diff --git a/micropizza/main.py b/micropizza/main.py
index edf01b0..cc568cb 100644
--- a/micropizza/main.py
+++ b/micropizza/main.py
@@ -2,6 +2,8 @@ from machine import PWM, UART, Pin, Timer
 from micropython import const
 import time
 
+_DEBUG = const(1)
+
 _PWM_MAX = const(65535)
 _PWM_FREQ = const(2000)
 
@@ -39,8 +41,7 @@ CMD_UI = 'U'        # user interaction
 CMD_RC = 'C'        # recording
 CMD_RW = 'R'        # rewind
 
-LED = PWM(Pin(25))
-LED.freq(_PWM_FREQ)
+LED = Pin(25, Pin.OUT)
 
 class Scroll:
     def __init__(self, cnt_pin:Pin, end_pin:Pin, en_pin:PWM, a_pin:Pin, b_pin:Pin) -> None:
@@ -128,15 +129,18 @@ def motor_hor(*opts):
 def _motorctrl(scroll: Scroll, steps: int, *opts):
     end = scroll.c + steps
     print(f'motorctrl, end={end}, scroll.c={scroll.c}')
-    #while True:
-    #    err = end - scroll.c
-    #    if abs(err) > 4:
-    #        speed = (err / (2 * steps)) + 0.5
-    #        scroll.speed = int(100 * speed)
-    #    else:
-    #        scroll.speed = 0
-    #        break
-    #    time.sleep_ms(5)   
+    try:
+        while True:
+            err = end - scroll.c
+            if abs(err) > 4:
+                speed = (err / (2 * steps)) + 0.5
+                scroll.speed = int(100 * speed)
+            else:
+                scroll.speed = 0
+                break
+            time.sleep_ms(5)
+    finally:
+        scroll.speed = 0
 
 def backlight(*opts):
     _fade_led(pwm_bl, *opts)
@@ -226,9 +230,20 @@ def parseCmd(cmd_str: str):
     parms = []
     if len(parm_str) != 0:
         parms = [int(x) for x in parm_str.split('+')]
+    if _DEBUG:
+        print(f'parsed command: {cmd}:{parms}')
     resp = choice_map[cmd](*parms)
     uart0.write(f'{resp}\n'.encode('utf-8'))
 
+def flash_led(times: int = 1, on_ms: int = 200, off_ms: int = 500):
+    LED.off()
+    times = 1 if times < 1 else times
+    for i in range(times):
+        LED.on()
+        time.sleep_ms(on_ms)
+        LED.off()
+        time.sleep_ms(off_ms)
+
 
 if __name__ == '__main__':
     pin_bl_a.value(1)
@@ -236,6 +251,7 @@ if __name__ == '__main__':
     pin_fl_a.value(1)
     pin_fl_b.value(0)
     rxData = ''
+    flash_led(2)
     while True:
         rxBuf = uart0.read(1)
         if rxBuf is not None: