feat(sim): e-ink simulator builds

SIM_EINK=landscape|portrait builds the e-ink firmware for the browser,
drawn by the same EinkGfxDisplay as the panel. index.html and mesh.html
pick a build from the URL. The simulated sensors get a GPS switch, so the
UI's GPS toggle works.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

variants/sim/SimDisplayDriver.h

@@ -462,6 +462,32 @@ public:
   void endFrame() override { }
 };
 
+#ifdef SIM_EINK_PANEL_W
+// An e-ink panel (the Wio Tracker L1 E-ink's 2.13", 122x250 before rotation):
+// EinkGfxDisplay draws, exactly as GxEPDDisplay does on the board, into a 1-bit
+// canvas, and a frame that changed is put on the page in paper and ink. The
+// host page counts refreshes from Module.__einkRefreshes. Bodies in target.cpp,
+// the one TU that pulls in the font tables.
+#include <helpers/ui/EinkGfxDisplay.h>
+#ifndef DISPLAY_ROTATION
+  #define DISPLAY_ROTATION 0
+#endif
+class SimEinkDisplay : public EinkGfxDisplay {
+  bool _on = false;
+  static Adafruit_GFX& canvas();
+public:
+  static const int PANEL_W = SIM_EINK_PANEL_W, PANEL_H = SIM_EINK_PANEL_H;
+  SimEinkDisplay();
+  bool begin();
+  bool isOn() override { return _on; }
+  void turnOn() override { _on = true; }
+  void turnOff() override { _on = false; }
+  void clear() override;
+  void setDisplayRotation(uint8_t rot) override;
+  void endFrame() override;
+};
+#endif
+
 extern "C" EMSCRIPTEN_KEEPALIVE inline void sim_lcd_touch(int x, int y, int down) {
   SimLcdDisplay::Touch& t = SimLcdDisplay::touchState();
   t.x = x; t.y = y; t.down = down != 0;

variants/sim/SimSensorManager.h

@@ -1,4 +1,5 @@
 #pragma once
+#include <string.h>
 
 #include <helpers/SensorManager.h>
 
@@ -35,11 +36,21 @@
 // type turns out to matter for a demo.
 class SimSensorManager : public SensorManager {
   static float& envTemperatureRef() { static float t = 21.0f; return t; }
+  bool _gps = false;   // the "gps" setting, as a real board's GPS switch: the UI's toggle needs it
 
 public:
   LocationProvider* getLocationProvider() override;
   bool querySensors(uint8_t requester_permissions, CayenneLPP& telemetry) override;
 
+  int getNumSettings() const override { return 1; }
+  const char* getSettingName(int i) const override { return i == 0 ? "gps" : NULL; }
+  const char* getSettingValue(int i) const override { return i == 0 ? (_gps ? "1" : "0") : NULL; }
+  bool setSettingValue(const char* name, const char* value) override {
+    if (strcmp(name, "gps") != 0) return false;
+    _gps = strcmp(value, "0") != 0;
+    return true;
+  }
+
   static void setEnvTemperature(float celsius) { envTemperatureRef() = celsius; }
 };
 

variants/sim/build_wasm.sh

@@ -24,6 +24,8 @@
 # Usage:
 #   variants/sim/build_wasm.sh            # release-ish build (-O2)
 #   variants/sim/build_wasm.sh debug       # -O0 -g, easier to debug in devtools
+#   SIM_UI=lvgl variants/sim/build_wasm.sh            # the L2 (web/lvgl.html)
+#   SIM_EINK=landscape variants/sim/build_wasm.sh     # the L1 E-ink, also portrait
 #
 # Requires emsdk 6.0.9 (pinned; see variants/sim/tools/emsdk/ -- installed by
 # this same task, see the Phase 2 report for the exact activation command).
@@ -192,6 +194,28 @@ if [ "$SIM_UI" = "lvgl" ]; then
   LINK_EXTRA=(-sFETCH=1)   # map downloads (LvglPort.h) go through emscripten_fetch
 fi
 
