diff --git a/firmware/patternflow/config.h b/firmware/patternflow/config.h
index c396dce97..af335c10c 100644
--- a/firmware/patternflow/config.h
+++ b/firmware/patternflow/config.h
@@ -78,33 +78,37 @@ constexpr float EULER      = 2.71828182845904523536f;
 // pattern with PFCanvas::setFrame(). See README.md.
 // Running a non-stock panel? Please report how it went, working or not:
 // https://github.com/engmung/Patternflow/issues/224
-#define PANEL_GEOM_128x64_SINGLE 1  // one 128×64 module (stock)
-#define PANEL_GEOM_64x64_SINGLE  2  // one 64×64 module
-#define PANEL_GEOM_64x64_CHAIN2  3  // two 64×64 modules daisy-chained → 128×64
+//
+// The ids and the sizes come from shared/constants.json, which the site
+// reads too.
+#include "src/core_shared.h"
+#define PANEL_GEOM_128x64_SINGLE PF_SHARED_PANEL_GEOM_128x64_SINGLE  // one 128×64 module (stock)
+#define PANEL_GEOM_64x64_SINGLE  PF_SHARED_PANEL_GEOM_64x64_SINGLE   // one 64×64 module
+#define PANEL_GEOM_64x64_CHAIN2  PF_SHARED_PANEL_GEOM_64x64_CHAIN2   // two 64×64 modules daisy-chained → 128×64
 
 // #define PANEL_GEOMETRY PANEL_GEOM_64x64_CHAIN2
 #ifndef PANEL_GEOMETRY
-#define PANEL_GEOMETRY PANEL_GEOM_128x64_SINGLE
+#define PANEL_GEOMETRY PF_SHARED_PANEL_GEOM_DEFAULT
 #endif
 
 #if PANEL_GEOMETRY == PANEL_GEOM_64x64_SINGLE
-  #define PANEL_PHYS_W 64
-  #define PANEL_PHYS_H 64
-  #define PANEL_CHAIN  1
-  #define PANEL_RES_W  64
-  #define PANEL_RES_H  64
+  #define PANEL_PHYS_W PF_SHARED_PANEL_GEOM_64x64_SINGLE_PHYS_W
+  #define PANEL_PHYS_H PF_SHARED_PANEL_GEOM_64x64_SINGLE_PHYS_H
+  #define PANEL_CHAIN  PF_SHARED_PANEL_GEOM_64x64_SINGLE_CHAIN
+  #define PANEL_RES_W  PF_SHARED_PANEL_GEOM_64x64_SINGLE_RES_W
+  #define PANEL_RES_H  PF_SHARED_PANEL_GEOM_64x64_SINGLE_RES_H
 #elif PANEL_GEOMETRY == PANEL_GEOM_64x64_CHAIN2
-  #define PANEL_PHYS_W 64
-  #define PANEL_PHYS_H 64
-  #define PANEL_CHAIN  2
-  #define PANEL_RES_W  128
-  #define PANEL_RES_H  64
+  #define PANEL_PHYS_W PF_SHARED_PANEL_GEOM_64x64_CHAIN2_PHYS_W
+  #define PANEL_PHYS_H PF_SHARED_PANEL_GEOM_64x64_CHAIN2_PHYS_H
+  #define PANEL_CHAIN  PF_SHARED_PANEL_GEOM_64x64_CHAIN2_CHAIN
+  #define PANEL_RES_W  PF_SHARED_PANEL_GEOM_64x64_CHAIN2_RES_W
+  #define PANEL_RES_H  PF_SHARED_PANEL_GEOM_64x64_CHAIN2_RES_H
 #else
-  #define PANEL_PHYS_W 128
-  #define PANEL_PHYS_H 64
-  #define PANEL_CHAIN  1
-  #define PANEL_RES_W  128
-  #define PANEL_RES_H  64
+  #define PANEL_PHYS_W PF_SHARED_PANEL_GEOM_128x64_SINGLE_PHYS_W
+  #define PANEL_PHYS_H PF_SHARED_PANEL_GEOM_128x64_SINGLE_PHYS_H
+  #define PANEL_CHAIN  PF_SHARED_PANEL_GEOM_128x64_SINGLE_CHAIN
+  #define PANEL_RES_W  PF_SHARED_PANEL_GEOM_128x64_SINGLE_RES_W
+  #define PANEL_RES_H  PF_SHARED_PANEL_GEOM_128x64_SINGLE_RES_H
 #endif
 
