Remove unnecessary comments, clean up code

README.md

@@ -5,17 +5,17 @@ A BLE HID mouse that uses the onboard IMU of a **Seeed XIAO nRF52840 Sense** to
 ## Features
 
 - **6-DoF gyro + accelerometer** via LSM6DS3 with complementary filter
-- **Hardware tap detection** — single tap = left click, double tap = right click
+- **Hardware tap detection** - single tap = left click, double tap = right click
-- **BLE HID mouse** — works natively on Windows, macOS, Linux, Android, iOS
+- **BLE HID mouse** - works natively on Windows, macOS, Linux, Android, iOS
-- **BLE Battery Service** — charge level visible in OS Bluetooth settings
+- **BLE Battery Service** - charge level visible in OS Bluetooth settings
-- **Web config UI** (`web/index.html`) — configure over BLE from any Chrome/Edge browser, no app install
+- **Web config UI** (`web/index.html`) - configure over BLE from any Chrome/Edge browser, no app install
-- **Flash persistence** — config survives power cycles (LittleFS)
+- **Flash persistence** - config survives power cycles (LittleFS)
-- **Live IMU stream** — 20 Hz gyro/accel data streamed to the web UI visualiser
+- **Live IMU stream** - 20 Hz gyro/accel data streamed to the web UI visualiser
-- **Live telemetry** — temperature, uptime, click counts, gyro bias RMS, recal count
+- **Live telemetry** - temperature, uptime, click counts, gyro bias RMS, recal count
-- **Temperature compensation** — gyro drift correction by Δ temperature since last calibration
+- **Temperature compensation** - gyro drift correction by Δ temperature since last calibration
-- **Auto-recalibration** — recalibrates automatically after 5 minutes of idle
+- **Auto-recalibration** - recalibrates automatically after 5 minutes of idle
-- **Configurable charge rate** — OFF / 50 mA slow / 100 mA fast via BQ25100 HICHG pin
+- **Configurable charge rate** - OFF / 50 mA slow / 100 mA fast via BQ25100 HICHG pin
-- **Boot-loop detection** — 3 rapid reboots trigger safe mode (config service disabled, flash wiped)
+- **Boot-loop detection** - 3 rapid reboots trigger safe mode (config service disabled, flash wiped)
 
 ## Hardware
 
@@ -26,22 +26,22 @@ A BLE HID mouse that uses the onboard IMU of a **Seeed XIAO nRF52840 Sense** to
 
 ## LED Status
 
-The XIAO has three user LEDs (active LOW — HIGH = off, LOW = on):
+The XIAO has three user LEDs (active LOW - HIGH = off, LOW = on):
 
 | LED | Pattern | Meaning |
 |---|---|---|
 | Blue | Single pulse every 10 s | BLE connected (heartbeat) |
 | Green | Single pulse every 10 s | Advertising / not connected (heartbeat) |
 | Green | Rapid flutter (~10 Hz) | Gyro calibration in progress |
-| Red | Fast blink (continuous) | IMU init failed — hardware fault |
+| Red | Fast blink (continuous) | IMU init failed - hardware fault |
-| Red | 3 slow blinks on boot | Boot-loop detected — entered safe mode |
+| Red | 3 slow blinks on boot | Boot-loop detected - entered safe mode |
 | Red | 6 rapid blinks | Battery critically low (< 3.10 V) |
 
 > **Blue** = BLE-related state. **Green** = device activity. **Red** = fault only.
 
 ## Web Config UI
 
-Open `web/index.html` in Chrome or Edge (desktop). Requires Web Bluetooth — enable it at `chrome://flags/#enable-web-bluetooth` on Linux.
+Open `web/index.html` in Chrome or Edge (desktop). Requires Web Bluetooth - enable it at `chrome://flags/#enable-web-bluetooth` on Linux.
 
 **Configurable parameters:**
 
@@ -56,8 +56,8 @@ Open `web/index.html` in Chrome or Edge (desktop). Requires Web Bluetooth — en
 
 **Commands:**
 
-- **Calibrate Gyro** — recalculates bias offset; hold the device still on a flat surface for ~1 s
+- **Calibrate Gyro** - recalculates bias offset; hold the device still on a flat surface for ~1 s
-- **Factory Reset** — wipes flash config, restores defaults
+- **Factory Reset** - wipes flash config, restores defaults
 
 ## Building
 

model/pointer.FCMacro

@@ -255,7 +255,7 @@ base = base.fuse(
         BAT_X + BAT_L, clip_y_start, WALL)
 )
 
-# Circular notch in back wall — centred on base
+# Circular notch in back wall - centred on base
 notch_cz = rail_z + LID_H
 base = base.cut(circular_notch(L, W / 2, notch_cz, NOTCH_R, NOTCH_DEPTH))
 

platformio.ini

@@ -1,4 +1,4 @@
-; ── PlatformIO project configuration ─────────────────────────────────────────
+;  PlatformIO project configuration 
 ; Board  : Seeed XIAO nRF52840 Sense
 ; Core   : Adafruit nRF52 Arduino (via Seeed platform-seeedboards)
 ; Flash  : adafruit-nrfutil over USB serial (same as Arduino IDE)
@@ -6,7 +6,7 @@
 ; First-time setup:
 ;   pip install adafruit-nrfutil          <- upload tool (once, globally)
 ;   pio run -t upload                     <- build + flash
-; ──────────────────────────────────────────────────────────────────────────────
+; 
 
 [platformio]
 src_dir = source
@@ -16,7 +16,7 @@ platform  = https://github.com/Seeed-Studio/platform-seeedboards.git
 board     = seeed-xiao-afruitnrf52-nrf52840
 framework = arduino
 
-; ── Upload ────────────────────────────────────────────────────────────────────
+;  Upload 
 ; The XIAO uses a UF2 bootloader that accepts firmware via adafruit-nrfutil.
 ; Double-tap the reset button to enter bootloader (red LED pulses) before
 ; flashing if the board isn't auto-reset by the tool.
@@ -25,21 +25,21 @@ upload_speed    = 115200
 ; Uncomment and set the correct port if auto-detect fails:
 ; upload_port   = COM3
 
-; ── Build scripts ─────────────────────────────────────────────────────────────
+;  Build scripts 
 extra_scripts = pre:scripts/git_hash.py
 
-; ── Build flags ───────────────────────────────────────────────────────────────
+;  Build flags 
 build_flags =
     -DARDUINO_Seeed_XIAO_nRF52840_Sense
     -DNRF52840_XXAA
     -DTARGET_SEEED_XIAO_NRF52840_SENSE
 
-; ── Libraries ─────────────────────────────────────────────────────────────────
+;  Libraries 
 ; bluefruit.h, Adafruit_LittleFS.h, InternalFileSystem.h are bundled with
 ; the Adafruit nRF52 core and do NOT need to be listed here.
 ; Only external libraries are listed:
 lib_deps =
     Seeed-Studio/Seeed Arduino LSM6DS3 @ ^2.0.3
 
-; ── Serial monitor ────────────────────────────────────────────────────────────
+;  Serial monitor 
 monitor_speed = 115200

scripts/git_hash.py

@@ -8,7 +8,7 @@ Usage: referenced from platformio.ini as:
 """
 import subprocess, os, re
 
-Import("env")  # noqa: F821 — PlatformIO injects this
+Import("env")  # noqa: F821 - PlatformIO injects this
 
 def get_git_hash():
     try:
@@ -27,14 +27,14 @@ def get_git_hash():
 git_hash = get_git_hash()
 print(f"[git_hash] short hash = {git_hash}")
 
-# ── Inject into firmware build ────────────────────────────────────────────────
+#  Inject into firmware build 
 env.Append(CPPDEFINES=[("GIT_HASH", f'\\"{git_hash}\\"')])  # noqa: F821
 
-# ── Write web/version.js ──────────────────────────────────────────────────────
+#  Write web/version.js 
 web_dir  = os.path.join(env.subst("$PROJECT_DIR"), "web")  # noqa: F821
 ver_file = os.path.join(web_dir, "version.js")
 os.makedirs(web_dir, exist_ok=True)
 with open(ver_file, "w") as f:
-    f.write(f"// Auto-generated by scripts/git_hash.py — do not edit\n")
+    f.write(f"// Auto-generated by scripts/git_hash.py - do not edit\n")
     f.write(f"const FIRMWARE_BUILD_HASH = '{git_hash}';\n")
 print(f"[git_hash] wrote {ver_file}")

source/battery.cpp

@@ -13,7 +13,7 @@ void initBatteryADC() {
   pinMode(PIN_VBAT_ENABLE, OUTPUT); digitalWrite(PIN_VBAT_ENABLE, LOW);
   pinMode(PIN_VBAT_READ, INPUT);
   analogReference(AR_INTERNAL_3_0); analogReadResolution(12);
-  // Warm up with a few reads (no delay — just discard results)
+  // Warm up with a few reads (no delay - just discard results)
   for (int i=0; i<8; i++) analogRead(PIN_VBAT_READ);
 }
 
@@ -34,7 +34,7 @@ void updateBattery() {
   float v = readBatteryVoltage(); int pct = batteryPercent(v);
   bool chg = (digitalRead(PIN_CHG) == LOW);
   ChargeStatus status = chg ? (pct >= 99 ? CHGSTAT_FULL : CHGSTAT_CHARGING) : CHGSTAT_DISCHARGING;
-  // Only write BLE Battery Service when connected — blebas.write() blocks on the
+  // Only write BLE Battery Service when connected - blebas.write() blocks on the
   // SoftDevice ATT layer and causes 30-40ms loop stalls when called during advertising.
   if (Bluefruit.connected()) blebas.write(pct);
   lastChargeStatus = status;
@@ -44,7 +44,7 @@ void updateBattery() {
   const char* st[] = {"discharging","charging","full"};
   Serial.print("[BATT] "); Serial.print(v,2); Serial.print("V ");
   Serial.print(pct); Serial.print("% "); Serial.println(st[status]);
-  // Critical battery alert — only blink when not connected to avoid blocking BLE scheduler.
+  // Critical battery alert - only blink when not connected to avoid blocking BLE scheduler.
   // 6 × 160ms = 960ms hard block; skip during active connection.
   if (status == CHGSTAT_DISCHARGING && v < BATT_CRITICAL && !Bluefruit.connected())
     for (int i=0; i<6; i++) { digitalWrite(LED_RED,LOW); delay(80); digitalWrite(LED_RED,HIGH); delay(80); }

source/ble_config.cpp

@@ -8,7 +8,7 @@
 using namespace Adafruit_LittleFS_Namespace;
 extern File cfgFile;
 
-// ─── BLE Config Service objects ───────────────────────────────────────────────
+// BLE Config Service objects 
 #ifndef GIT_HASH
   #define GIT_HASH "unknown"
 #endif
@@ -26,7 +26,7 @@ BLECharacteristic cfgGitHash   (0x1239);  // GitHash     R    8 bytes (7-char ha
 #endif
 #endif
 
-// ─── Charge mode ──────────────────────────────────────────────────────────────
+// Charge mode 
 void applyChargeMode(ChargeMode mode) {
   switch (mode) {
     case CHARGE_OFF:  pinMode(PIN_HICHG, INPUT_PULLUP);                          break;
@@ -37,7 +37,7 @@ void applyChargeMode(ChargeMode mode) {
   Serial.print("[CHG] "); Serial.println(n[mode]);
 }
 
