge.onCrash = () => {
           set({ esp32CrashBoardId: boardId });
@@ -1739,7 +1734,7 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
         bridge.onSerialData = serialCallback;
         bridge.onPinChange = (gpioPin, state) => {
           const boardPm = pinManagerMap.get(boardId);
-          if (boardPm) boardPm.triggerPinChange(gpioPin, state);
+          if (boardPm) boardPm.triggerPinChange(gpioPin, state, 'mcu');
         };
         bridge.onCrash = () => {
           set({ esp32CrashBoardId: boardId });
diff --git a/frontend/src/types/board.ts b/frontend/src/types/board.ts
index 7705f423..b73163c3 100644
--- a/frontend/src/types/board.ts
+++ b/frontend/src/types/board.ts
@@ -129,5 +129,5 @@ export const BOARD_KIND_FQBN: Record<BoardKind, string | null> = {
   'esp32-c3': 'esp32:esp32:esp32c3',
   'xiao-esp32-c3': 'esp32:esp32:XIAO_ESP32C3',
   'aitewinrobot-esp32c3-supermini': 'esp32:esp32:esp32c3',
-  attiny85: 'ATTinyCore:avr:attinyx5:chip=85,clock=internal16mhz',
+  attiny85: 'ATTinyCore:avr:attinyx5:chip=85,clock=16pll',
 };
diff --git a/scripts/visual-led-test.mjs b/scripts/visual-led-test.mjs
new file mode 100644
index 00000000..7987d8ad
--- /dev/null
+++ b/scripts/visual-led-test.mjs
@@ -0,0 +1,297 @@
+// scripts/visual-led-test.mjs
+//
+// Automated visual LED test — drives the running vite + backend stack via
+// the Chrome DevTools Protocol (CDP). For each named example it:
+//
+//   1. Navigates to /example/<slug>
+//   2. Clicks the Run button (auto-compiles + starts the sim)
+//   3. Waits up to `simulateMs` for the LED brightness to swing
+//   4. Asserts: `wokwi-led.brightness > 0` AT LEAST ONCE (LED lights up)
+//   5. Asserts: `wokwi-led.brightness == 0` AT LEAST ONCE (LED toggles off)
+//      — this catches "stuck on" bugs the snapshot tests miss.
+//
+// Why this matters: unit tests + snapshot tests check static structure
+// (netlist string, SPICE cards). They don't run firmware, don't render
+// LEDs, and don't observe whether `wokwi-led.brightness` ever moves. Every
+// LED-related bug in the recent sprint (INPUT_PULLUP false positive,
+// hyphen-truncated V-source, missing pushbutton init, ESP32-C3 compile
+// failure) shipped past green unit tests and was only caught by manual
+// browser checks. This script makes that check repeatable.
+//
+// Prerequisites:
+//   - Chrome running with `--remote-debugging-port=9222`
+//   - `vite` on http://localhost:5174
+//   - `uvicorn app.main:app --port 8001` with arduino-cli + cores
+//
+// Usage:
+//   node scripts/visual-led-test.mjs               # default suite
+//   node scripts/visual-led-test.mjs blink-led     # single example
+//   FRONTEND=http://localhost:5175 node scripts/visual-led-test.mjs
+//
+// Exits 0 on PASS, 1 on FAIL.
+
+const CDP_HTTP = process.env.CDP_HTTP || 'http://localhost:9222';
+const FRONTEND = process.env.FRONTEND || 'http://localhost:5174';
+
+// Each entry: { slug, label?, simulateMs?, expectToggle?, allowAlwaysOn? }
+//   expectToggle (default true) — require BOTH a lit sample AND a dark
+//     sample. Disable for "permanently on" sketches like sensor read-outs.
+//   allowAlwaysOn — accept "lit but never off" as a pass (still requires lit).
+//   simulateMs — total observation window after Run (default 12000).
