diff --git a/timeturner.py b/timeturner.py
index 666c7f9..e363463 100644
--- a/timeturner.py
+++ b/timeturner.py
@@ -8,23 +8,30 @@ from datetime import datetime
 # Serial config
 SERIAL_PORT = "/dev/ttyACM0"
 BAUD_RATE = 115200
-REFRESH_INTERVAL = 0.5  # seconds
+UI_REFRESH_INTERVAL = 0.25  # seconds
+SIGNAL_TIMEOUT = 1.5  # seconds
 
 # Regex pattern
 ltc_pattern = re.compile(
     r"\[(LOCK|FREE)\]\s+(\d{2}:\d{2}:\d{2}[:;]\d{2})\s+\|\s+([\d.]+fps)", re.IGNORECASE
 )
 
-# Stats
-lock_count = 0
-free_count = 0
-last_frame = None
-drift_warnings = []
+# Shared state
+state = {
+    "ltc_status": "--",
+    "ltc_timecode": "--:--:--:--",
+    "framerate": "--",
+    "system_clock": "--:--:--.---",
+    "offset_str": "--",
+    "lock_count": 0,
+    "free_count": 0,
+    "last_received": None,
+    "signal_loss": False
+}
 
 def parse_timecode(tc_str):
-    sep = ":" if ":" in tc_str else ";"
     h, m, s, f = map(int, tc_str.replace(";", ":").split(":"))
-    return h, m, s, f, sep
+    return h, m, s, f
 
 def timecode_to_milliseconds(h, m, s, f, fps):
     return int(((h * 3600 + m * 60 + s) * 1000) + (f * (1000 / fps)))
@@ -39,79 +46,78 @@ def format_offset(ms, fps):
     frame_offset = int(round(ms / frame_duration))
     return f"{ms:+} ms ({frame_offset:+} frames)"
 
+def serial_reader(ser):
+    global state
+    while ser.in_waiting:
+        line = ser.readline().decode(errors='ignore').strip()
+        match = ltc_pattern.match(line)
+        now = datetime.now()
+
+        if match:
+            status, tc_str, fps_str = match.groups()
+            fps = float(fps_str.lower().replace("fps", ""))
+            h, m, s, f = parse_timecode(tc_str)
+
+            # Update shared state
+            state["ltc_status"] = status
+            state["ltc_timecode"] = tc_str
+            state["framerate"] = fps_str
+            state["system_clock"] = now.strftime("%H:%M:%S.%f")[:-3]
+            state["offset_str"] = format_offset(get_offset(now, h, m, s, f, fps), fps)
+            state["last_received"] = time.time()
+            state["signal_loss"] = False
+            if status == "LOCK":
+                state["lock_count"] += 1
+            else:
+                state["free_count"] += 1
+
 def draw_ui(stdscr):
-    global lock_count, free_count, last_frame, drift_warnings
+    global state
 
     curses.curs_set(0)
     stdscr.nodelay(True)
 
     try:
-        ser = serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=1)
+        ser = serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=0.1)
     except serial.SerialException as e:
         stdscr.addstr(0, 0, f"[ERROR] Couldn't open {SERIAL_PORT}: {e}")
         stdscr.getch()
         return
 
-    # Init variables
-    ltc_status = "--"
-    ltc_timecode = "--:--:--:--"
-    framerate = "--"
-    offset_str = "--"
-
     while True:
         try:
-            line = ser.readline().decode(errors='ignore').strip()
-            match = ltc_pattern.match(line)
-            now = datetime.now()
+            # Read as fast as possible
+            serial_reader(ser)
 
-            if match:
-                status, tc_str, fps_str = match.groups()
-                ltc_status = status
-                ltc_timecode = tc_str
-                framerate = fps_str
-                fps = float(fps_str.lower().replace("fps", ""))
+            # Check for signal timeout
+            if state["last_received"]:
+                elapsed = time.time() - state["last_received"]
+                if elapsed > SIGNAL_TIMEOUT:
+                    state["signal_loss"] = True
 
-                h, m, s, f, sep = parse_timecode(tc_str)
-                current_frame = timecode_to_milliseconds(h, m, s, f, fps)
-
-                # Drift detection
-                if last_frame is not None:
-                    expected = last_frame + int(1000 / fps)
-                    if abs(current_frame - expected) > int(2 * (1000 / fps)):
-                        drift_warnings.append(f"Drift: Δ{current_frame - last_frame} ms")
-                        if len(drift_warnings) > 3:
-                            drift_warnings.pop(0)
-                last_frame = current_frame
-
-                # Sync offset
-                offset_ms = get_offset(now, h, m, s, f, fps)
-                offset_str = format_offset(offset_ms, fps)
-
-                # Stats
-                if ltc_status == "LOCK":
-                    lock_count += 1
-                else:
-                    free_count += 1
-
-            # UI
+            # Draw UI
             stdscr.clear()
-            stdscr.addstr(0, 0, "🕰  NTP Timeturner v0.3")
-            stdscr.addstr(2, 0, f"LTC Status   : {ltc_status}")
-            stdscr.addstr(3, 0, f"LTC Timecode : {ltc_timecode}")
-            stdscr.addstr(4, 0, f"Frame Rate   : {framerate}")
-            stdscr.addstr(5, 0, f"System Clock : {now.strftime('%H:%M:%S.%f')[:-3]}")
-            stdscr.addstr(6, 0, f"Sync Offset  : {offset_str}")
-            stdscr.addstr(7, 0, f"Lock Ratio   : {lock_count} LOCK / {free_count} FREE")
-            if drift_warnings:
-                stdscr.addstr(9, 0, f"⚠️  {drift_warnings[-1]}")
-            stdscr.addstr(11, 0, "Press Ctrl+C to exit.")
+            stdscr.addstr(0, 0, "🕰  NTP Timeturner v0.4")
+
+            if state["signal_loss"]:
+                stdscr.addstr(2, 0, "⚠️  No LTC signal detected!")
+                stdscr.addstr(3, 0, f"Last seen: {elapsed:.2f}s ago")
+            else:
+                stdscr.addstr(2, 0, f"LTC Status   : {state['ltc_status']}")
+                stdscr.addstr(3, 0, f"LTC Timecode : {state['ltc_timecode']}")
+                stdscr.addstr(4, 0, f"Frame Rate   : {state['framerate']}")
+                stdscr.addstr(5, 0, f"System Clock : {state['system_clock']}")
+                stdscr.addstr(6, 0, f"Sync Offset  : {state['offset_str']}")
+                stdscr.addstr(7, 0, f"Lock Ratio   : {state['lock_count']} LOCK / {state['free_count']} FREE")
+
+            stdscr.addstr(9, 0, "Press Ctrl+C to exit.")
             stdscr.refresh()
-            time.sleep(REFRESH_INTERVAL)
+            time.sleep(UI_REFRESH_INTERVAL)
 
         except KeyboardInterrupt:
             break
         except Exception as e:
-            stdscr.addstr(13, 0, f"[EXCEPTION] {e}")
+            stdscr.addstr(11, 0, f"[EXCEPTION] {e}")
             stdscr.refresh()
             time.sleep(1)