+# SIM_EINK=landscape|portrait: ui-new on the Wio Tracker L1 E-ink's 2.13" panel
+# (122x250, solo/wio-tracker-l1-eink's two builds) instead of the OLED ->
+# web/index.html?build=meshcore_sim_eink_landscape (or _portrait).
+SIM_EINK="${SIM_EINK:-}"
+if [ -n "$SIM_EINK" ]; then
+  case "$SIM_EINK" in
+    landscape) EINK_DEFS=(-DDISPLAY_ROTATION=1 -DEINK_LARGE_FONT=1) ;;
+    portrait)  EINK_DEFS=(-DDISPLAY_ROTATION=0) ;;
+    *) echo "error: SIM_EINK must be landscape or portrait" >&2; exit 1 ;;
+  esac
+  OUT_NAME="meshcore_sim_eink_$SIM_EINK"
+  EXPORT_NAME=MeshCoreSimEink   # distinct factory: web/mesh.html?a=... loads it beside MeshCoreSim
+  kept=()
+  for d in "${DEFINES[@]}"; do
+    case "$d" in -DDISPLAY_CLASS=*|-DMAX_GROUP_CHANNELS=*) ;; *) kept+=("$d") ;; esac
+  done
+  # EINK_DISPLAY_MODEL is only tested for presence outside GxEPDDisplay
+  # (Features.h: the e-ink settings and timings), which the sim doesn't build.
+  DEFINES=("${kept[@]}" -DDISPLAY_CLASS=SimEinkDisplay -DSIM_EINK_PANEL_W=122 -DSIM_EINK_PANEL_H=250
+           -DEINK_DISPLAY_MODEL=SimEinkPanel -DMAX_GROUP_CHANNELS=40 "${EINK_DEFS[@]}")
+fi
+
 # -funsigned-char: carried over from Phase 1 verbatim -- real ARM cores
 # default `char` to unsigned; em++'s target (wasm32) defaults it to signed,
 # same mismatch Phase 1 hit on a native x86/ARM64 host, for the same reason

variants/sim/target.cpp

@@ -157,4 +157,82 @@ void SimDisplayDriverCanvas::print(const char* str) {
   // real y position across embedded '\n's internally.
   _cursor_x += getTextWidth(str);
 }
+
+#ifdef SIM_EINK_PANEL_W
+#include <helpers/ui/EinkGfxDisplayImpl.h>
+
+// The panel's RAM: 1 bit a pixel, ink = 1. GFXcanvas1 rotates like GxEPD2 does.
+Adafruit_GFX& SimEinkDisplay::canvas() {
+  static GFXcanvas1 c(PANEL_W, PANEL_H);
+  return c;
+}
+
+SimEinkDisplay::SimEinkDisplay()
+    : EinkGfxDisplay((DISPLAY_ROTATION & 1) ? PANEL_H : PANEL_W,
+                     (DISPLAY_ROTATION & 1) ? PANEL_W : PANEL_H, canvas(), 1, 0) {
+  canvas().setRotation(DISPLAY_ROTATION);
+}
+
+// Sizes the page's canvas to the panel as it's turned, at Module.simEinkScale
+// (default 3) CSS pixels a pixel.
+static void simEinkFitCanvas(int w, int h) {
+  EM_ASM({
+    var tag = (typeof Module !== 'undefined' && Module['simInstanceTag']) ? Module['simInstanceTag'] : '';
+    var c = document.getElementById(tag ? ('sim-canvas-' + tag) : 'sim-canvas');
+    if (!c) { console.error('[sim] e-ink canvas not found in the host page'); return; }
+    var k = Module.simEinkScale || 3;
+    c.width = $0; c.height = $1;
+    c.style.width = ($0 * k) + 'px'; c.style.height = ($1 * k) + 'px';
+    Module.__simCtx = c.getContext('2d');
+    Module.__simCtx.imageSmoothingEnabled = false;
+    Module.__einkRefreshes = Module.__einkRefreshes || 0;
+  }, w, h);
+}
+
+bool SimEinkDisplay::begin() {
+  _on = true;
+  simEinkFitCanvas(width(), height());
+  return true;
+}
+
+void SimEinkDisplay::clear() {
+  canvas().fillScreen(0);
+  forceRedraw();
+}
+
+void SimEinkDisplay::setDisplayRotation(uint8_t rot) {
+  canvas().setRotation(rot & 3);
+  setDimensions(canvas().width(), canvas().height());
+  updateLayout();
+  simEinkFitCanvas(width(), height());
+}
+
+// Only a frame that differs reaches the page, as only that one costs the
+// board a refresh. Read back through getPixel(), which applies the rotation.
+void SimEinkDisplay::endFrame() {
+  if (!frameChanged()) return;
+  const int w = width(), h = height();
+  static uint8_t px[SIM_EINK_PANEL_W * SIM_EINK_PANEL_H];
+  const GFXcanvas1& c = (const GFXcanvas1&)canvas();
+  for (int y = 0; y < h; y++)
+    for (int x = 0; x < w; x++) px[y * w + x] = c.getPixel(x, y);
+  EM_ASM({
+    if (!Module.__simCtx) return;
+    var w = $1;
+    var h = $2;
+    var img = Module.__simCtx.createImageData(w, h);
+    var d = img.data;
+    for (var i = 0; i < w * h; i++) {
+      var ink = HEAPU8[$0 + i];
+      var o = i * 4;
+      d[o] = ink ? 0x1a : 0xdc;
+      d[o + 1] = ink ? 0x1a : 0xdc;
+      d[o + 2] = ink ? 0x1a : 0xd2;
+      d[o + 3] = 255;
+    }
+    Module.__simCtx.putImageData(img, 0, 0);
+    Module.__einkRefreshes++;
+  }, px, w, h);
+}
+#endif // SIM_EINK_PANEL_W
 #endif // __EMSCRIPTEN__