-// ─── Config persistence ───────────────────────────────────────────────────────
+// Config persistence 
 void loadConfig() {
   InternalFS.begin();
   cfgFile.open(CONFIG_FILENAME, FILE_O_READ);
@@ -57,11 +57,11 @@ void saveConfig() {
   cfgFile.open(CONFIG_FILENAME, FILE_O_WRITE);
   if (cfgFile) { cfgFile.write((uint8_t*)&cfg, sizeof(cfg)); cfgFile.close(); }
   unsigned long elapsed = millis() - t0;
-  if (elapsed > 5) { Serial.print("[CFG] Saved ("); Serial.print(elapsed); Serial.println("ms — flash block)"); }
+  if (elapsed > 5) { Serial.print("[CFG] Saved ("); Serial.print(elapsed); Serial.println("ms - flash block)"); }
   else               { Serial.println("[CFG] Saved"); }
 }
 
-// ─── ConfigBlob push ─────────────────────────────────────────────────────────
+// ConfigBlob push 
 #ifdef FEATURE_CONFIG_SERVICE
 void pushConfigBlob() {
   ConfigBlob b;
@@ -103,7 +103,7 @@ void factoryReset() {
   Serial.println("[CFG] Factory reset complete");
 }
 
-// ─── BLE callbacks ────────────────────────────────────────────────────────────
+// BLE callbacks 
 #ifdef FEATURE_CONFIG_SERVICE
 void onConfigBlobWrite(uint16_t h, BLECharacteristic* c, uint8_t* d, uint16_t l) {
   if (l != sizeof(ConfigBlob)) { Serial.println("[CFG] Bad blob length"); return; }
@@ -134,7 +134,7 @@ void onConfigBlobWrite(uint16_t h, BLECharacteristic* c, uint8_t* d, uint16_t l)
     setupPhysicalButtons();   // reconfigure pins immediately (no restart needed)
   #endif
   saveConfig();
-  Serial.print("[CFG] Written — sens="); Serial.print(cfg.sensitivity,0);
+  Serial.print("[CFG] Written - sens="); Serial.print(cfg.sensitivity,0);
   Serial.print(" dz="); Serial.print(cfg.deadZone,3);
   Serial.print(" tapThr="); Serial.print(cfg.tapThreshold);
   Serial.print(" tapAction="); Serial.println(cfg.tapAction);
@@ -153,7 +153,7 @@ void onImuStreamCccd(uint16_t conn_hdl, BLECharacteristic* chr, uint16_t value)
 }
 #endif
 
-// ─── BLE config service setup ─────────────────────────────────────────────────
+// BLE config service setup 
 void setupConfigService() {
   cfgService.begin();
 
@@ -170,7 +170,7 @@ void setupConfigService() {
   cfgCommand.setWriteCallback(onCommandWrite);
   cfgCommand.begin();
 
-  // Git hash — 8-byte fixed field (7 hex chars + NUL), read-only
+  // Git hash - 8-byte fixed field (7 hex chars + NUL), read-only
   cfgGitHash.setProperties(CHR_PROPS_READ);
   cfgGitHash.setPermission(SECMODE_OPEN, SECMODE_NO_ACCESS);
   cfgGitHash.setFixedLen(8);
@@ -206,7 +206,7 @@ void setupConfigService() {
 }
 #endif // FEATURE_CONFIG_SERVICE
 
-// ─── Telemetry push ───────────────────────────────────────────────────────────
+// Telemetry push 
 #ifdef FEATURE_TELEMETRY
 void pushTelemetry(unsigned long now) {
   telem.uptimeSeconds = now / 1000;

source/buttons.cpp

@@ -7,7 +7,7 @@ extern BLEHidAdafruit blehid;
 
 static uint8_t physBtnMask = 0;   // bitmask of currently-pressed physical buttons
 
-// ─── Setup ────────────────────────────────────────────────────────────────────
+// Setup 
 void setupPhysicalButtons() {
   // Release any held physical buttons before reconfiguring
   if (physBtnMask && Bluefruit.connected()) { blehid.mouseButtonRelease(); }
@@ -30,7 +30,7 @@ void setupPhysicalButtons() {
   }
 }
 
-// ─── Poll and report ──────────────────────────────────────────────────────────
+// Poll and report 
 // Called every loop iteration (before rate limiter) for immediate response.
 // Uses active-low logic: INPUT_PULLUP, button connects pin to GND.
 void processPhysicalButtons() {

source/config.h

@@ -1,7 +1,7 @@
 #pragma once
 #include <Arduino.h>
 
-// ─── Feature Flags ────────────────────────────────────────────────────────────
+// Feature Flags 
 #define FEATURE_CONFIG_SERVICE
 #define FEATURE_TELEMETRY
 #define FEATURE_IMU_STREAM
@@ -12,10 +12,10 @@
 #define FEATURE_BOOT_LOOP_DETECT
 #define FEATURE_PHYSICAL_BUTTONS
 
-// ─── Debug ────────────────────────────────────────────────────────────────────
+// Debug 
 // #define DEBUG
 
-// ─── ATT table size ───────────────────────────────────────────────────────────
+// ATT table size 
 #define _ATT_BASE 900
 #ifdef FEATURE_CONFIG_SERVICE
   #define _ATT_CFG 100   // +20 for cfgGitHash characteristic
@@ -35,7 +35,7 @@
 #define ATT_TABLE_SIZE_CALC (_ATT_BASE + _ATT_CFG + _ATT_TELEM + _ATT_STREAM)
 #define ATT_TABLE_SIZE (ATT_TABLE_SIZE_CALC < 1536 ? 1536 : ATT_TABLE_SIZE_CALC)
 
-// ─── IMU register addresses ───────────────────────────────────────────────────
+// IMU register addresses 
 #define REG_CTRL1_XL    0x10
 #define REG_TAP_CFG     0x58
 #define REG_TAP_THS_6D  0x59
@@ -46,20 +46,20 @@
 #define REG_OUT_TEMP_L  0x20
 #define REG_OUT_TEMP_H  0x21
 
-// ─── Pins ─────────────────────────────────────────────────────────────────────
+// Pins 
 #define PIN_VBAT_ENABLE (14)
 #define PIN_VBAT_READ   (32)
 #define PIN_CHG         (23)
 #define PIN_HICHG       (22)
 
-// ─── Persistence ──────────────────────────────────────────────────────────────
+// Persistence 
 #define CONFIG_FILENAME  "/imu_mouse_cfg.bin"
 #define CONFIG_MAGIC     0xDEAD123DUL
 
-// ─── Physical button sentinel ─────────────────────────────────────────────────
+// Physical button sentinel 
 #define BTN_PIN_NONE  0xFF   // Stored in btn*Pin when that button is disabled
 
-// ─── Runtime feature-override flags (cfg.featureFlags bitmask) ───────────────
+// Runtime feature-override flags (cfg.featureFlags bitmask) 
 // These mirror the compile-time FEATURE_* defines but can be toggled at runtime
 // via the web UI and persisted in flash.  Bits not listed here are reserved = 0.
 #define FLAG_TAP_ENABLED        0x01  // Tap detection active (requires restart)
@@ -67,12 +67,12 @@
 #define FLAG_AUTO_RECAL_ENABLED 0x04  // Auto-recalibrate after long idle
 #define FLAG_ALL_DEFAULT        (FLAG_TAP_ENABLED | FLAG_TEMP_COMP_ENABLED | FLAG_AUTO_RECAL_ENABLED)
 
-// ─── Enums ────────────────────────────────────────────────────────────────────
+// Enums 
 enum CurveType   : uint8_t { CURVE_LINEAR=0, CURVE_SQUARE=1, CURVE_SQRT=2 };
 enum ChargeMode  : uint8_t { CHARGE_OFF=0,   CHARGE_SLOW=1,  CHARGE_FAST=2 };
 enum ChargeStatus: uint8_t { CHGSTAT_DISCHARGING=0, CHGSTAT_CHARGING=1, CHGSTAT_FULL=2 };
 
-// ─── Tap action types ─────────────────────────────────────────────────────────
+// Tap action types 
 // TAP_ACTION_KEY: fires a raw HID keycode (tapKey) with optional modifier (tapMod).
 // Modifier byte: bit0=Ctrl, bit1=Shift, bit2=Alt, bit3=GUI (same as HID modifier byte).
 enum TapAction : uint8_t {
@@ -82,7 +82,7 @@ enum TapAction : uint8_t {
   TAP_ACTION_KEY    = 3,
 };
 
-// ─── Config (stored in flash) ─────────────────────────────────────────────────
+// Config (stored in flash) 
 struct Config {
   uint32_t   magic;
   float      sensitivity;
@@ -97,7 +97,7 @@ struct Config {
   uint8_t    tapMod;       // HID modifier byte (used when tapAction == TAP_ACTION_KEY)
   float      jerkThreshold;    // jerk² threshold for tap-freeze detection
   uint8_t    tapFreezeEnabled; // 1 = enable jerk-based cursor freeze during taps
-  uint8_t    featureFlags;     // bitmask of FLAG_* — runtime feature overrides
+  uint8_t    featureFlags;     // bitmask of FLAG_* - runtime feature overrides
   uint8_t    btnLeftPin;       // BTN_PIN_NONE or Arduino pin number (0-10 = D0-D10)
   uint8_t    btnRightPin;
   uint8_t    btnMiddlePin;
@@ -105,7 +105,7 @@ struct Config {
 extern Config cfg;
 extern const Config CFG_DEFAULTS;
 
-// ─── ConfigBlob (over BLE, 25 bytes) ─────────────────────────────────────────
+// ConfigBlob (over BLE, 25 bytes) 
 struct __attribute__((packed)) ConfigBlob {
   float   sensitivity;       // [0]
   float   deadZone;          // [4]
@@ -119,14 +119,14 @@ struct __attribute__((packed)) ConfigBlob {
   uint8_t tapMod;            // [18]  HID modifier
   uint8_t tapFreezeEnabled;  // [19]  1 = enable jerk-based cursor freeze during taps
   float   jerkThreshold;     // [20]  jerk² tap-freeze threshold
-  uint8_t featureFlags;      // [24]  FLAG_* bitmask — runtime feature overrides
+  uint8_t featureFlags;      // [24]  FLAG_* bitmask - runtime feature overrides
   uint8_t btnLeftPin;        // [25]  BTN_PIN_NONE or Arduino pin (0-10 = D0-D10)
   uint8_t btnRightPin;       // [26]
   uint8_t btnMiddlePin;      // [27]
 };
 static_assert(sizeof(ConfigBlob) == 28, "ConfigBlob must be 28 bytes");
 
-// ─── TelemetryPacket (24 bytes) ───────────────────────────────────────────────
+// TelemetryPacket (24 bytes) 
 #ifdef FEATURE_TELEMETRY
 struct __attribute__((packed)) TelemetryPacket {
   uint32_t uptimeSeconds;   // [0]
@@ -143,7 +143,7 @@ static_assert(sizeof(TelemetryPacket) == 28, "TelemetryPacket must be 28 bytes")
 extern TelemetryPacket telem;
 #endif
 