 #if PANEL_RES_W != (PANEL_PHYS_W * PANEL_CHAIN)
diff --git a/firmware/patternflow/net_config.h b/firmware/patternflow/net_config.h
index b5134678f..2ebb142d8 100644
--- a/firmware/patternflow/net_config.h
+++ b/firmware/patternflow/net_config.h
@@ -32,6 +32,8 @@
 #include "patternflow_secrets.h"
 #endif
 
+#include "src/core_shared.h"
+
 // ── Wi-Fi ────────────────────────────────────────────────────────────
 // Whether the panel has a radio at all. 0 makes a USB-only instrument:
 // everything network-side (console, OTA, every feature that dials out)
@@ -190,7 +192,8 @@
 // it into virtual knob deltas (applyLaneMotion), so EVERY encoder-driven
 // pattern reacts with no per-pattern code. This is how many knob clicks a
 // full 0..1 swing maps to. Higher = stronger response. No per-frame clamp,
-// so the value tracks without lag.
+// so the value tracks without lag. The default is a parameter's whole range,
+// two turns of 24 detents (src/core_shared.h).
 //
 // The old name is honoured below because a firmware built elsewhere may
 // already set it in its overrides.h, and a rename that silently ignores
@@ -199,6 +202,6 @@
 #ifdef PF_AUDIO_VIRTUAL_KNOB_SCALE
 #define PF_LANE_MOTION_SCALE PF_AUDIO_VIRTUAL_KNOB_SCALE
 #else
-#define PF_LANE_MOTION_SCALE 48.0f
+#define PF_LANE_MOTION_SCALE ((float)(PF_SHARED_DETENTS_PER_TURN * PF_SHARED_TURNS_PER_FULL_RANGE))
 #endif
 #endif
diff --git a/firmware/patternflow/patternflow.ino b/firmware/patternflow/patternflow.ino
index cb4094307..f451f8ebf 100644
--- a/firmware/patternflow/patternflow.ino
+++ b/firmware/patternflow/patternflow.ino
@@ -270,7 +270,7 @@ bool updateDirty = false;
 // loop() draws it. -1 when nothing is being received.
 volatile int uploadPctShown = -1;
 
-const uint32_t MODE_HOLD_MS = 1000;
+const uint32_t MODE_HOLD_MS = PF_SHARED_LONG_PRESS_MS;
 const uint32_t BRIGHTNESS_IDLE_MS = 5000;
 // How long the value has to be still before it is written to NVS - the
 // console's slider sends a step for every pixel of a drag.
diff --git a/firmware/patternflow/src/core_bus.h b/firmware/patternflow/src/core_bus.h
index 29dfedcfc..d423228e1 100644
--- a/firmware/patternflow/src/core_bus.h
+++ b/firmware/patternflow/src/core_bus.h
@@ -23,13 +23,16 @@
 
 #include <Arduino.h>
 #include "core_encoders.h"  // InputFrame
+#include "core_shared.h"
 
 // The wire scale of an absolute channel: 0..PF_BUS_MAX, integer. Everything
 // that writes the bus — MQTT param/1..4, POST /api/params, a .pfs cue, a MIDI
 // CC — speaks this scale, and the site's Director bakes to it
 // (BUS_WIRE_MAX in web/src/lib/pattern/controls.ts). abi/pf_params.h clamps
 // to the same literal and cannot be changed to this name: the ABI is frozen.
-#define PF_BUS_MAX 1000
+// The number is BUS_MAX in shared/constants.json, and check:shared holds the
+// ABI's literal to it.
+#define PF_BUS_MAX PF_SHARED_BUS_MAX
 
