Unify Signals/Channels around auto-naming, plot-by-channel, and shared vars

Devices: auto-name from OS-reported port description (Device Manager /
udev string) instead of a generic label; default Serial #Channels 1;
consistent simulate-mode checkbox across backends; inline device rename.

Channels: calibration/filters move out of Signals into a Channel
"Operation" (adds Scale/Offset alongside the existing math kinds);
single-physical-source Channels get an embedded Filters block; new
Channels auto-name/auto-ID from their source and reject duplicate
names/IDs on apply; "Create Channel" button on each Signal row; renamed
"Sources" -> "Signals" in the Channels UI; Signals' READ/WRITE dir badge
(was silently-broken IN/OUT) now reflects the real writable flag.

Plot: default layout is one pane per Channel (not per device, not raw
Signals) titled by channel name; "+ Add Channel" is a checkbox dialog
instead of an inline dropdown; traces get up/down reorder; live unit
changes (e.g. a Mark-10 gauge switching lb/kgF/N/ozF) propagate to an
open pane's axis label without clobbering a manually-typed one.

Control Panel: hardware assignment now picks from the same writable-
Signals list instead of a separate device/channel combo with a
hardcoded Arduino pin list; stale visual indicator when a control's
target device/channel disconnects or disappears; documented the `vars`
bridge (Control Panel On Action Script <-> Channel scripts) in both
directions' help text and script templates.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 31 insertions, 65 deletions

diff --git a/ui/control_editor.py b/ui/control_editor.py
index 111a71f..d167517 100644
--- a/ui/control_editor.py
+++ b/ui/control_editor.py
@@ -204,31 +204,26 @@ class ControlEditorDialog(QDialog):
 
         root.addWidget(id_grp)
 
-        # ── Device & channel ────────────────────────────────────────────
+        # ── Target signal ────────────────────────────────────────────────
+        # Sourced from the same writable-channel set Configuration > Channels >
+        # Signals shows as "OUT" — the Signals tab is the central place hardware
+        # endpoints (including button targets) are registered.
         hw_grp  = QGroupBox("Hardware Assignment")
         hw_form = QFormLayout(hw_grp); hw_form.setContentsMargins(10, 16, 10, 10)
 
-        self._dev_cb = QComboBox()
-        self._dev_cb.addItem("— none —", userData="")
+        self._target_cb = QComboBox()
+        self._target_cb.addItem("— none —", userData=("", ""))
         for dev in self.registry.all_instances():
-            label = f"{dev.info.device_id}  ({dev.info.name})"
-            self._dev_cb.addItem(label, userData=dev.info.device_id)
-        self._dev_cb.currentIndexChanged.connect(self._on_dev_changed)
-        hw_form.addRow("Device:", self._dev_cb)
-
-        self._ch_cb = QComboBox()
-        self._ch_cb.setEditable(True)   # allow typing custom pin like "D7"
-        self._ch_cb.setInsertPolicy(QComboBox.InsertPolicy.NoInsert)
-        hw_form.addRow("Channel / Pin:", self._ch_cb)
+            for ch in dev.info.channels:
+                if not ch.enabled or not ch.writable:
+                    continue
+                label = f"{dev.info.device_id} / {ch.name}  ({ch.channel_id})"
+                self._target_cb.addItem(label, userData=(dev.info.device_id, ch.channel_id))
+        hw_form.addRow("Target Signal:", self._target_cb)
 
         self._active_low_chk = QCheckBox("Active-low output (ON sends LOW)")
         hw_form.addRow("Polarity:", self._active_low_chk)
 
-        self._ch_hint = QLabel("")
-        self._ch_hint.setObjectName("traceSource")
-        self._ch_hint.setWordWrap(True)
-        hw_form.addRow(self._ch_hint)
-
         root.addWidget(hw_grp)
 
