diff --git a/firmware/main.py b/firmware/main.py
index 6e7d0fb..30c7067 100644
--- a/firmware/main.py
+++ b/firmware/main.py
@@ -1,21 +1,41 @@
+"""LightSync firmware — main entry point.
+
+Two asyncio tasks:
+  1. udp_listener_task: non-blocking UDP socket, parses packets, updates state
+  2. render_task: 60fps loop, renders animations or writes frame data to strip
+
+Modes:
+  - 'idle': strip is off, waiting for first packet
+  - 'animation': running a locally-rendered animation (from 0xAC command)
+  - 'frame': displaying raw pixel data (from DRGB/DRGBW/DNRGB packets)
+
+Frame timeout: if no frame packet arrives for 2 seconds, reverts to last animation.
+"""
 import asyncio
 import socket
 import select
 import time
 import json
 
-from protocol import classify_packet, parse_animation_cmd
+from protocol import (
+    classify_packet, parse_animation_cmd,
+    parse_drgb, parse_drgbw, parse_dnrgb, FrameAssembler
+)
 from led_driver import create_strip
 from animations import create_animation
 
 # --- Global state ---
 config = None
 strip = None
-current_mode = 'idle'          # 'idle', 'animation', 'frame'
-current_animation = None       # dict from parse_animation_cmd
-current_anim_instance = None   # animation object with render()
+current_mode = 'idle'           # 'idle', 'animation', 'frame'
+current_animation = None        # dict from parse_animation_cmd
+current_anim_instance = None    # animation object with render()
 animation_start_ms = 0
-frame_pixels = None            # set by frame packets
+frame_pixels = None             # list of (R,G,B) or (R,G,B,W) tuples
+frame_is_rgbw = False           # True if last frame was DRGBW
+last_frame_ms = 0               # ticks_ms of last frame packet
+frame_assembler = None          # FrameAssembler for DNRGB
+FRAME_TIMEOUT_MS = 2000         # revert to animation after 2s without frames
 
 
 def load_config():
@@ -30,7 +50,8 @@ def load_config():
 async def udp_listener_task(port):
     """Non-blocking UDP listener using select.poll(0) inside asyncio."""
     global current_mode, current_animation, current_anim_instance
-    global animation_start_ms, frame_pixels
+    global animation_start_ms, frame_pixels, frame_is_rgbw
+    global last_frame_ms, frame_assembler
 
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     sock.bind(('0.0.0.0', port))
@@ -56,10 +77,29 @@ async def udp_listener_task(port):
                         animation_start_ms = time.ticks_ms()
                         print('[udp] Animation:', cmd['animation'])
 
-                elif ptype in ('drgb', 'drgbw', 'dnrgb'):
-                    # Frame handling added by Plan 07-03
+                elif ptype == 'drgb':
+                    pixels = parse_drgb(data)
+                    frame_pixels = pixels
+                    frame_is_rgbw = False
                     current_mode = 'frame'
-                    print('[udp] Frame packet:', ptype, len(data), 'bytes')
+                    last_frame_ms = time.ticks_ms()
+
+                elif ptype == 'drgbw':
+                    pixels = parse_drgbw(data)
+                    frame_pixels = pixels
+                    frame_is_rgbw = True
+                    current_mode = 'frame'
+                    last_frame_ms = time.ticks_ms()
+
+                elif ptype == 'dnrgb':
+                    start_idx, pixels = parse_dnrgb(data)
+                    now = time.ticks_ms()
+                    complete = frame_assembler.feed(start_idx, pixels, now)
+                    if complete:
+                        frame_pixels = complete
+                        frame_is_rgbw = False  # DNRGB is always RGB
+                        current_mode = 'frame'
+                        last_frame_ms = now
 
                 else:
                     print('[udp] Unknown packet type:', data[0] if data else '?')
@@ -70,30 +110,46 @@ async def udp_listener_task(port):
 
 
 async def render_task():
-    """Animation render loop at ~60fps."""
+    """Animation/frame render loop at ~60fps."""
     global current_mode, frame_pixels
 
     while True:
-        if current_mode == 'animation' and current_anim_instance:
+        if current_mode == 'frame' and frame_pixels:
+            # Check frame timeout — revert to animation if no packets for 2s
+            if time.ticks_diff(time.ticks_ms(), last_frame_ms) > FRAME_TIMEOUT_MS:
+                if current_anim_instance:
+                    current_mode = 'animation'
+                    animation_start_ms = time.ticks_ms()
+                    print('[render] Frame timeout, reverting to animation')
+                else:
+                    current_mode = 'idle'
+                    strip.clear()
+            else:
+                # Write frame to strip
+                if frame_is_rgbw:
+                    strip.write_rgbw(frame_pixels)
+                else:
+                    strip.write_rgb(frame_pixels)
+
+        elif current_mode == 'animation' and current_anim_instance:
             t = time.ticks_diff(time.ticks_ms(), animation_start_ms) / 1000.0
             pixels = current_anim_instance.render(t, config['led_count'])
             strip.write_rgb(pixels)
-        elif current_mode == 'frame' and frame_pixels:
-            # Plan 07-03 adds frame write logic here
-            pass
 
         await asyncio.sleep_ms(16)  # ~60 fps
 
 
 async def main():
-    global config, strip
+    global config, strip, frame_assembler
 
     config = load_config()
     strip = create_strip(config)
     strip.clear()
+    frame_assembler = FrameAssembler(config['led_count'])
 
     print('[main] LightSync firmware ready')
     print('[main] Strip:', config['strip_type'], '/', config['led_count'], 'LEDs')
+    print('[main] UDP port:', config['udp_port'])
 
     asyncio.create_task(udp_listener_task(config['udp_port']))
     asyncio.create_task(render_task())
@@ -101,5 +157,4 @@ async def main():
     while True:
         await asyncio.sleep(1)
 
-
 asyncio.run(main())