-// ─── ImuPacket (14 bytes) ─────────────────────────────────────────────────────
+// ImuPacket (14 bytes) 
 #ifdef FEATURE_IMU_STREAM
 struct __attribute__((packed)) ImuPacket {
   int16_t  gyroX_mDPS;  // [0]  pitch axis (nod up/down → cursor Y)
@@ -159,7 +159,7 @@ struct __attribute__((packed)) ImuPacket {
 static_assert(sizeof(ImuPacket) == 14, "ImuPacket must be 14 bytes");
 #endif
 
-// ─── Tuning constants ─────────────────────────────────────────────────────────
+// Tuning constants 
 extern const float ALPHA;
 extern const int   LOOP_RATE_MS;
 extern const int   BIAS_SAMPLES;
@@ -185,7 +185,7 @@ extern const float BATT_CRITICAL;
   extern const unsigned long AUTO_RECAL_MS;
 #endif
 
-// ─── Global state ─────────────────────────────────────────────────────────────
+// Global state 
 extern float angleX, angleY;
 extern float accumX, accumY;
 extern float gravX, gravY, gravZ;

source/imu.cpp

@@ -4,7 +4,7 @@
 
 LSM6DS3 imu(I2C_MODE, 0x6A);
 
-// ─── I2C helpers ──────────────────────────────────────────────────────────────
+// I2C helpers 
 void imuWriteReg(uint8_t reg, uint8_t val) {
   // LSM6DS3 is on Wire1 (internal I2C, SDA=P0.17, SCL=P0.16), NOT Wire (external pins 4/5)
   Wire1.beginTransmission(0x6A); Wire1.write(reg); Wire1.write(val); Wire1.endTransmission();
@@ -16,13 +16,13 @@ uint8_t imuReadReg(uint8_t reg) {
   return Wire1.available() ? Wire1.read() : 0;
 }
 
-// ─── Temperature ──────────────────────────────────────────────────────────────
+// Temperature 
 float readIMUTemp() {
   int16_t raw = (int16_t)((imuReadReg(REG_OUT_TEMP_H) << 8) | imuReadReg(REG_OUT_TEMP_L));
   return 25.0f + (float)raw / 256.0f;
 }
 
-// ─── Calibration ──────────────────────────────────────────────────────────────
+// Calibration 
 void calibrateGyroBias() {
   Serial.println("[CAL] Hold still...");
   double sx=0, sy=0, sz=0;
@@ -51,7 +51,7 @@ void calibrateGyroBias() {
   Serial.print(","); Serial.println(biasGZ,4);
 }
 
-// ─── Motion curve ─────────────────────────────────────────────────────────────
+// Motion curve 
 float applyCurve(float v) {
   switch (cfg.curve) {
     case CURVE_SQUARE: return (v >= 0 ? 1.f : -1.f) * v * v;

source/main.cpp

@@ -1,27 +1,12 @@
 /*
- * IMU BLE Mouse — Seeed XIAO nRF52840 Sense  (v3.4)
+ * IMU BLE Mouse - Seeed XIAO nRF52840 Sense  (v3.4)
  * ================================================================
- * Feature flags — comment out any line to disable that feature.
- * ATT table size is computed automatically from enabled features.
- * Start with minimal flags to isolate the SoftDevice RAM issue,
- * then re-enable one at a time.
- *
  * MINIMUM (just working mouse, no BLE config):
  *   leave only FEATURE_BATTERY_MONITOR + FEATURE_BOOT_LOOP_DETECT
  *
  * RECOMMENDED first test:
  *   enable FEATURE_CONFIG_SERVICE, keep TAP + STREAM + TELEMETRY off
  *
- * ── Feature flag index ───────────────────────────────────────────
- *   FEATURE_CONFIG_SERVICE    Custom GATT service (ConfigBlob + Command)
- *   FEATURE_TELEMETRY         +24-byte notify characteristic, 1 Hz
- *   FEATURE_IMU_STREAM        +14-byte notify characteristic, ~10 Hz
- *   FEATURE_TAP_DETECTION     LSM6DS3 hardware tap engine → L/R clicks
- *   FEATURE_TEMP_COMPENSATION Gyro drift correction by temperature delta
- *   FEATURE_AUTO_RECAL        Recalibrate after AUTO_RECAL_MS idle
- *   FEATURE_BATTERY_MONITOR   ADC battery read + BLE Battery Service
- *   FEATURE_BOOT_LOOP_DETECT  .noinit crash counter → safe mode
- *
  * Dependencies:
  *   FEATURE_TELEMETRY  requires FEATURE_CONFIG_SERVICE
  *   FEATURE_IMU_STREAM requires FEATURE_CONFIG_SERVICE
@@ -38,25 +23,26 @@
 #include <Adafruit_LittleFS.h>
 #include <InternalFileSystem.h>
 #include "Wire.h"
+#include "sleep.h"
 
-// ─── Boot-loop detection ──────────────────────────────────────────────────────
+// Boot-loop detection 
 #ifdef FEATURE_BOOT_LOOP_DETECT
   static uint32_t __attribute__((section(".noinit"))) bootCount;
   static uint32_t __attribute__((section(".noinit"))) bootMagic;
 #endif
 
-// ─── BLE Standard Services ────────────────────────────────────────────────────
+// BLE Standard Services 
 BLEDis         bledis;
 BLEHidAdafruit blehid;
 #ifdef FEATURE_BATTERY_MONITOR
   BLEBas blebas;
 #endif
 
-// ─── Persistence ──────────────────────────────────────────────────────────────
+// Persistence 
 using namespace Adafruit_LittleFS_Namespace;
 File cfgFile(InternalFS);
 
-// ─── Config definitions ───────────────────────────────────────────────────────
+// Config definitions 
 Config cfg;
 const Config CFG_DEFAULTS = {
   CONFIG_MAGIC, 600.0f, 0.060f, 0.08f, CURVE_LINEAR, 0x00, CHARGE_SLOW,
@@ -65,12 +51,12 @@ const Config CFG_DEFAULTS = {
   /*btnLeftPin=*/BTN_PIN_NONE, /*btnRightPin=*/BTN_PIN_NONE, /*btnMiddlePin=*/BTN_PIN_NONE
 };
 
-// ─── Telemetry definition ─────────────────────────────────────────────────────
+// Telemetry definition 
 #ifdef FEATURE_TELEMETRY
 TelemetryPacket telem = {};
 #endif
 
-// ─── Tuning constants ─────────────────────────────────────────────────────────
+// Tuning constants 
 const float ALPHA              = 0.96f;
 const int   LOOP_RATE_MS       = 10;
 const int   BIAS_SAMPLES       = 200;
@@ -96,7 +82,7 @@ const float BATT_CRITICAL                = 3.10f;
   const unsigned long AUTO_RECAL_MS = 5UL * 60UL * 1000UL;
 #endif
 
-// ─── Global state definitions ─────────────────────────────────────────────────
+// Global state definitions 
 float angleX = 0, angleY = 0;
 float accumX = 0, accumY = 0;
 // Low-pass filtered gravity estimate in device frame (for roll-independent axis projection)
@@ -131,10 +117,7 @@ uint32_t loopStalls = 0;          // loop iterations where dt > 20ms (behind sch
 bool pendingCal   = false;
 bool pendingReset = false;
 
-// ── Jerk-based shock detection — freeze cursor during tap impacts ────────────
+// Jerk-based shock detection - freeze cursor during tap impacts, doesn't work well yet!
-// Jerk = da/dt (rate of change of acceleration).  Normal mouse rotation produces
-// smooth accel changes (low jerk); a tap is a sharp impulse (very high jerk).
-// This cleanly separates taps from any intentional motion regardless of speed.
 unsigned long shockFreezeUntil = 0;
 float prevAx = 0, prevAy = 0, prevAz = 0;     // previous frame's accel for Δa
 const unsigned long SHOCK_FREEZE_MS = 80;       // hold freeze after last spike
@@ -160,7 +143,7 @@ unsigned long bootStartMs   = 0;
 bool safeMode         = false;
 bool bootCountCleared = false;
 
-// ─── Advertising ─────────────────────────────────────────────────────────────
+// Advertising 
 static void startAdvertising() {
   Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
   Bluefruit.Advertising.addTxPower();
@@ -176,7 +159,7 @@ static void startAdvertising() {
   Bluefruit.Advertising.start(0);
 }
 
-// ─── Setup ────────────────────────────────────────────────────────────────────
+// Setup 
 void setup() {
   Serial.begin(115200);
   unsigned long serialWait = millis();
@@ -187,14 +170,14 @@ void setup() {
   pinMode(LED_GREEN, OUTPUT); digitalWrite(LED_GREEN, HIGH);
   pinMode(LED_BLUE,  OUTPUT); digitalWrite(LED_BLUE,  HIGH);
 
-  // ── Boot-loop detection ───────────────────────────────────────────────────
+  // Boot-loop detection 
   #ifdef FEATURE_BOOT_LOOP_DETECT
     if (bootMagic != 0xCAFEBABE) { bootMagic = 0xCAFEBABE; bootCount = 0; }
     bootCount++;
     Serial.print("[BOOT] count="); Serial.println(bootCount);
     if (bootCount >= 3) {
       bootCount = 0; safeMode = true;
-      Serial.println("[BOOT] Boot loop — safe mode (no config service)");
+      Serial.println("[BOOT] Boot loop - safe mode (no config service)");
       InternalFS.begin(); InternalFS.remove(CONFIG_FILENAME);
       for (int i=0; i<3; i++) { digitalWrite(LED_RED,LOW); delay(150); digitalWrite(LED_RED,HIGH); delay(150); }  // fault: red
     }
@@ -213,7 +196,7 @@ void setup() {
   Bluefruit.begin(1, 0);
   Bluefruit.setTxPower(4);
   Bluefruit.setName(safeMode ? "IMU Mouse (safe)" : "IMU Mouse");
-  Bluefruit.Periph.setConnInterval(16, 32);  // 20-40ms — wider interval reduces SoftDevice TX stalls
+  Bluefruit.Periph.setConnInterval(16, 32);  // 20-40ms - wider interval reduces SoftDevice TX stalls
 
   Wire1.begin();  // LSM6DS3 is on internal I2C bus (Wire1), must init before imu.begin()
   if (imu.begin() != 0) {
@@ -241,6 +224,8 @@ void setup() {
   // Seed previous-accel for jerk detection so first frame doesn't spike
   prevAx = imu.readFloatAccelX(); prevAy = imu.readFloatAccelY(); prevAz = imu.readFloatAccelZ();
 
+  sleepManagerInit();
+
   bledis.setManufacturer("Seeed Studio");
   bledis.setModel("XIAO nRF52840 Sense");
   bledis.begin();
@@ -261,7 +246,7 @@ void setup() {
   #endif
 
   startAdvertising();
-  Serial.print("[OK] Advertising — features:");
+  Serial.print("[OK] Advertising - features:");
   #ifdef FEATURE_CONFIG_SERVICE
     Serial.print(" CFG");
   #endif
@@ -289,13 +274,14 @@ void setup() {
   #ifdef FEATURE_PHYSICAL_BUTTONS
     Serial.print(" PHYSBTN");
   #endif
+  Serial.print(" SLEEP");
   Serial.println();
 
   bootStartMs = millis();
   lastTime = lastBattTime = lastHeartbeat = lastTelemetry = millis();
 }
 
