diff --git a/microcontroller/ctrl.py b/microcontroller/ctrl.py
index b65d116..64c0de7 100644
--- a/microcontroller/ctrl.py
+++ b/microcontroller/ctrl.py
@@ -1,5 +1,6 @@
 import serial
 import time
+import colorsys
 
 channels = [
     192,  # pan
@@ -18,18 +19,35 @@ start_addr = 10
 with serial.Serial("/dev/ttyUSB0", 115200) as ser:
 
     payload = bytearray(512)
-    # payload.extend(channels)
-    payload[(start_addr - 1) : (start_addr - 1 + len(channels))] = channels
 
-    print(payload)
+    FPS = 20
+    FRAME_TIME = 1 / FPS
+    t = 0
 
     while True:
+        
+        loop_start = time.time()
 
+        r, g, b = colorsys.hls_to_rgb(t, 0.5, 1)
+
+        channels[3] = int(255 * r)
+        channels[4] = int(255 * g)
+        channels[5] = int(255 * b)
+
+        payload[(start_addr - 1) : (start_addr - 1 + len(channels))] = channels
+        
         ser.write(payload)
         ser.flush()
 
-        time.sleep(1/50)
+        t += FRAME_TIME
+        t %= 1
+        
+        loop_time = time.time() - loop_start
+        if loop_time < FRAME_TIME:
+            time.sleep(FRAME_TIME - loop_time)
+        else:
+            print("loop took too long!")
+            
+        print(f"loop time: {1000 * loop_time:0.2f}ms busy, {1000 * (time.time() - loop_start):0.2f}ms total")
 
-        print(".")
-
-    #print(ser.read_all())
+    # print(ser.read_all())