Add timestamps

Add newlines after each sample, insert a timestamp once per minute,
and don't forget to flush().

Also fix syntax errors from missing colons and function arguments.

main.py

@@ -1,5 +1,6 @@
 #!/usr/bin/python
 import os
+import time
 import serial
 
 def filename(i):
@@ -24,14 +25,14 @@ def open_file():
 
   return open(logdir + '/' + filename(i), 'w')
 
-def parse_packet(packet)
+def parse_packet(packet):
   length = len(packet)
   result = 0
   for i in range(length):
     result |= (packet[length - 1 - i] & 0x7F) << 7*i
   return result
 
-def read_packet(port)
+def read_packet(port):
   while True:
     data = ord(port.read(1))
     if (data & 0x80) != 0:
@@ -42,8 +43,17 @@ def main():
   outfile = open_file()
   port = open_serial()
 
+  lasttime = time.time()
   while True:
-    outfile.write(read_packet())
+    outfile.write(str(read_packet(port)))
+    outfile.write('\n')
+    if time.time() - lasttime  > 60:
+      lasttime = time.time()
+      stamp = 'time ' + str(int(time.time()))
+      outfile.write(stamp)
+      outfile.write('\n')
+      print stamp
+    outfile.flush()
 
   outfile.close()
   port.close()