-// ─── Loop ─────────────────────────────────────────────────────────────────────
+// Loop 
 void loop() {
   unsigned long now = millis();
 
@@ -303,7 +289,7 @@ void loop() {
   #ifdef FEATURE_BOOT_LOOP_DETECT
     if (!bootCountCleared && (now - bootStartMs >= BOOT_SAFE_MS)) {
       bootCount = 0; bootCountCleared = true;
-      Serial.println("[BOOT] Stable — counter cleared");
+      Serial.println("[BOOT] Stable - counter cleared");
     }
   #endif
 
@@ -335,6 +321,11 @@ void loop() {
   #ifdef FEATURE_PHYSICAL_BUTTONS
     processPhysicalButtons();
   #endif
+  {
+    bool idle_for_sleep = (sleepStage == SLEEP_IMU_LP) ? true
+                          : (idleFrames >= IDLE_FRAMES);
+    if (sleepManagerUpdate(now, idle_for_sleep, Bluefruit.connected())) return;
+  }
 
   if (now - lastTime < (unsigned long)LOOP_RATE_MS) return;
   float dt = (now - lastTime) / 1000.0f;
@@ -352,7 +343,7 @@ void loop() {
     }
   #endif
 
-  // Gyro reads with optional temperature compensation
+  // Gyro reads with optional temperature compensation.
   float correction = 0.0f;
   #ifdef FEATURE_TEMP_COMPENSATION
     if (cfg.featureFlags & FLAG_TEMP_COMP_ENABLED)
@@ -366,17 +357,14 @@ void loop() {
   float ay = imu.readFloatAccelY();
   float az = imu.readFloatAccelZ();
 
-  // ── Jerk-based shock detection — freeze cursor during tap impacts ────────
+  // Jerk-based shock detection - freeze cursor during tap impacts, doesn't work well yet
-  // Jerk = da/dt.  Normal rotation = smooth accel changes (low jerk);
-  // a tap is a sharp impulse (very high jerk).
   float jx = (ax - prevAx) / dt, jy = (ay - prevAy) / dt, jz = (az - prevAz) / dt;
   float jerkSq = jx*jx + jy*jy + jz*jz;
   prevAx = ax; prevAy = ay; prevAz = az;
   bool shocked = cfg.tapFreezeEnabled && ((jerkSq > cfg.jerkThreshold) || (now < shockFreezeUntil));
   if (cfg.tapFreezeEnabled && jerkSq > cfg.jerkThreshold) shockFreezeUntil = now + SHOCK_FREEZE_MS;
 
-  // Complementary filter — gx=pitch axis, gz=yaw axis on this board layout
+  // Complementary filter
-  // During shock: gyro-only integration to avoid accel spike corrupting angles
   if (shocked) {
     angleX += gx * dt;
     angleY += gz * dt;
@@ -385,12 +373,7 @@ void loop() {
     angleY = ALPHA*(angleY + gz*dt) + (1.0f - ALPHA)*atan2f(ay, sqrtf(ax*ax + az*az));
   }
 
-  // ── Gravity-based axis decomposition ──────────────────────────────────────
+  // Gravity-based axis decomposition
-  // Low-pass filter accel to get a stable gravity estimate in device frame.
-  // This lets us project angular velocity onto world-aligned axes regardless
-  // of how the device is rolled.  Device forward (pointing) axis = X.
-  // Confirmed by diagnostics: GX=roll, GY=nod, GZ=pan in user's hold.
-  // Skip update during shock to protect the gravity estimate from tap spikes.
   const float GRAV_LP = 0.05f;
   if (!shocked) {
     gravX += GRAV_LP * (ax - gravX);
@@ -402,8 +385,6 @@ void loop() {
   if (gN < 0.3f) gN = 1.0f;
   float gnx = gravX/gN, gny = gravY/gN, gnz = gravZ/gN;
 
-  // Screen-right = cross(forward, up) = cross([1,0,0], [gnx,gny,gnz])
-  //              = [0, -gnz, gny]
   float ry = -gnz, rz = gny;
   float rN = sqrtf(ry*ry + rz*rz);
   if (rN < 0.01f) { ry = -1.0f; rz = 0.0f; rN = 1.0f; }
@@ -415,11 +396,9 @@ void loop() {
   float pitchRate = -(gy*ry + gz*rz);
 
   // Projected rates amplify residual gyro bias (especially GY drift on pitch axis).
-  // Use a wider dead zone for pitch to prevent constant cursor drift at rest.
   float fYaw   = (fabsf(yawRate)   > cfg.deadZone)       ? yawRate   : 0.0f;
   float fPitch = (fabsf(pitchRate) > cfg.deadZone * 3.0f) ? pitchRate : 0.0f;
 
-  // DIAG: print every 500ms to debug gravity projection — remove when confirmed
   #ifdef DEBUG
   { static unsigned long lastDiag = 0;
     if (now - lastDiag >= 500) { lastDiag = now;
@@ -438,7 +417,7 @@ void loop() {
 
   #ifdef FEATURE_AUTO_RECAL
     if ((cfg.featureFlags & FLAG_AUTO_RECAL_ENABLED) && idle && idleStartMs != 0 && (now - idleStartMs >= AUTO_RECAL_MS)) {
-      Serial.println("[AUTO-CAL] Long idle — recalibrating...");
+      Serial.println("[AUTO-CAL] Long idle - recalibrating...");
       idleStartMs = 0; calibrateGyroBias(); prevAx = imu.readFloatAccelX(); prevAy = imu.readFloatAccelY(); prevAz = imu.readFloatAccelZ(); return;
     }
   #endif
@@ -447,7 +426,7 @@ void loop() {
   uint8_t flags = 0;
 
   if (shocked) {
-    // Shock freeze — discard accumulated sub-pixel motion and suppress output
+    // Shock freeze - discard accumulated sub-pixel motion and suppress output
     accumX = accumY = 0.0f;
     flags |= 0x08;  // bit3 = shock freeze active
   } else if (idle) {
@@ -471,7 +450,7 @@ void loop() {
       lastImuStream = now;
 
       if (now < streamBackoffUntil) {
-        // Backing off — host TX buffer congested, skip to avoid 100ms block
+        // Backing off - host TX buffer congested, skip to avoid 100ms block
       } else {
         ImuPacket pkt;
         pkt.gyroX_mDPS = (int16_t)constrain(gx*(180.f/PI)*1000.f, -32000, 32000);
@@ -492,7 +471,7 @@ void loop() {
           if (streamConsecFails >= STREAM_BACKOFF_THRESH) {
             streamBackoffUntil = now + STREAM_BACKOFF_MS;
             streamConsecFails  = 0;
-            Serial.print("[STREAM] TX congested — backing off ");
+            Serial.print("[STREAM] TX congested - backing off ");
             Serial.print(STREAM_BACKOFF_MS); Serial.println("ms");
           }
         }
@@ -508,4 +487,4 @@ void loop() {
       }
     }
   #endif
-}
+}

