diff --git a/web/app.js b/web/app.js
index e6d056e..f9cb1c6 100644
--- a/web/app.js
+++ b/web/app.js
@@ -37,7 +37,10 @@ let _gattDepth = 0;
 
 function _withTimeout(promise, ms) {
   return new Promise((resolve, reject) => {
-    const t = setTimeout(() => reject(new Error(`GATT timeout (${ms}ms)`)), ms);
+    const t = setTimeout(() => {
+      console.warn(`[GATT] operation timed out after ${ms}ms`);
+      reject(new Error(`GATT timeout (${ms}ms)`));
+    }, ms);
     promise.then(v => { clearTimeout(t); resolve(v); },
                  e => { clearTimeout(t); reject(e); });
   });
@@ -45,6 +48,7 @@ function _withTimeout(promise, ms) {
 
 function _enqueue(fn) {
   if (_gattDepth >= GATT_MAX_DEPTH) {
+    console.warn(`[GATT] write dropped - queue depth ${_gattDepth} >= max ${GATT_MAX_DEPTH}`);
     return Promise.reject(new Error('GATT queue full - device unreachable?'));
   }
   _gattDepth++;
@@ -57,6 +61,7 @@ function gattWrite(char, value) { return _enqueue(() => char.writeValueWithRespo
 function gattCmd (char, value)  { return _enqueue(() => char.writeValueWithoutResponse(value)); }
 
 function gattQueueReset() {
+  console.log('[GATT] queue reset');
   // Drain the chain so a reconnect starts with a fresh resolved promise
   _gattQueue = Promise.resolve();
   _gattDepth = 0;
@@ -133,7 +138,9 @@ async function discoverServices() {
 
     // Telemetry notify (1 Hz) - also carries chargeStatus
     chars.telemetry.addEventListener('characteristicvaluechanged', e => parseTelemetry(e.target.value));
+    console.log('[TELEM] subscribing to notifications');
     await chars.telemetry.startNotifications();
+    console.log('[TELEM] subscribed, reading initial value');
     // 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
@@ -487,6 +494,7 @@ function parseTelemetry(dv) {
   // chargeStatus is now delivered via telemetry (no separate characteristic)
   if (chargeStatus !== currentChargeStatus) {
     currentChargeStatus = chargeStatus;
+    console.log('[TELEM] charge status:', ['discharging','charging','full'][chargeStatus] ?? chargeStatus);
     updateChargeUI();
   }
 
@@ -547,6 +555,7 @@ let debugLiveRing = [];
 let debugT0 = 0;
 
 function openDebugModal() {
+  console.log('[DEBUG] modal opened (imuSubscribed=' + imuSubscribed + ')');
   debugModalOpen = true;
   debugT0 = Date.now();
   debugLiveRing = [];
@@ -555,6 +564,7 @@ function openDebugModal() {
   if (!imuSubscribed && chars.imuStream) vizSetPaused(false);
 }
 function closeDebugModal() {
+  console.log('[DEBUG] modal closed');
   debugModalOpen = false;
   document.getElementById('debugOverlay').classList.remove('show');
 }
@@ -706,6 +716,7 @@ const TRAIL_LEN = 120;
 let cursorX = canvas.width/2, cursorY = canvas.height/2, trail = [];
 let vizPaused = true;
 let imuSubscribed = false;
+let _prevIdle = false;
 
 // Stream diagnostics 
 let streamPktCount  = 0;      // packets received this second
@@ -715,7 +726,9 @@ let streamLastRateT = 0;      // timestamp of last rate log
 let streamFreezeTimer = null; // fires if no packet for >1s while subscribed
 
 function streamDiagReset() {
+  console.log('[STREAM] diagnostics reset');
   streamPktCount = streamPktTotal = streamLastPktT = streamLastRateT = 0;
+  _prevIdle = false;
   if (streamFreezeTimer) { clearTimeout(streamFreezeTimer); streamFreezeTimer = null; }
 }
 
@@ -771,6 +784,7 @@ function vizUpdateIndicator() {
 async function vizSetPaused(paused) {
   vizPaused = paused;
   if (!paused && chars.imuStream && !imuSubscribed) {
+    console.log('[STREAM] requesting subscribe');
     try {
       await chars.imuStream.startNotifications();
       imuSubscribed = true;
@@ -778,12 +792,15 @@ async function vizSetPaused(paused) {
       log('IMU stream subscribed','ok');
     } catch(e) { log(`IMU stream start failed: ${e.message}`,'err'); vizPaused = true; }
   } else if (paused && imuSubscribed) {
+    console.log(`[STREAM] requesting unsubscribe (total rx: ${streamPktTotal})`);
     try {
       await chars.imuStream.stopNotifications();
       imuSubscribed = false;
       streamDiagReset();
       document.getElementById('orientLabel').textContent = '- not streaming -';
     } catch(e) { log(`IMU stream stop failed: ${e.message}`,'err'); }
+  } else {
+    console.log(`[STREAM] vizSetPaused(${paused}) - no action (imuSubscribed=${imuSubscribed})`);
   }
   vizUpdateIndicator();
 }
@@ -817,6 +834,7 @@ function parseImuStream(dv) {
   feedDebugRow(gyroX, gyroZ, accelX, accelY, accelZ, moveX, moveY, flags);
 
   if (vizPaused) return;
+
   const idle   = !!(flags & 0x01);
   const single = !!(flags & 0x02);
   const dbl    = !!(flags & 0x04);
@@ -835,6 +853,13 @@ function parseImuStream(dv) {
 
   streamDiagPkt();
 
+  if (idle !== _prevIdle) {
+    console.log(`[STREAM] idle → ${idle ? 'idle' : 'active'} (pkt #${streamPktTotal})`);
+    _prevIdle = idle;
+  }
+  if (single) console.log(`[STREAM] single tap (pkt #${streamPktTotal})`);
+  if (dbl)    console.log(`[STREAM] double tap (pkt #${streamPktTotal})`);
+
   if (single) flashTap('Left');
   if (dbl)    flashTap('Right');
   drawViz(idle);