+const DEFAULT_SUITE = [
+  { slug: 'blink-led', label: 'Blink (AVR digitalWrite)', simulateMs: 12000 },
+  { slug: 'button-led', label: 'Button + INPUT_PULLUP', simulateMs: 6000,
+    expectInitialOff: true, expectLitAfterRun: false,
+    note: 'LED MUST be off idle AND stay off without button press — catches INPUT_PULLUP false positive' },
+  { slug: 'traffic-light', label: 'Multi-pin sequencing', simulateMs: 14000 },
+  { slug: 'fade-led', label: 'PWM fade gradient', simulateMs: 14000,
+    expectGradient: true,
+    note: 'Brightness must hit 3+ distinct non-zero values (smooth fade)' },
+  { slug: 'rgb-led', label: 'RGB 3-PWM driven', simulateMs: 12000,
+    leafCheck: 'pwmActive' },
+];
+
+// ── CDP plumbing ──────────────────────────────────────────────────────────
+
+async function getPages() {
+  const res = await fetch(`${CDP_HTTP}/json`);
+  return await res.json();
+}
+
+class CDP {
+  constructor(wsUrl) {
+    this.ws = new WebSocket(wsUrl);
+    this.id = 0;
+    this.pending = new Map();
+    this.events = new Map();
+    this.ready = new Promise((resolve, reject) => {
+      this.ws.addEventListener('open', () => resolve(), { once: true });
+      this.ws.addEventListener('error', (e) => reject(e), { once: true });
+    });
+    this.ws.addEventListener('message', (ev) => {
+      const msg = JSON.parse(ev.data.toString());
+      if (msg.id != null) {
+        const p = this.pending.get(msg.id);
+        if (p) {
+          this.pending.delete(msg.id);
+          if (msg.error) p.reject(new Error(msg.error.message));
+          else p.resolve(msg.result);
+        }
+      } else if (msg.method) {
+        const handlers = this.events.get(msg.method);
+        if (handlers) handlers.forEach((h) => h(msg.params));
+      }
+    });
+  }
+  send(method, params = {}) {
+    const id = ++this.id;
+    return new Promise((resolve, reject) => {
+      this.pending.set(id, { resolve, reject });
+      this.ws.send(JSON.stringify({ id, method, params }));
+    });
+  }
+  async eval(expression, { awaitPromise = false } = {}) {
+    const r = await this.send('Runtime.evaluate', {
+      expression, returnByValue: true, awaitPromise,
+    });
+    if (r.exceptionDetails) {
+      throw new Error(
+        r.exceptionDetails.exception?.description ||
+          r.exceptionDetails.text || 'eval failed',
+      );
+    }
+    return r.result?.value;
+  }
+  close() { this.ws.close(); }
+}
+
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+
+// ── Per-example runner ────────────────────────────────────────────────────
+
+async function runOne(cdp, ex) {
+  const simulateMs = ex.simulateMs ?? 12000;
+  await cdp.send('Page.navigate', { url: `${FRONTEND}/example/${ex.slug}` });
+  // Wait for editor + Run button.
+  const waitForEditor = async () => {
+    for (let i = 0; i < 60; i++) {
+      const has = await cdp.eval(`
+        Array.from(document.querySelectorAll('button')).some(b =>
+          /^Run/.test(b.getAttribute('title') || ''))
+      `);
+      if (has) return true;
+      await sleep(250);
+    }
+    return false;
+  };
+  if (!(await waitForEditor())) return { slug: ex.slug, fail: 'editor never loaded' };
+
+  // Optional pre-Run check — for examples like button-led where the LED
+  // MUST be off until interacted with.
+  let preRunBrightness = null;
+  if (ex.expectInitialOff) {
+    // Give SPICE one pass.
+    await sleep(2000);
+    preRunBrightness = await cdp.eval(`
+      (() => {
+        const led = document.querySelector('wokwi-led');
+        return led?.brightness ?? null;
+      })()
+    `);
+  }
+
+  await cdp.eval(`
+    Array.from(document.querySelectorAll('button')).find(b =>
+      /^Run/.test(b.getAttribute('title') || ''))?.click()
+  `);
+
+  // Poll LED brightness every 250 ms for simulateMs.
+  const samples = [];
+  const steps = Math.ceil(simulateMs / 250);
+  for (let i = 0; i < steps; i++) {
+    const reading = await cdp.eval(`
+      (() => {
+        const leds = Array.from(document.querySelectorAll('wokwi-led'));
+        return leds.map(el => ({
+          id: el.id,
+          brightness: el.brightness,
+          value: el.value,
+        }));
+      })()
+    `);
+    samples.push({ t: i * 250, leds: reading });
+    await sleep(250);
+  }
+
+  // ── Assertions ──────────────────────────────────────────────────────────
+  const result = { slug: ex.slug, label: ex.label, preRunBrightness, samples: samples.length };
+
+  if (ex.leafCheck === 'pwmActive') {
+    // No wokwi-led for RGB — check SPICE outputPins via __spiceDebug.
+    const snap = await cdp.eval(`
+      (() => {
+        const s = window.__spiceDebug?.();
+        return s ? { outputPins: s.outputPinsByBoard, branches: s.branchCurrentNames } : null;
+      })()
+    `);
+    const pinCount = snap?.outputPins
+      ? Object.values(snap.outputPins).reduce((n, arr) => n + arr.length, 0) : 0;
+    result.outputPinCount = pinCount;
+    if (pinCount < 3) result.fail = `expected ≥3 pins driven (RGB), got ${pinCount}`;
+    return result;
+  }
+
+  // Standard LED assertions.
+  if (samples[0].leds.length === 0) {
+    // No wokwi-led on canvas — only validate SPICE pin activity.
