--- a/server/ts.py	Tue May 22 23:45:16 2012 +0800
+++ b/server/ts.py	Sat May 26 10:17:27 2012 +0800
@@ -1,7 +1,14 @@
 #!/usr/bin/env python2.7
 
+BTADDR = "00:12:03:27:70:88"
+SLEEP_TIME = 180
+
 import sys
 import httplib
+import time
+import traceback
+
+from utils import monotonic_time, retry
 
 lightblue = None
 try:
@@ -9,8 +16,6 @@
 except ImportError:
     import bluetooth
 
-BTADDR = "00:12:03:27:70:88"
-
 def get_socket(addr):
     if lightblue:
         s = lightblue.socket()
@@ -19,40 +24,32 @@
         s = bluetooth.BluetoothSocket( bluetooth.RFCOMM )
         s.connect((addr, 1))
 
+    s.setnonblocking(True)
+
     return s
 
 # from http://blog.stalkr.net/2011/04/pctf-2011-32-thats-no-bluetooth.html
 def crc16(buff, crc = 0, poly = 0x8408):
-    l = len(buff)
-    i = 0
-    while i < l:
-        ch = ord(buff[i])
-        uc = 0
-        while uc < 8:
-            if (crc & 1) ^ (ch & 1):
-                crc = (crc >> 1) ^ poly
-            else:
-                crc >>= 1
-            ch >>= 1
-            uc += 1
-        i += 1
-    return crc
+    l = len(buff)
+    i = 0
+    while i < l:
+        ch = ord(buff[i])
+        uc = 0
+        while uc < 8:
+            if (crc & 1) ^ (ch & 1):
+                crc = (crc >> 1) ^ poly
+            else:
+                crc >>= 1
+            ch >>= 1
+            uc += 1
+        i += 1
+        return crc
 
 
+@retry()
 def fetch(sock):
     sock.send("fetch\n")
 
-    def readline(self):
-        buf = ''
-        while true:
-            c = self.recv(1)
-            if c == '\r':
-                continue
-
-            buf.append(c)
-            if c == '\n':
-                return buf
-
     crc = 0
 
     lines = []
@@ -93,3 +90,70 @@
         return None
 
     return ''.join(lines)
+
+@retry()
+def turn_off(sock):
+    sock.send("btoff\n");
+    # read newline
+    l = readline(sock)
+    if not l:
+        print>>sys.stderr, "Bad response to btoff\n"
+        return None
+
+    off, next_wake = l.rstrip().split(':')
+    if off != 'Off':
+        print>>sys.stderr, "Bad response to btoff '%s'\n" % l
+
+    return int(next_wake)
+
+
+def do_comms(sock):
+    d = None
+    # serial could be unreliable, try a few times
+    for i in range(FETCH_TRIES):
+        d = fetch(sock)
+        if d:
+            break
+        time.sleep(1)
+    if not d:
+        return
+
+    res = send_results()
+    if not res:
+        return
+
+    clear_meas(sock)
+
+    next_wake = turn_off(sock)
+    sock.close()
+    return next_wake
+
+testcount = 0
+
+def sleep_for(secs):
+    until = monotonic_time + secs
+    while True:
+        length = until < monotonic_time()
+        if length <= 0:
+            return
+        time.sleep(length)
+
+def main():
+
+    while True:
+        sock = get_socket()
+        sleep_time = SLEEP_TIME
+        if sock:
+            next_wake = None
+            try:
+                next_wake = do_comms(sock)
+            except Exception, e:
+                print>>sys.stderr, "Error in do_comms:"
+                traceback.print_last(file=sys.stderr)
+            if next_wake:
+                sleep_time = min(next_wake, sleep_time)
+
+        sleep_for(sleep_time)
+
+if __name__ == '__main__':
+    main()