variants/sim/web/index.html

@@ -158,7 +158,13 @@
 
   <div id="log"></div>
 
-  <script src="build/meshcore_sim.js"></script>
+  <!-- ?build=meshcore_sim_eink_landscape (or _portrait) loads another build of
+       the same UI; the e-ink driver sizes the canvas itself. -->
+  <script>
+    document.write('<script src="build/' +
+      (new URLSearchParams(location.search).get('build') || 'meshcore_sim').replace(/[^\w]/g, '') +
+      '.js"><\/script>');
+  </script>
   <script>
     const statusEl = document.getElementById('status');
     const logEl = document.getElementById('log');
@@ -209,11 +215,12 @@
       }
     }
 
-    if (typeof MeshCoreSim !== 'function') {
+    const SimFactory = window.MeshCoreSimEink || window.MeshCoreSim;
+    if (typeof SimFactory !== 'function') {
       statusEl.textContent = 'error: build/meshcore_sim.js missing or failed to load -- run variants/sim/build_wasm.sh first.';
     } else {
       statusEl.textContent = 'booting wasm module...';
-      MeshCoreSim().then((Module) => {
+      SimFactory().then((Module) => {
         window.Module = Module;   // exposed for console poking while testing
         statusEl.textContent = 'running -- IDBFS-backed identity/prefs persist across a real reload.';
         log('module ready; sim_enqueue_key = ' + (typeof Module._sim_enqueue_key));

variants/sim/web/mesh.html

@@ -231,8 +231,14 @@
 
   <script src="build/meshcore_sim.js"></script>
   <script src="build/repeater/meshcore_sim_repeater.js"></script>
+  <!-- ?a=meshcore_sim_eink_landscape (or _portrait): A is that e-ink build. -->
+  <script>
+    const A_BUILD = (new URLSearchParams(location.search).get('a') || '').replace(/[^\w]/g, '');
+    if (A_BUILD) document.write('<script src="build/' + A_BUILD + '.js"><\/script>');
+  </script>
   <script>
     const logEl = document.getElementById('log');
+    const FactoryA = (opts) => (A_BUILD ? MeshCoreSimEink : MeshCoreSim)(opts);
     function log(msg) {
       const line = document.createElement('div');
       line.textContent = '[' + new Date().toISOString().substr(11, 12) + '] ' + msg;
@@ -384,7 +390,7 @@
     async function resetInstance(key) {
       log(`resetting instance ${key}...`);
       document.getElementById('status-' + key).textContent = 'resetting...';
-      if (key === 'A') A = wrapInstance(await MeshCoreSim({ simInstanceTag: 'A' }), 'A');
+      if (key === 'A') A = wrapInstance(await FactoryA({ simInstanceTag: 'A' }), 'A');
       else if (key === 'B') B = wrapInstance(await MeshCoreSim({ simInstanceTag: 'B' }), 'B');
       else if (key === 'R') R = wrapInstance(await MeshCoreSimRepeater({ simInstanceTag: 'R' }), 'R');
       await waitReady(key === 'A' ? A : key === 'B' ? B : R, 'status-' + key);
@@ -394,7 +400,7 @@
 
     async function main() {
       log('booting instance A (companion_radio)...');
-      const modA = await MeshCoreSim({ simInstanceTag: 'A' });
+      const modA = await FactoryA({ simInstanceTag: 'A' });
       log('booting instance B (companion_radio)...');
       const modB = await MeshCoreSim({ simInstanceTag: 'B' });
       log('booting instance R (simple_repeater)...');