diff --git a/render.py b/render.py
index 48799fc..cb2483b 100644
--- a/render.py
+++ b/render.py
@@ -3,13 +3,13 @@ import pynmea2
 import serial
 import io
 
-ser = serial.Serial('/dev/ttyS1', 9600, timeout=5.0)
+ser = serial.Serial('/dev/ttyACM0', 9600, timeout=5.0)
 sio = io.TextIOWrapper(io.BufferedRWPair(ser, ser))
 last_time=00
 
 
 def check_last_update(time,last_time):
-    if nmea==last_nmea:
+    if time==last_time:
         return False
     else:
         return True
@@ -27,10 +27,12 @@ while 1:
     else:
         if check_last_update(time=msg.timestamp,last_time=last_time)==True:
             if last_time==00:
-                m = Map(center=msg.latitude, msg.longitude, zoom=15)
+                center = (msg.latitude, msg.longitude,)
+                m = Map(center=center, zoom=15)
                 marker = Marker(location=center, draggable=False)
                 m.add_layer(marker);
                 display(m)
+                last_time=msg.timestamp
             else:
                 marker.location=(msg.latitude, msg.longitude)
                 last_time=msg.timestamp