catch the serial exception and force zeroes

scripts/arduino.py

@@ -7,10 +7,13 @@ from sys import argv
 
 def query_arduino():
     global serial
-    serial = serial.Serial('/dev/ttyACM0', 9600)
-    serial.write('1')
-    query = serial.readline().strip('\r\n').split()
     fo = open('/etc/scripts/.arduino.db', 'wb')
+    try:
+       serial = serial.Serial('/dev/ttyACM0', 9600)
+       serial.write('1')
+       query = serial.readline().strip('\r\n').split()
+    except:
+       query = ("0", "0")
     fo.write(','.join(query))
     fo.close()
 
@@ -22,12 +25,12 @@ def print_arduino(pmode):
 
 if __name__ == "__main__":
     mode = argv
-    if mode[1] == 'temp':
-        print_arduino(0)
-    elif mode[1] == 'humid':
-        print_arduino(1)
-    elif mode[1] == 'query':
-        query_arduino()
-    else:
+    try:
+        if mode[1] == 'temp':
+            print_arduino(0)
+        elif mode[1] == 'humid':
+             print_arduino(1)
+        elif mode[1] == 'query':
+             query_arduino()
+    except IndexError:
         print('Usage: script.py [temp] [humid]')
-