         # ── Type-specific params ────────────────────────────────────────
@@ -256,7 +251,10 @@ class ControlEditorDialog(QDialog):
         _help = QLabel(
             "Runs every time this control changes value.\n"
             "Available: value, channel_id, device_id, vars (shared dict), "
-            "channels (latest values by channel_id), math"
+            "channels (latest values by channel_id), math\n"
+            "vars set here are readable from any Channel's script "
+            "(Configuration > Channels) via vars.get('key', default) — "
+            "this is how a button feeds a value into Channel math."
         )
         _help.setObjectName("traceSource"); _help.setWordWrap(True)
         script_lay.addWidget(_help)
@@ -316,21 +314,22 @@ class ControlEditorDialog(QDialog):
         self._type_cb.setCurrentIndex(idx)
         self._title_edit.setText(self.spec.title)
 
-        # Device
-        for i in range(self._dev_cb.count()):
-            if self._dev_cb.itemData(i) == self.spec.device_id:
-                self._dev_cb.setCurrentIndex(i); break
-
-        # Channel (populated after device selection)
-        self._on_dev_changed()
+        # Target signal
         found = False
-        for i in range(self._ch_cb.count()):
-            if self._ch_cb.itemData(i) == self.spec.channel_id:
-                self._ch_cb.setCurrentIndex(i)
+        target = (self.spec.device_id, self.spec.channel_id)
+        for i in range(self._target_cb.count()):
+            if self._target_cb.itemData(i) == target:
+                self._target_cb.setCurrentIndex(i)
                 found = True
                 break
-        if not found:
-            self._ch_cb.setCurrentText(self.spec.channel_id)
+        if not found and self.spec.device_id:
+            # Not in the current writable-signal list (e.g. a legacy raw pin
+            # target, or the channel/device is now disabled/removed) — keep it
+            # as a synthetic entry so editing this control doesn't silently
+            # clear its saved hardware assignment.
+            label = f"{self.spec.device_id} / {self.spec.channel_id}  (not currently available)"
+            self._target_cb.addItem(label, userData=target)
+            self._target_cb.setCurrentIndex(self._target_cb.count() - 1)
         self._active_low_chk.setChecked(bool(self.spec.active_low))
 
         # Params
@@ -351,50 +350,17 @@ class ControlEditorDialog(QDialog):
            self._title_edit.text() in CONTROL_TYPES:
             self._title_edit.setText(type_name)
 
-    def _on_dev_changed(self):
-        self._ch_cb.clear()
-        dev_id = self._dev_cb.currentData()
-        if not dev_id:
-            self._ch_hint.setText("No device selected — type a channel manually")
-            return
-        dev = self.registry.get_instance(dev_id)
-        if not dev:
-            return
-        # Add actual channels (skip disabled — can't be driven while switched
-        # off — and skip read-only channels — a control writes, so a channel
-        # with no write mapping should never be offered as a target)
-        for ch in dev.info.channels:
-            if not ch.enabled or not ch.writable:
-                continue
-            self._ch_cb.addItem(f"{ch.name}  ({ch.channel_id})",
-                                userData=ch.channel_id)
-        # For Arduino backends also suggest digital pins for output
-        if hasattr(dev, "backend") and dev.backend == "arduino":
-            self._ch_cb.insertSeparator(self._ch_cb.count())
-            for pin in ["D5", "D6", "D7", "D8", "D9", "D10", "D11", "D13"]:
-                self._ch_cb.addItem(f"{pin}  (digital out)", userData=pin)
-            self._ch_hint.setText(
-                "Analog pins (A0…) for reading.\n"
-                "Digital pins (D5…) for on/off output.\n"
-                "D9, D10, D11 support PWM."
-            )
-        else:
-            self._ch_hint.setText("")
-
     def _on_ok(self):
         ctype = self._type_cb.currentText()
         title = self._title_edit.text().strip() or ctype
 
-        # Resolve channel_id — prefer userData if it's a real combo item
-        ch_text = self._ch_cb.currentText().strip()
-        ch_data = self._ch_cb.currentData()
-        channel_id = ch_data if ch_data else ch_text.split()[0]  # strip "(name)" part
+        dev_id, channel_id = self._target_cb.currentData() or ("", "")
 
         spec = ControlSpec(
             control_type=ctype,
             title=title,
             icon=CONTROL_ICONS.get(ctype, "⚙"),
-            device_id=self._dev_cb.currentData() or "",
+            device_id=dev_id,
             channel_id=channel_id,
             active_low=self._active_low_chk.isChecked(),
             on_action_script=self._script_edit.toPlainText().strip(),