 namespace PatternflowBus {
 
@@ -87,9 +90,9 @@ inline void applyRemoteParam(int index, long value) {
     if (diff != 0) {
       const int32_t acc =
           __atomic_add_fetch(&clickResidual[index], (int32_t)diff, __ATOMIC_RELAXED);
-      const int32_t d = acc / 10;  // truncates toward zero, both signs
+      const int32_t d = acc / PF_SHARED_BUS_UNITS_PER_CLICK;  // truncates toward zero, both signs
       if (d != 0) {
-        __atomic_fetch_sub(&clickResidual[index], d * 10, __ATOMIC_RELAXED);
+        __atomic_fetch_sub(&clickResidual[index], d * PF_SHARED_BUS_UNITS_PER_CLICK, __ATOMIC_RELAXED);
         __atomic_fetch_add(&pendingDelta[index], d, __ATOMIC_RELAXED);
       }
     }
diff --git a/firmware/patternflow/src/core_encoders.h b/firmware/patternflow/src/core_encoders.h
index 84cd93e81..b0d61299a 100644
--- a/firmware/patternflow/src/core_encoders.h
+++ b/firmware/patternflow/src/core_encoders.h
@@ -2,6 +2,7 @@
 #include <Arduino.h>
 #include <Preferences.h>
 #include "config.h"
+#include "core_shared.h"
 
 volatile long     encPos[4]    = {0, 0, 0, 0};   // sub-steps; 4 per detent
 volatile uint8_t  encState[4]  = {0, 0, 0, 0};   // last ACCEPTED (A<<1)|B
@@ -73,7 +74,9 @@ void IRAM_ATTR isr4() { handleEncoder(3, ENC4_A, ENC4_B); }
 // (namespace "pf_knobs"), set from the /knobs page (core_knobs_http.h).
 inline bool knobInvert[4] = {INVERT_ENCODER != 0, INVERT_ENCODER != 0,
                              INVERT_ENCODER != 0, INVERT_ENCODER != 0};
-inline int  knobSubSteps[4] = {4, 4, 4, 4};   // edges per click: 4, 2 or 1
+// Edges per click: 4, 2 or 1.
+inline int  knobSubSteps[4] = {PF_SHARED_EDGES_PER_DETENT, PF_SHARED_EDGES_PER_DETENT,
+                               PF_SHARED_EDGES_PER_DETENT, PF_SHARED_EDGES_PER_DETENT};
 // A settings change must not move a knob. The click count carries on from
 // where it was, counting the edges since the change in the new direction
 // and at the new size, so the frame's delta stays zero across a save.
@@ -86,7 +89,9 @@ inline long getClicks(int idx) {
   return knobClickBase[idx] + rel / knobSubSteps[idx];
 }
 
-inline int clampSubSteps(int v) { return (v == 1 || v == 2 || v == 4) ? v : 4; }
+inline int clampSubSteps(int v) {
+  return (v == 1 || v == 2 || v == 4) ? v : PF_SHARED_EDGES_PER_DETENT;
+}
 
 // Call on the frame task (the frame reads the same counters).
 inline void setKnobSettings(int idx, bool invert, int subSteps) {
@@ -140,7 +145,7 @@ struct Button {
   bool pressed() {
     bool cur = digitalRead(pin);
     uint32_t now = millis();
-    if (cur != lastState && (now - lastChangeMs) > 50) {
+    if (cur != lastState && (now - lastChangeMs) > PF_SHARED_BUTTON_DEBOUNCE_MS) {
       lastState = cur;
       lastChangeMs = now;
       if (cur == LOW) {
@@ -166,7 +171,7 @@ struct Button {
     return c;
   }
 
-  bool longPressed(uint32_t threshold = 1000) {
+  bool longPressed(uint32_t threshold = PF_SHARED_LONG_PRESS_MS) {
     if (!isDown()) return false;
     uint32_t now = millis();
     if (!longPressFired && (now - pressStartMs) > threshold) {
diff --git a/firmware/toolchain/check_midi.py b/firmware/toolchain/check_midi.py
index d654331ee..63185e122 100644
--- a/firmware/toolchain/check_midi.py
+++ b/firmware/toolchain/check_midi.py
@@ -13,7 +13,8 @@ def main():
     compiler, env = compiler_environment()
     with tempfile.TemporaryDirectory(prefix='patternflow-midi-') as directory:
         work = Path(directory)
-        for name in ('features/midi/core_midi.h', 'features/midi/midi_queue.h', 'src/core_bus.h'):
+        for name in ('features/midi/core_midi.h', 'features/midi/midi_queue.h', 'src/core_bus.h',
+                     'src/core_shared.h'):
             dest = work / name
             dest.parent.mkdir(parents=True, exist_ok=True)
             dest.write_bytes((ROOT / 'firmware/patternflow' / name).read_bytes())