source/sleep.cpp

@@ -0,0 +1,312 @@
+#include "sleep.h"
+#include "imu.h"       // config.h REG_* macros
+#include <bluefruit.h> // sd_app_evt_wait()
+#include "Wire.h"
+
+// Registers not in config.h 
+#define SLP_CTRL2_G      0x11
+#define SLP_CTRL6_C      0x15
+#define SLP_CTRL7_G      0x16
+#define SLP_WAKE_UP_DUR  0x5C
+#define SLP_WAKE_UP_SRC  0x1B
+
+#define LSM_ADDR     0x6A
+
+#define XL_ODR_26HZ  0x20
+#define XL_ODR_416HZ 0x60
+#define G_ODR_416HZ  0x60
+
+// Module state 
+volatile SleepStage sleepStage  = SLEEP_AWAKE;
+volatile bool       imuWakeFlag = false;
+
+static unsigned long idleEnteredMs  = 0;  // when motion pipeline first went idle
+static unsigned long wakeSettleMs   = 0;  // when sleepManagerWakeIMU() was called
+static unsigned long lpEnteredMs    = 0;  // when IMU LP was entered (for recal decision)
+
+static bool          wasIdle        = false;
+static uint8_t       savedCtrl1XL   = XL_ODR_416HZ;
+static uint8_t       savedCtrl2G    = G_ODR_416HZ;
+static volatile bool pendingWakeSettle = false;  // always set on wake - 120ms blackout
+static volatile bool pendingWakeRecal  = false;  // set only when recal is also needed
+
+// Only force recalibration after waking from deep sleep, or after the gyro
+// has been off long enough for thermal drift to matter (~5 minutes).
+static constexpr unsigned long RECAL_AFTER_LP_MS = 5UL * 60UL * 1000UL;
+
+// I2C helpers - Wire1 at 0x6A (SA0 LOW on XIAO nRF52840 Sense) 
+static uint8_t lsmRead(uint8_t reg) {
+  Wire1.beginTransmission(LSM_ADDR);
+  Wire1.write(reg);
+  Wire1.endTransmission(false);
+  Wire1.requestFrom(LSM_ADDR, (uint8_t)1);
+  return Wire1.available() ? Wire1.read() : 0xFF;
+}
+
+static void lsmWrite(uint8_t reg, uint8_t val) {
+  Wire1.beginTransmission(LSM_ADDR);
+  Wire1.write(reg);
+  Wire1.write(val);
+  Wire1.endTransmission();
+}
+
+// ISR 
+static void imuInt1ISR() {
+  imuWakeFlag = true;
+}
+
+// Arm wakeup interrupt 
+static void armWakeupInterrupt() {
+  lsmWrite(SLP_WAKE_UP_DUR, (uint8_t)((SLEEP_WAKEUP_DUR & 0x03) << 4));
+
+  // Preserve bit7 (tap single/double enable)
+  uint8_t wuth = lsmRead(REG_WAKE_UP_THS);
+  wuth = (wuth & 0xC0) | (SLEEP_WAKEUP_THS & 0x3F);
+  lsmWrite(REG_WAKE_UP_THS, wuth);
+
+  // INTERRUPTS_ENABLE=1, SLOPE_FDS=0 (HP filter is gated in LP - must be 0)
+  uint8_t tcfg = lsmRead(REG_TAP_CFG);
+  tcfg |=  (1 << 7);
+  tcfg &= ~(1 << 4);
+  lsmWrite(REG_TAP_CFG, tcfg);
+
+  uint8_t md1 = lsmRead(REG_MD1_CFG);
+  md1 |= (1 << 5);
+  lsmWrite(REG_MD1_CFG, md1);
+
+  // Clear any stale latch BEFORE re-arming the edge interrupt.
+  (void)lsmRead(SLP_WAKE_UP_SRC);
+  delay(2);
+
+  // Re-attach with RISING - guaranteed clean edge now that latch is cleared
+  detachInterrupt(digitalPinToInterrupt(IMU_INT1_PIN));
+  attachInterrupt(digitalPinToInterrupt(IMU_INT1_PIN), imuInt1ISR, RISING);
+  imuWakeFlag = false;
+
+#ifdef DEBUG
+  Serial.print("[SLEEP] armWakeup - TAP_CFG=0x"); Serial.print(lsmRead(REG_TAP_CFG), HEX);
+  Serial.print(" MD1_CFG=0x"); Serial.print(lsmRead(REG_MD1_CFG), HEX);
+  Serial.print(" WAKE_UP_THS=0x"); Serial.println(lsmRead(REG_WAKE_UP_THS), HEX);
+#endif
+}
+
+static void disarmWakeupInterrupt() {
+  // Restore SLOPE_FDS=1 for tap detection HP filter path
+  uint8_t tcfg = lsmRead(REG_TAP_CFG);
+  tcfg |= (1 << 4);
+  lsmWrite(REG_TAP_CFG, tcfg);
+
+  // Clear INT1_WU to stop wakeup engine driving INT1 at full rate
+  uint8_t md1 = lsmRead(REG_MD1_CFG);
+  md1 &= ~(1 << 5);
+  lsmWrite(REG_MD1_CFG, md1);
+}
+
+// Enter IMU LP 
+static void enterImuLP() {
+  if (sleepStage >= SLEEP_IMU_LP) return;
+
+  savedCtrl1XL = lsmRead(REG_CTRL1_XL);
+  savedCtrl2G  = lsmRead(SLP_CTRL2_G);
+
+  lsmWrite(SLP_CTRL2_G,  savedCtrl2G & 0x0F);                      // gyro off
+  lsmWrite(REG_CTRL1_XL, (savedCtrl1XL & 0x0F) | XL_ODR_26HZ);    // accel 26 Hz
+  lsmWrite(SLP_CTRL6_C,  lsmRead(SLP_CTRL6_C) | (1 << 4));         // XL_HM_MODE=1
+  lsmWrite(SLP_CTRL7_G,  lsmRead(SLP_CTRL7_G) | (1 << 7));         // G_HM_MODE=1
+
+  armWakeupInterrupt();
+
+  lpEnteredMs = millis();
+  sleepStage = SLEEP_IMU_LP;
+  Serial.print("[SLEEP] IMU LP entered - idle for ");
+  Serial.print((millis() - idleEnteredMs) / 1000); Serial.println("s");
+
+#ifdef DEBUG
+  Serial.print("[SLEEP] CTRL1_XL=0x"); Serial.print(lsmRead(REG_CTRL1_XL), HEX);
+  Serial.print(" CTRL2_G=0x");  Serial.print(lsmRead(SLP_CTRL2_G), HEX);
+  Serial.print(" CTRL6_C=0x");  Serial.print(lsmRead(SLP_CTRL6_C), HEX);
+  Serial.print(" CTRL7_G=0x");  Serial.println(lsmRead(SLP_CTRL7_G), HEX);
+  Serial.print("[SLEEP] TAP_CFG=0x");    Serial.print(lsmRead(REG_TAP_CFG), HEX);
+  Serial.print(" MD1_CFG=0x");          Serial.print(lsmRead(REG_MD1_CFG), HEX);
+  Serial.print(" WAKE_UP_THS=0x");      Serial.print(lsmRead(REG_WAKE_UP_THS), HEX);
+  Serial.print(" WAKE_UP_DUR=0x");      Serial.println(lsmRead(SLP_WAKE_UP_DUR), HEX);
+#endif
+}
+
+// Enter deep sleep 
+static void enterDeepSleep() {
+  if (sleepStage >= SLEEP_DEEP) return;
+  if (sleepStage < SLEEP_IMU_LP) enterImuLP();
+
+  sleepStage = SLEEP_DEEP;
+  Serial.println("[SLEEP] Deep sleep - WFE on INT1");
+  Serial.flush();
+
+  digitalWrite(LED_RED, LOW); delay(80); digitalWrite(LED_RED, HIGH);
+
+  while (!imuWakeFlag) {
+    (void)lsmRead(SLP_WAKE_UP_SRC);
+    sd_app_evt_wait();
+  }
+}
+
+// Public: wake 
+void sleepManagerWakeIMU() {
+  (void)lsmRead(SLP_WAKE_UP_SRC);
+
+  lsmWrite(SLP_CTRL6_C, lsmRead(SLP_CTRL6_C) & ~(1 << 4));
+  lsmWrite(SLP_CTRL7_G, lsmRead(SLP_CTRL7_G) & ~(1 << 7));
+  lsmWrite(REG_CTRL1_XL, savedCtrl1XL);
+  lsmWrite(SLP_CTRL2_G,  savedCtrl2G);
+
+  disarmWakeupInterrupt();
+
+  // Only recalibrate if gyro was off long enough for thermal drift to accumulate,
+  // or if waking from full deep sleep. Short LP naps reuse the existing bias.
+  unsigned long lpDuration = millis() - lpEnteredMs;
+  bool needsRecal = (sleepStage == SLEEP_DEEP) || (lpDuration >= RECAL_AFTER_LP_MS);
+
+  wakeSettleMs      = millis();
+  pendingWakeSettle = true;          // always block output for 120ms
+  pendingWakeRecal  = needsRecal;    // additionally recalibrate if needed
+
+  wasIdle       = false;
+  idleEnteredMs = 0;
+  lpEnteredMs   = 0;
+
+  // Reset motion filter state to prevent a cursor jump on the first frame.
+  // After sleep: angleX/Y are stale, gravX/Y/Z drifted, accumX/Y is dirty,
+  // and lastTime is old so dt would be huge on the first loop iteration.
+  // Zeroing these here means the first frame integrates 0 motion cleanly.
+  extern float angleX, angleY;
+  extern float accumX, accumY;
+  extern float gravX, gravY, gravZ;
+  extern float prevAx, prevAy, prevAz;
+  extern unsigned long lastTime;
+  angleX = angleY = 0.0f;
+  accumX = accumY = 0.0f;
+  // Reseed gravity from current accel so projection is correct immediately.
+  // Can't call imu.readFloat* here (gyro not fully settled), but accel is
+  // already running - read it directly via Wire1.
+  // Simpler: just reset to neutral [0,0,1] and let the LP filter converge
+  // over the first ~20 frames (200 ms) of real use.
+  gravX = 0.0f; gravY = 0.0f; gravZ = 1.0f;
+  prevAx = 0.0f; prevAy = 0.0f; prevAz = 0.0f;
+  // Set lastTime to now so the first dt = 0 rather than (now - sleepEntryTime)
+  lastTime = millis();
+
+  sleepStage = SLEEP_AWAKE;
+  if (needsRecal)
+    Serial.println("[SLEEP] Awake - gyro settling, recal needed");
+  else
+    Serial.println("[SLEEP] Awake - short LP, reusing existing bias");
+}
+
+// Public: init 
+void sleepManagerInit() {
+  pinMode(IMU_INT1_PIN, INPUT);
+  attachInterrupt(digitalPinToInterrupt(IMU_INT1_PIN), imuInt1ISR, RISING);
+
+  // Sanity check: WHO_AM_I should return 0x6A for LSM6DS3
+  uint8_t whoami = imuReadReg(0x0F);
+  Serial.print("[SLEEP] WHO_AM_I=0x"); Serial.print(whoami, HEX);
+  if (whoami == 0x6A) Serial.println(" (OK)");
+  else                Serial.println(" (WRONG - I2C not working, sleep disabled)");
+
+  if (whoami != 0x6A) return;  // don't arm anything if we can't talk to the IMU
+
+  Serial.print("[SLEEP] Init - INT1 pin="); Serial.print(IMU_INT1_PIN);
+  Serial.print(", WU_THS="); Serial.print(SLEEP_WAKEUP_THS);
+  Serial.print(" (~"); Serial.print(SLEEP_WAKEUP_THS * 7.8f, 0); Serial.print(" mg)");
+  Serial.print(", IMU_LP after "); Serial.print(SLEEP_IMU_IDLE_MS / 1000); Serial.print("s");
+  Serial.print(", deep after ");   Serial.print(SLEEP_DEEP_IDLE_MS / 1000); Serial.println("s");
+}
+
+// Public: per-loop update 
+// Must be called AFTER idleFrames/idle is updated by the motion pipeline.
+// Returns true → caller must skip IMU reads this iteration.
+bool sleepManagerUpdate(unsigned long nowMs, bool idle, bool bleConnected) {
+
+  // ISR wakeup 
+  if (imuWakeFlag) {
+    imuWakeFlag = false;
+    Serial.print("[SLEEP] INT1 fired - stage="); Serial.println((int)sleepStage);
+    if (sleepStage == SLEEP_DEEP || sleepStage == SLEEP_IMU_LP) {
+      sleepManagerWakeIMU();
+    } else {
+      (void)lsmRead(SLP_WAKE_UP_SRC);  // normal-mode edge, clear latch only
+    }
+  }
+
+  // Gyro settling after wake 
+  if (pendingWakeRecal) {
+    if (nowMs - wakeSettleMs >= 120) {
+      pendingWakeRecal = false;
+      wakeSettleMs     = 0;
+      extern void calibrateGyroBias();
+      calibrateGyroBias();
+      Serial.println("[SLEEP] Post-wake recal done");
+    }
+    return true;
+  }
+
+  // IMU_LP path 
+  // main.cpp returns early when we return true, so idleFrames never increments
+  // and the motion pipeline's `idle` flag is stale. Use our own idleEnteredMs
+  // (captured before LP entry) to drive the deep-sleep countdown independently.
+  if (sleepStage == SLEEP_IMU_LP) {
+    // Periodic log: confirms loop is running, shows live INT1 pin level and
+    // WAKE_UP_SRC register. If INT1_pin never goes high after movement, the
+    // wakeup engine is not generating an interrupt - check register values.
+    static unsigned long lastLpLog = 0;
+    if (nowMs - lastLpLog >= 5000) {
+      lastLpLog = nowMs;
+      unsigned long lpSecs = idleEnteredMs ? (nowMs - idleEnteredMs) / 1000 : 0;
+      Serial.print("[SLEEP] LP tick - idle="); Serial.print(lpSecs);
+      Serial.print("s INT1="); Serial.print(digitalRead(IMU_INT1_PIN));
+      Serial.print(" WAKE_UP_SRC=0x"); Serial.println(lsmRead(SLP_WAKE_UP_SRC), HEX);
+    }
+    if (!bleConnected && idleEnteredMs != 0
+        && (nowMs - idleEnteredMs >= SLEEP_DEEP_IDLE_MS))
+    {
+      Serial.println("[SLEEP] Deep sleep threshold reached");
+      enterDeepSleep();
+    }
+    return true;
+  }
+
+  // AWAKE path 
+  if (!idle) {
+    if (wasIdle) {
+      Serial.println("[SLEEP] Motion - idle timer reset");
+    }
+    wasIdle       = false;
+    idleEnteredMs = 0;
+    return false;
+  }
+
+  if (!wasIdle) {
+    wasIdle       = true;
+    idleEnteredMs = nowMs;
+    Serial.println("[SLEEP] Idle started");
+  }
+
+  unsigned long idleElapsed = nowMs - idleEnteredMs;
+
+  // Progress report every 5 s while waiting for LP threshold
+  #ifdef DEBUG
+  { static unsigned long lastReport = 0;
+    if (nowMs - lastReport >= 5000) { lastReport = nowMs;
+      Serial.print("[SLEEP] idle="); Serial.print(idleElapsed/1000);
+      Serial.print("s / LP@"); Serial.print(SLEEP_IMU_IDLE_MS/1000); Serial.println("s");
+    }
+  }
+  #endif
+
+  if (idleElapsed >= SLEEP_IMU_IDLE_MS) {
+    enterImuLP();
+    return true;
+  }
+
+  return false;
+}