+    const snap = await cdp.eval(`
+      (() => { const s = window.__spiceDebug?.(); return s ? s.outputPinsByBoard : null; })()
+    `);
+    const pinCount = snap ? Object.values(snap).reduce((n, arr) => n + arr.length, 0) : 0;
+    result.noLed = true;
+    result.outputPinCount = pinCount;
+    if (pinCount === 0) result.fail = 'no LED and no MCU pins driven';
+    return result;
+  }
+
+  const ledId = samples[0].leds[0].id;
+  const bvals = samples.map(s => s.leds.find(l => l.id === ledId)?.brightness ?? 0);
+  const maxB = Math.max(...bvals);
+  const minB = Math.min(...bvals);
+  const distinct = new Set(bvals.map(b => Math.round(b * 100))).size;
+  result.led = ledId;
+  result.maxBrightness = Math.round(maxB * 100) / 100;
+  result.minBrightness = Math.round(minB * 100) / 100;
+  result.distinctLevels = distinct;
+
+  if (ex.expectInitialOff && preRunBrightness != null && preRunBrightness > 0.05) {
+    result.fail = `pre-Run LED brightness ${preRunBrightness.toFixed(2)} — INPUT_PULLUP false positive?`;
+    return result;
+  }
+
+  // expectLitAfterRun:false → button-led style: LED must stay dark without
+  // user interaction. PASS if LED stays under 0.05. FAIL only if it lights
+  // up (which would mean the firmware is misreading the pin).
+  if (ex.expectLitAfterRun === false) {
+    if (maxB > 0.05) {
+      result.fail = `LED lit without user interaction (max=${maxB.toFixed(2)}) — firmware likely reading wrong pin state`;
+    }
+    return result;
+  }
+
+  if (maxB < 0.05) {
+    result.fail = `LED never lit (max brightness ${maxB.toFixed(3)})`;
+    return result;
+  }
+
+  if (ex.expectGradient) {
+    // Smooth fade: require ≥3 distinct brightness buckets across the run.
+    if (distinct < 3) {
+      result.fail = `PWM fade only ${distinct} distinct level(s) — expected smooth gradient (≥3)`;
+      return result;
+    }
+  } else if (ex.expectToggle !== false && !ex.allowAlwaysOn) {
+    // Toggle: require both a lit AND a dark sample.
+    if (minB > 0.05) {
+      result.fail = `LED never went dark (min brightness ${minB.toFixed(3)}) — stuck on?`;
+      return result;
+    }
+  }
+
+  return result;
+}
+
+// ── Driver ────────────────────────────────────────────────────────────────
+
+async function main() {
+  const args = process.argv.slice(2);
+  const suite = args.length
+    ? args.map(slug => DEFAULT_SUITE.find(e => e.slug === slug) ?? { slug })
+    : DEFAULT_SUITE;
+
+  const pages = await getPages();
+  const target = pages.find(p => p.type === 'page' && p.url.startsWith('http'));
+  if (!target) {
+    console.error('[visual-led] No usable Chrome tab. Open one and re-run.');
+    process.exit(2);
+  }
+  const cdp = new CDP(target.webSocketDebuggerUrl);
+  await cdp.ready;
+  await cdp.send('Page.enable');
+  await cdp.send('Runtime.enable');
+
+  let failed = 0;
+  for (const ex of suite) {
+    process.stdout.write(`\n[${ex.slug}] ${ex.label || ''}\n`);
+    try {
+      const r = await runOne(cdp, ex);
+      if (r.fail) {
+        console.log(`  FAIL — ${r.fail}`);
+        console.log(`         ${JSON.stringify({ maxB: r.maxBrightness, minB: r.minBrightness, distinct: r.distinctLevels, pre: r.preRunBrightness })}`);
+        failed++;
+      } else {
+        let detail;
+        if (r.outputPinCount != null && r.maxBrightness == null) {
+          detail = `no canvas LED, ${r.outputPinCount} pin(s) driven`;
+        } else if (r.outputPinCount != null) {
+          detail = `${r.outputPinCount} pin(s) driven, max=${r.maxBrightness} min=${r.minBrightness}`;
+        } else {
+          detail = `max=${r.maxBrightness} min=${r.minBrightness} levels=${r.distinctLevels}`;
+        }
+        console.log(`  PASS — ${detail}`);
+      }
+    } catch (e) {
+      console.log(`  ERROR — ${e.message}`);
+      failed++;
+    }
+  }
+
+  cdp.close();
+  console.log(`\n${suite.length - failed}/${suite.length} examples passed.`);
+  process.exit(failed > 0 ? 1 : 0);
+}
+
+main().catch(err => {
+  console.error('[visual-led] fatal:', err);
+  process.exit(3);
+});