source/sleep.h

@@ -0,0 +1,39 @@
+#pragma once
+#include <Arduino.h>
+
+// Tuning 
+#ifndef SLEEP_IMU_IDLE_MS
+  #define SLEEP_IMU_IDLE_MS   (10UL * 1000UL)   // 10 s  → gyro off, accel LP
+#endif
+#ifndef SLEEP_DEEP_IDLE_MS
+  #define SLEEP_DEEP_IDLE_MS  (60UL * 1000UL)   // 60 s  → system deep sleep (no-BLE only)
+#endif
+
+// LSM6DS3 wakeup threshold: 1 LSB = 7.8 mg at ±2 g FS (±2g range).
+#ifndef SLEEP_WAKEUP_THS
+  #define SLEEP_WAKEUP_THS   16    // 0–63
+#endif
+
+// Number of consecutive 26 Hz samples that must exceed the threshold.
+#ifndef SLEEP_WAKEUP_DUR
+  #define SLEEP_WAKEUP_DUR   2    // 0–3
+#endif
+
+// GPIO pin connected to LSM6DS3 INT1.
+#ifndef IMU_INT1_PIN
+  #define IMU_INT1_PIN  PIN_LSM6DS3TR_C_INT1
+#endif
+
+// Public state (read-only from main.cpp) 
+enum SleepStage : uint8_t {
+  SLEEP_AWAKE  = 0,   // normal full-rate operation
+  SLEEP_IMU_LP = 1,   // gyro off, accel LP - nRF awake
+  SLEEP_DEEP   = 2,   // system WFE - BLE disconnected only
+};
+
+extern volatile SleepStage sleepStage;
+extern volatile bool       imuWakeFlag;
+
+void sleepManagerInit();
+bool sleepManagerUpdate(unsigned long nowMs, bool idle, bool bleConnected);
+void sleepManagerWakeIMU();

source/tap.cpp

@@ -6,12 +6,12 @@
 
 extern BLEHidAdafruit blehid;
 
-// ─── Tap detection setup ──────────────────────────────────────────────────────
+// Tap detection setup 
 // REG_TAP_THS_6D bits[4:0] = tapThreshold (1–31); 1 LSB = FS/32 = 62.5 mg at ±2g.
 // REG_INT_DUR2 at ODR=416 Hz:
-//   SHOCK[7:6] = 2 → 38 ms max tap duration
+//  SHOCK[7:6] = 2 → 38 ms max tap duration
-//   QUIET[5:4] = 2 → 19 ms refractory after tap
+//  QUIET[5:4] = 2 → 19 ms refractory after tap
-//   DUR[3:0]   = 6 → 115 ms max inter-tap window for double detection
+//  DUR[3:0]   = 6 → 115 ms max inter-tap window for double detection
 void applyTapThreshold() {
   uint8_t thr = cfg.tapThreshold;
   if (thr < 1)  thr = 1;
@@ -30,18 +30,7 @@ void setupTapDetection() {
   Serial.print(" (~"); Serial.print(cfg.tapThreshold * 62.5f, 0); Serial.println(" mg)");
 }
 
-// ─── Tap processing ───────────────────────────────────────────────────────────
+// Tap processing 
-// Only double-tap is mapped to an action. Single-tap is ignored (it always fires
-// before the double is confirmed and cannot be reliably disambiguated on this
-// hardware without an unacceptable latency penalty).
-//
-// The LSM6DS3 sets SINGLE_TAP immediately on first contact — we wait until
-// DOUBLE_TAP is set (within the hardware DUR window of 115 ms) before acting.
-// An additional TAP_CONFIRM_MS guard ensures the TAP_SRC register has settled.
-//
-// IMPORTANT: call mouseButtonPress(bitmask) — single arg only. The two-arg
-// overload takes (conn_hdl, buttons) and sends the wrong button value.
-
 static enum { TAP_IDLE, TAP_PENDING, TAP_EXECUTING } tapState = TAP_IDLE;
 static unsigned long tapPendingMs  = 0;
 static uint8_t       pendingButton = 0;   // 0 = key action pending
@@ -83,7 +72,7 @@ static void fireTapAction(unsigned long now) {
 }
 
 void processTaps(unsigned long now) {
-  // ── Release ───────────────────────────────────────────────────────────────
+  // Release 
   if (tapState == TAP_EXECUTING) {
     if (now - clickDownMs >= CLICK_HOLD_MS) {
       if (pendingButton) {
@@ -99,7 +88,7 @@ void processTaps(unsigned long now) {
     return;
   }
 
-  // ── Poll TAP_SRC ──────────────────────────────────────────────────────────
+  // Poll TAP_SRC 
   uint8_t tapSrc = imuReadReg(REG_TAP_SRC);
   bool tapIA     = !!(tapSrc & 0x40);
   bool doubleTap = !!(tapSrc & 0x10);

web/app.js

@@ -1,4 +1,4 @@
-// ── UUIDs ────────────────────────────────────────────────────────────────────
+// UUIDs 
 // v3.3: 4 characteristics instead of 10
 const SVC_UUID = '00001234-0000-1000-8000-00805f9b34fb';
 const CHR = {
@@ -25,11 +25,11 @@ let device=null, server=null, chars={}, userDisconnected=false;
 let currentChargeStatus=0, currentBattPct=null, currentBattVoltage=null;
 let advancedMode = localStorage.getItem('advanced') === 'true';
 
-// ── GATT write queue (prevents "operation already in progress") ───────────────
+// GATT write queue (prevents "operation already in progress") 
 // Serialises all GATT writes. Features:
-//   • Per-operation 3s timeout — hangs don't block the queue forever
+//  • Per-operation 3s timeout - hangs don't block the queue forever
-//   • Max depth of 2 pending ops — drops excess writes when device goes silent
+//  • Max depth of 2 pending ops - drops excess writes when device goes silent
-//   • gattQueueReset() flushes on disconnect so a reconnect starts clean
+//  • gattQueueReset() flushes on disconnect so a reconnect starts clean
 const GATT_TIMEOUT_MS = 3000;
 const GATT_MAX_DEPTH  = 2;
 let _gattQueue = Promise.resolve();
@@ -45,7 +45,7 @@ function _withTimeout(promise, ms) {
 
 function _enqueue(fn) {
   if (_gattDepth >= GATT_MAX_DEPTH) {
-    return Promise.reject(new Error('GATT queue full — device unreachable?'));
+    return Promise.reject(new Error('GATT queue full - device unreachable?'));
   }
   _gattDepth++;
   const p = _gattQueue.then(() => _withTimeout(fn(), GATT_TIMEOUT_MS));
@@ -62,7 +62,7 @@ function gattQueueReset() {
   _gattDepth = 0;
 }
 
-// ── Logging ──────────────────────────────────────────────────────────────────
+// Logging 
 (function() {
   const _methods = { log: '', warn: 'warn', error: 'err' };
   for (const [method, type] of Object.entries(_methods)) {
@@ -85,7 +85,7 @@ function log(msg, type='') {
 const p2=n=>String(n).padStart(2,'0'), p3=n=>String(n).padStart(3,'0');
 function cssVar(n) { return getComputedStyle(document.documentElement).getPropertyValue(n).trim(); }
 
-// ── Connection ───────────────────────────────────────────────────────────────
+// Connection 
 async function doConnect() {
   if (!navigator.bluetooth) { log('Web Bluetooth not supported.','err'); return; }
   userDisconnected = false;
@@ -131,27 +131,27 @@ async function discoverServices() {
     // Read firmware git hash and check against web build hash
     await checkHashMatch();
 
-    // Telemetry notify (1 Hz) — also carries chargeStatus
+    // Telemetry notify (1 Hz) - also carries chargeStatus
     chars.telemetry.addEventListener('characteristicvaluechanged', e => parseTelemetry(e.target.value));
     await chars.telemetry.startNotifications();
     // Initial read so values show immediately. Also force updateChargeUI() here
     // because parseTelemetry() only calls it on a *change*, and currentChargeStatus
-    // starts at 0 (discharging) — so a discharging device would never trigger the
+    // starts at 0 (discharging) - so a discharging device would never trigger the
     // update and ciStatus would stay at '--'.
     parseTelemetry(await chars.telemetry.readValue());
     updateChargeUI();
 
-    // IMU stream — subscribed on demand via play button
+    // IMU stream - subscribed on demand via play button
     chars.imuStream.addEventListener('characteristicvaluechanged', e => parseImuStream(e.target.value));
 
     log('Config service ready (4 chars)','ok');
   } catch(e) {
     log(`Service discovery failed: ${e.message}`,'err');
     // Safe mode device might not have config service
-    if (e.message.includes('not found')) log('Device may be in safe mode — basic mouse only','warn');
+    if (e.message.includes('not found')) log('Device may be in safe mode - basic mouse only','warn');
   }
 
-  // Battery service (standard — always present)
+  // Battery service (standard - always present)
   try {
     const bsvc = await server.getPrimaryService('battery_service');
     const bch  = await bsvc.getCharacteristic('battery_level');
@@ -167,7 +167,7 @@ async function discoverServices() {
   } catch(e) { log('Battery service unavailable','warn'); }
 }
 
-// ── Firmware / web hash mismatch banner ──────────────────────────────────────
+// Firmware / web hash mismatch banner 
 async function checkHashMatch() {
   const banner = document.getElementById('hashMismatchBanner');
   if (!chars.gitHash) return;
@@ -199,20 +199,20 @@ async function checkHashMatch() {
   ].join(';');
   banner.innerHTML =
     `<span style="font-size:14px">⚠</span>` +
-    `<span>FIRMWARE / WEB MISMATCH — ` +
+    `<span>FIRMWARE / WEB MISMATCH - ` +
-    `firmware <b>${fwHash}</b> · web <b>${webHash}</b> — ` +
+    `firmware <b>${fwHash}</b> · web <b>${webHash}</b> - ` +
     `flash firmware or reload the page after a <code>pio run</code></span>` +
     `<button onclick="document.getElementById('hashMismatchBanner').style.display='none'" ` +
     `style="margin-left:8px;background:none;border:1px solid #c04040;color:#ffd0d0;` +
     `cursor:pointer;padding:2px 8px;font-family:var(--mono);font-size:10px">✕</button>`;
 }
 
-// ── ConfigBlob read / write ──────────────────────────────────────────────────
+// ConfigBlob read / write 
 // ConfigBlob layout (25 bytes LE):
-//   float sensitivity [0], float deadZone [4], float accelStrength [8]
+//  float sensitivity [0], float deadZone [4], float accelStrength [8]
-//   uint8 curve [12], uint8 axisFlip [13], uint8 chargeMode [14]
+//  uint8 curve [12], uint8 axisFlip [13], uint8 chargeMode [14]
-//   uint8 tapThreshold [15], uint8 tapAction [16], uint8 tapKey [17], uint8 tapMod [18], uint8 tapFreezeEnabled [19]
+//  uint8 tapThreshold [15], uint8 tapAction [16], uint8 tapKey [17], uint8 tapMod [18], uint8 tapFreezeEnabled [19]
-//   float jerkThreshold [20], uint8 featureFlags [24]
+//  float jerkThreshold [20], uint8 featureFlags [24]
 
 async function readConfigBlob() {
   if (!chars.configBlob) return;
@@ -238,7 +238,7 @@ async function readConfigBlob() {
     if (view.byteLength >= 25) {
       config.featureFlags = view.getUint8(24);
     } else {
-      config.featureFlags = FLAG_ALL_DEFAULT;  // old firmware — assume all on
+      config.featureFlags = FLAG_ALL_DEFAULT;  // old firmware - assume all on
     }
     if (view.byteLength >= 28) {
       config.btnLeftPin   = view.getUint8(25);
@@ -248,7 +248,7 @@ async function readConfigBlob() {
       config.btnLeftPin = config.btnRightPin = config.btnMiddlePin = 0xFF;  // disabled
     }
     applyConfigToUI();
-    log(`Config loaded — sens=${config.sensitivity.toFixed(0)} dz=${config.deadZone.toFixed(3)} tapThr=${config.tapThreshold}`,'ok');
+    log(`Config loaded - sens=${config.sensitivity.toFixed(0)} dz=${config.deadZone.toFixed(3)} tapThr=${config.tapThreshold}`,'ok');
   } catch(e) { log(`Config read error: ${e.message}`,'err'); }
 }
 
@@ -284,7 +284,7 @@ function applyConfigToUI() {
   updatePinDiagram();
 }
 
-// ── XIAO pin diagram ──────────────────────────────────────────────────────────
+// XIAO pin diagram 
 function updatePinDiagram() {
   const st = getComputedStyle(document.documentElement);
   const COL_L = st.getPropertyValue('--ok').trim();
@@ -362,11 +362,11 @@ async function _doWriteConfigBlob() {
 
   try {
     await gattWrite(chars.configBlob, buf);
-    log(`Config written — sens=${config.sensitivity.toFixed(0)} tapThr=${config.tapThreshold} tapAction=${config.tapAction}`,'ok');
+    log(`Config written - sens=${config.sensitivity.toFixed(0)} tapThr=${config.tapThreshold} tapAction=${config.tapAction}`,'ok');
   } catch(e) { log(`Config write failed: ${e.message}`,'err'); }
 }
 
-// ── Individual control handlers ───────────────────────────────────────────────
+// Individual control handlers 
 // These update the local config shadow then write the full blob
 
 function setCurve(val) {
@@ -397,7 +397,7 @@ function setChargeModeUI(val) {
 
 function onCapTapChange(enabled) {
   writeConfigBlob();
-  log('Tap detection ' + (enabled ? 'enabled' : 'disabled') + ' — restart device to apply', 'warn');
+  log('Tap detection ' + (enabled ? 'enabled' : 'disabled') + ' - restart device to apply', 'warn');
 }
 
 function onTapFreezeChange(enabled) {
@@ -430,7 +430,7 @@ function onTapKeyInput() {
 
 async function sendCalibrate() {
   if (!chars.command) return;
-  try { await gattCmd(chars.command, new Uint8Array([0x01])); log('Calibration sent — hold still!','warn'); }
+  try { await gattCmd(chars.command, new Uint8Array([0x01])); log('Calibration sent - hold still!','warn'); }
   catch(e) { log(`Calibrate failed: ${e.message}`,'err'); }
 }
 function confirmReset() { document.getElementById('overlay').classList.add('show'); }
@@ -444,22 +444,22 @@ async function doReset() {
   } catch(e) { log(`Reset failed: ${e.message}`,'err'); }
 }
 
-// ── Telemetry ────────────────────────────────────────────────────────────────
+// Telemetry 
-// TelemetryPacket (28 bytes LE — backwards compatible with 24-byte v3.3):
+// TelemetryPacket (28 bytes LE - backwards compatible with 24-byte v3.3):
-//   uint32 uptime [0], uint32 leftClicks [4], uint32 rightClicks [8]
+//  uint32 uptime [0], uint32 leftClicks [4], uint32 rightClicks [8]
-//   float  temp   [12], float biasRms    [16]
+//  float  temp   [12], float biasRms    [16]
-//   uint16 recalCount [20], uint8 chargeStatus [22], uint8 pad [23]
+//  uint16 recalCount [20], uint8 chargeStatus [22], uint8 pad [23]
-//   float  battVoltage [24]  (new in v3.4, absent on older firmware)
+//  float  battVoltage [24]  (new in v3.4, absent on older firmware)
 function parseTelemetry(dv) {
   let view;
   try {
     view = dv instanceof DataView ? new DataView(dv.buffer, dv.byteOffset, dv.byteLength) : new DataView(dv);
-  } catch(e) { log(`parseTelemetry: DataView wrap failed — ${e.message}`,'err'); return; }
+  } catch(e) { log(`parseTelemetry: DataView wrap failed - ${e.message}`,'err'); return; }
 
   if (view.byteLength < 24) {
     const bytes = new Uint8Array(view.buffer, view.byteOffset, view.byteLength);
     const hex = Array.from(bytes).map(b=>b.toString(16).padStart(2,'0')).join(' ');
-    log(`TELEM: expected 24-28B, got ${view.byteLength}B — MTU too small? raw: ${hex}`,'err');
+    log(`TELEM: expected 24-28B, got ${view.byteLength}B - MTU too small? raw: ${hex}`,'err');
     return;
   }
 
@@ -473,7 +473,7 @@ function parseTelemetry(dv) {
     recalCount  = view.getUint16(20, true);
     chargeStatus= view.getUint8(22);
     if (view.byteLength >= 28) battVoltage = view.getFloat32(24, true);
-  } catch(e) { log(`parseTelemetry: parse error at offset — ${e.message}`,'err'); return; }
+  } catch(e) { log(`parseTelemetry: parse error at offset - ${e.message}`,'err'); return; }
 
   document.getElementById('telTemp').textContent   = temp.toFixed(1)+'°';
   document.getElementById('telUptime').textContent = formatUptime(uptime);
@@ -504,7 +504,7 @@ function clearTelemetry() {
     document.getElementById(id).textContent='--');
 }
 
-// ── Battery & Charge UI ───────────────────────────────────────────────────────
+// Battery & Charge UI 
 function updateBatteryBar(pct, status) {
   document.getElementById('battBar').style.display='flex';
   document.getElementById('battPct').textContent=pct+'%';
@@ -528,7 +528,7 @@ function updateChargeUI() {
   if (currentBattPct!==null) updateBatteryBar(currentBattPct, currentChargeStatus);
 }
 
-// ── Advanced toggle ───────────────────────────────────────────────────────
+// Advanced toggle 
 function toggleAdvanced(on) {
   advancedMode = on;
   localStorage.setItem('advanced', on);
@@ -538,7 +538,7 @@ function toggleAdvanced(on) {
   document.getElementById('chargeInfo').style.gridTemplateColumns = on ? '1fr 1fr 1fr 1fr' : '1fr 1fr 1fr';
 }
 
-// ── IMU Debug Recorder ────────────────────────────────────────────────────────
+// IMU Debug Recorder 
 let debugModalOpen = false;
 let debugRecording = false;
 let debugBuffer = [];
@@ -631,7 +631,7 @@ function clearDebugRec() {
   document.getElementById('debugRecCount').textContent = '0 samples';
 }
 
-// ── Param display ─────────────────────────────────────────────────────────────
+// Param display 
 function updateDisplay(key, val) {
   const map = {
     sensitivity:  ['valSensitivity',  v=>parseFloat(v).toFixed(0)],
@@ -644,7 +644,7 @@ function updateDisplay(key, val) {
   document.getElementById(id).textContent = fmt(val);
 }
 
-// ── Status UI ────────────────────────────────────────────────────────────────
+// Status UI 
 function setStatus(state) {
   const pill=document.getElementById('statusPill');
   document.getElementById('statusText').textContent={connected:'CONNECTED',connecting:'CONNECTING…',disconnected:'DISCONNECTED'}[state];
@@ -673,7 +673,7 @@ function onDisconnected() {
   document.getElementById('badgeCharging').classList.remove('show');
   document.getElementById('badgeFull').classList.remove('show');
   imuSubscribed = false; vizPaused = true; vizUpdateIndicator(); streamDiagReset();
-  document.getElementById('orientLabel').textContent = '— not streaming —';
+  document.getElementById('orientLabel').textContent = '- not streaming -';
   document.getElementById('hashMismatchBanner').style.display = 'none';
   clearTelemetry();
   if (!userDisconnected && document.getElementById('autoReconnect').checked && savedDevice) {
@@ -695,11 +695,11 @@ function onDisconnected() {
   }
 }
 
-// ── IMU Stream + Visualiser ──────────────────────────────────────────────────
+// IMU Stream + Visualiser 
 // ImuPacket (14 bytes LE):
-//   int16 gyroX_mDPS [0], int16 gyroZ_mDPS [2]
+//  int16 gyroX_mDPS [0], int16 gyroZ_mDPS [2]
-//   int16 accelX_mg  [4], int16 accelY_mg  [6], int16 accelZ_mg [8]
+//  int16 accelX_mg  [4], int16 accelY_mg  [6], int16 accelZ_mg [8]
-//   int8  moveX [10], int8 moveY [11], uint8 flags [12], uint8 pad [13]
+//  int8  moveX [10], int8 moveY [11], uint8 flags [12], uint8 pad [13]
 const canvas = document.getElementById('vizCanvas');
 const ctx    = canvas.getContext('2d');
 const TRAIL_LEN = 120;
@@ -707,7 +707,7 @@ let cursorX = canvas.width/2, cursorY = canvas.height/2, trail = [];
 let vizPaused = true;
 let imuSubscribed = false;
 
-// ── Stream diagnostics ────────────────────────────────────────────────────────
+// Stream diagnostics 
 let streamPktCount  = 0;      // packets received this second
 let streamPktTotal  = 0;      // lifetime packet count
 let streamLastPktT  = 0;      // timestamp of last packet (for gap detection)
@@ -722,7 +722,7 @@ function streamDiagReset() {
 function streamDiagPkt() {
   const now = Date.now();
 
-  // Gap detection — warn if >300ms since last packet while streaming
+  // Gap detection - warn if >300ms since last packet while streaming
   if (streamLastPktT) {
     const gap = now - streamLastPktT;
     if (gap > 300) log(`[STREAM] gap ${gap}ms (pkt #${streamPktTotal})`, 'warn');
@@ -731,10 +731,10 @@ function streamDiagPkt() {
   streamPktCount++;
   streamPktTotal++;
 
-  // Reset freeze watchdog — 1.5s without a packet = freeze
+  // Reset freeze watchdog - 1.5s without a packet = freeze
   if (streamFreezeTimer) clearTimeout(streamFreezeTimer);
   streamFreezeTimer = setTimeout(() => {
-    log(`[STREAM] FROZEN — no packet for 1.5s (total rx: ${streamPktTotal})`, 'err');
+    log(`[STREAM] FROZEN - no packet for 1.5s (total rx: ${streamPktTotal})`, 'err');
     streamFreezeTimer = null;
   }, 1500);
 
@@ -750,7 +750,7 @@ function streamDiagPkt() {
 
 // Roll compensation is done entirely in firmware (calibrateGyroBias computes
 // rollSin/rollCos from boot-pose accel and applies the rotation before moveX/moveY).
-// The web visualiser just uses moveX/moveY directly — no re-rotation needed here.
+// The web visualiser just uses moveX/moveY directly - no re-rotation needed here.
 function resetOrient() {}  // kept for call-site compatibility
 
 function vizUpdateIndicator() {
@@ -782,7 +782,7 @@ async function vizSetPaused(paused) {
       await chars.imuStream.stopNotifications();
       imuSubscribed = false;
       streamDiagReset();
-      document.getElementById('orientLabel').textContent = '— not streaming —';
+      document.getElementById('orientLabel').textContent = '- not streaming -';
     } catch(e) { log(`IMU stream stop failed: ${e.message}`,'err'); }
   }
   vizUpdateIndicator();
@@ -792,7 +792,7 @@ function parseImuStream(dv) {
   let view;
   try {
     view = dv instanceof DataView ? new DataView(dv.buffer, dv.byteOffset, dv.byteLength) : new DataView(dv);
-  } catch(e) { log(`parseImuStream: DataView wrap failed — ${e.message}`,'err'); return; }
+  } catch(e) { log(`parseImuStream: DataView wrap failed - ${e.message}`,'err'); return; }
 
   if (view.byteLength < 14) {
     const bytes = new Uint8Array(view.buffer, view.byteOffset, view.byteLength);
@@ -811,7 +811,7 @@ function parseImuStream(dv) {
     moveX  = view.getInt8(10);
     moveY  = view.getInt8(11);
     flags  = view.getUint8(12);
-  } catch(e) { log(`parseImuStream: parse error — ${e.message}`,'err'); return; }
+  } catch(e) { log(`parseImuStream: parse error - ${e.message}`,'err'); return; }
 
   // Feed debug recorder (even when viz is paused)
   feedDebugRow(gyroX, gyroZ, accelX, accelY, accelZ, moveX, moveY, flags);
@@ -826,7 +826,7 @@ function parseImuStream(dv) {
   updateAxisBar('gz', -gyroX, 30000);
 
   if (!idle) {
-    // moveX/moveY are already roll-corrected by firmware — use them directly
+    // moveX/moveY are already roll-corrected by firmware - use them directly
     cursorX = Math.max(4, Math.min(canvas.width  - 4, cursorX + moveX * 1.5));
     cursorY = Math.max(4, Math.min(canvas.height - 4, cursorY + moveY * 1.5));
   }
@@ -894,7 +894,7 @@ function drawInitState() {
   ctx.fillStyle=cssVar('--canvas-idle-text');ctx.font='10px Share Tech Mono,monospace';
   ctx.textAlign='center';ctx.fillText('connect to activate stream',W/2,H/2+4);ctx.textAlign='left';
 }
-// ── 3D Orientation Viewer ─────────────────────────────────────────────────────
+// 3D Orientation Viewer 
 // Device box: L=115mm (X), W=36mm (Y), H=20mm (Z)
 // Complementary filter mirrors firmware: α=0.96, dt from packet rate (~50ms)
 const ORIENT_ALPHA = 0.96;
@@ -932,7 +932,7 @@ function initOrientViewer() {
   orientEdges = new THREE.LineSegments(new THREE.EdgesGeometry(geo), edgeMat);
   orientMesh.add(orientEdges);
 
-  // "Front" face marker — small arrow along +X (length axis)
+  // "Front" face marker - small arrow along +X (length axis)
   const arrowGeo = new THREE.ConeGeometry(0.02, 0.07, 6);
   arrowGeo.rotateZ(-Math.PI / 2);
   arrowGeo.translate(DEVICE_L / 2 + 0.04, 0, 0);
@@ -982,7 +982,7 @@ function orientFeedIMU(ax, ay, az, gyX_mDPS, gyZ_mDPS) {
     qAccel.copy(orientQ);
   }
 
-  // Gyro integration — firmware sends gyroX (pitch) and gyroZ (yaw), mDPS
+  // Gyro integration - firmware sends gyroX (pitch) and gyroZ (yaw), mDPS
   // Map to Three.js axes: gyroZ→world Y, gyroX→world X
   const gyRad = gyX_mDPS * (Math.PI / 180) / 1000;
   const gzRad = gyZ_mDPS * (Math.PI / 180) / 1000;
@@ -1001,7 +1001,7 @@ function orientFeedIMU(ax, ay, az, gyX_mDPS, gyZ_mDPS) {
   orientRenderer.render(orientScene, orientCamera);
 }
 
-// ── Theme ─────────────────────────────────────────────────────────────────────
+// Theme 
 const THEMES = ['auto','dark','light'];
 const THEME_LABELS = {auto:'AUTO',dark:'DARK',light:'LIGHT'};
 let themeIdx = 0;

web/index.html

@@ -39,7 +39,7 @@
 
 <main id="mainContent">
 
-  <!-- ── col-left: cursor motion ──────────────────────────────── -->
+  <!--  col-left: cursor motion  -->
   <div class="col-left">
 
     <div class="section-label">Motion Parameters</div>
@@ -51,7 +51,7 @@
         <div class="param-value" id="valSensitivity">600</div>
       </div>
       <div class="param">
-        <div><div class="param-label">Dead Zone</div><div class="param-desc">Noise floor (rad/s) — raise to reduce drift</div></div>
+        <div><div class="param-label">Dead Zone</div><div class="param-desc">Noise floor (rad/s) - raise to reduce drift</div></div>
         <input type="range" id="slDeadZone" min="0.005" max="0.2" step="0.005" value="0.06"
           oninput="updateDisplay('deadZone',this.value)" onchange="writeConfigBlob()">
         <div class="param-value" id="valDeadZone">0.060</div>
@@ -134,7 +134,7 @@
 
   </div><!-- /col-left -->
 
-  <!-- ── col-mid: button configuration ───────────────────────── -->
+  <!--  col-mid: button configuration  -->
   <div class="col-mid">
 
     <div class="section-label">Tap Configuration</div>
@@ -146,7 +146,7 @@
         </div>
       </div>
       <div class="param">
-        <div><div class="param-label">Tap Freeze Sensitivity</div><div class="param-desc">Jerk² threshold — lower = more aggressive cursor freeze during taps</div></div>
+        <div><div class="param-label">Tap Freeze Sensitivity</div><div class="param-desc">Jerk² threshold - lower = more aggressive cursor freeze during taps</div></div>
         <input type="range" id="slJerkThreshold" min="500" max="10000" step="100" value="2000"
           oninput="updateDisplay('jerkThreshold',this.value)" onchange="writeConfigBlob()">
         <div class="param-value" id="valJerkThreshold">2000</div>
@@ -183,7 +183,7 @@
 
     <div class="section-label">Physical Buttons</div>
     <div class="card">
-      <!-- ── XIAO nRF52840 Sense pin diagram ─────────────────── -->
+      <!--  XIAO nRF52840 Sense pin diagram  -->
       <div class="xiao-wrap">
         <svg id="xiaoSvg" viewBox="0 0 200 278" xmlns="http://www.w3.org/2000/svg" style="display:block;width:100%;max-width:200px">
           <!-- USB-C connector -->
@@ -301,7 +301,7 @@
     <div class="cmd-grid">
       <button class="cmd-btn calibrate" id="btnCal" onclick="sendCalibrate()" disabled>
         <span class="cmd-icon">⊕</span><span>Calibrate Gyro</span>
-        <span class="cmd-desc">Hold device still — recalculates bias + records cal temperature.</span>
+        <span class="cmd-desc">Hold device still - recalculates bias + records cal temperature.</span>
       </button>
       <button class="cmd-btn reset" id="btnReset" onclick="confirmReset()" disabled>
         <span class="cmd-icon">⚠</span><span>Factory Reset</span>
@@ -314,7 +314,7 @@
 
   </div><!-- /col-mid -->
 
-  <!-- ── col-right: live monitoring ───────────────────────────── -->
+  <!--  col-right: live monitoring  -->
   <div class="col-right">
 
     <div class="section-label">Live Cursor Visualiser</div>
@@ -350,7 +350,7 @@
     <div class="section-label">Device Orientation</div>
     <div class="card orient-card">
       <canvas id="orientCanvas"></canvas>
-      <div style="font-size:9px;color:var(--label);text-align:center;margin-top:6px" id="orientLabel">— not streaming —</div>
+      <div style="font-size:9px;color:var(--label);text-align:center;margin-top:6px" id="orientLabel">- not streaming -</div>
     </div>
 
     <div class="section-label">Live Telemetry</div>

web/style.css

@@ -34,7 +34,7 @@
     --tap-right:        rgba(255,61,113,0.35);
   }
 
-  /* ── Light theme (explicit) ──────────────────────────────────────────────── */
+  /*  Light theme (explicit)  */
   :root.theme-light {
     --bg:      #f0f2f5;
     --panel:   #ffffff;
@@ -66,7 +66,7 @@
   }
 
 
-  /* ── Auto light (OS hint; explicit class overrides) ──────────────────────── */
+  /*  Auto light (OS hint; explicit class overrides)  */
   @media (prefers-color-scheme: light) {
     :root:not(.theme-dark) {
       --bg:      #f0f2f5;
@@ -153,7 +153,7 @@
   .col-mid   { display:grid; gap:12px; }
   .col-right { display:grid; gap:12px; position:sticky; top:80px; }
 
-  /* ── XIAO pin diagram ─────────────────────────────────────── */
+  /*  XIAO pin diagram  */
   .xiao-wrap { display:flex; flex-direction:column; align-items:center; padding:8px 0 14px; }
   .pin-legend { display:flex; gap:20px; justify-content:center; font-family:var(--mono); font-size:9px; margin-top:10px; letter-spacing:0.08em; }
   .pleg.left   { color:var(--ok); }
@@ -161,7 +161,7 @@
   .pleg.mid    { color:var(--accent); }
   .xiao-divider { border:none; border-top:1px solid var(--border); margin:0 -20px 12px; }
 
-  /* ── Responsive ───────────────────────────────────────────── */
+  /*  Responsive  */
   @media (max-width:1100px) {
     main { grid-template-columns:1fr 380px; grid-template-rows:auto auto; }
     .col-left  { grid-column:1; grid-row:1; }
@@ -288,7 +288,7 @@
   .btn-confirm { border-color:var(--accent2); color:var(--accent2); }
   .btn-confirm:hover { background:var(--accent2); color:var(--bg); }
 
-  /* ── Debug modal ────────────────────────────────────────────────────────── */
+  /*  Debug modal  */
   .debug-modal { max-width:720px; padding:20px; border-color:var(--accent); }
   .debug-modal h3 { color:var(--accent); margin-bottom:0; }
   .debug-header { display:flex; justify-content:space-between; align-items:center; margin-bottom:14px; }