Add gitignore

Add automatic ESU finding code
Add exception handlers in the main loop to make the system transparently restart if something dies

.gitignore

@@ -0,0 +1,2 @@
+*~
+*.pyc

esu-bridge.py

@@ -4,41 +4,74 @@
 import mrbus
 import sys
 import time
+import socket
 import MRBusThrottle
-
+import netUtils
 
 statusInterval = 2
 baseAddress = 0xD4
 
-mrbee = mrbus.mrbus("/dev/ttyUSB2", baseAddress, logall=True, logfile=sys.stdout, busType='mrbee')
-cmdStn = esu.ESUConnection()
-cmdStn.connect('192.168.7.191')
+# Big loop - runs as long as the program is alive
+while 1:
+
+   # Initialization loop - runs until both ESU and MRBus are connected
+   while 1:
+      try:
+         throttles = { }
+         print "Looking for ESU CabControl command station"
+         esuIP = ""
+         esuIP = netUtils.esuFind()
+         if esuIP is None:
+            print "No command station found, waiting and retrying..."
+            sleep(1)
+            continue
+
+         cmdStn = esu.ESUConnection()
+         cmdStn.connect(esuIP)
+
+         mrbee = mrbus.mrbus("/dev/ttyUSB2", baseAddress, logall=True, logfile=sys.stdout, busType='mrbee')
+         break
 
-throttles = { }
+      except(KeyboardInterrupt):
+         cmdStn.disconnect()
+         mrbee.disconnect()
+         sys.exit()
+      except:
+         cmdStn.disconnect()
+         mrbee.disconnect()
+         continue
 
-lastStatusTime = time.time()
 
+   lastStatusTime = time.time()
 
-while 1:
-   pkt = mrbee.getpkt()
+   # Main Run Loop - runs until something weird happens
+   while 1:
+      try:
+         pkt = mrbee.getpkt()
 
-   if time.time() > lastStatusTime + statusInterval:
-      mrbee.sendpkt(0xFF, [ord('A')])
-      lastStatusTime = time.time()
+         if time.time() > lastStatusTime + statusInterval:
+            mrbee.sendpkt(0xFF, [ord('A')])
+            lastStatusTime = time.time()
 
-   if pkt is None:
-      continue
+         if pkt is None:
+            continue
 
-   # Bypass anything that doesn't look like a throttle packet
-   if pkt.cmd != 0x53 or len(pkt.data) != 10 or baseAddress != pkt.dest:
-      continue
+         # Bypass anything that doesn't look like a throttle packet
+         if pkt.cmd != 0x53 or len(pkt.data) != 10 or baseAddress != pkt.dest:
+            continue
 
-   if pkt.src not in throttles:
-      throttles[pkt.src] = MRBusThrottle.MRBusThrottle()
+         if pkt.src not in throttles:
+            throttles[pkt.src] = MRBusThrottle.MRBusThrottle()
 
-   throttles[pkt.src].update(cmdStn, pkt)
-
-
+         throttles[pkt.src].update(cmdStn, pkt)
 
-cmdStn.disconnect()
+      except (KeyboardInterrupt):
+         cmdStn.disconnect()
+         mrbee.disconnect()
+         sys.exit()
+      except:
+         print "Caught some sort of exception, restarting the whole thing"
+         cmdStn.disconnect()
+         mrbee.disconnect()
+         break
 

mrbus.py

@@ -94,6 +94,8 @@ def __init__(self, port, addr, logfile=None, logall=False, extra=False):
     self.addr=addr
 #    self.buf=deque()
 
+  def disconnect(self):
+     self.serial.close()
 
   def log(self, error, msg):
     if not self.logfile:
@@ -193,6 +195,9 @@ def log(self, error, msg):
       s="  log:"
     self.logfile.write(s+repr(msg)+'\n')
 
+  def disconnect(self):
+     self.serial.close()
+
   def getpkt(self):
 
     while 1:
@@ -353,6 +358,9 @@ def mrbusCRC16Update(crc, a):
    return (crc16_h<<8) | crc16_l
 
 class mrbus(object):
+  def disconnect(self):
+     self.mrbs.disconnect()
+
   def __init__(self, port, addr=None, logfile=None, logall=False, extra=False, busType='mrbus'):
     if type(port)==str:
       port = serial.Serial(port, 115200, rtscts=True)

netUtils.py

@@ -0,0 +1,36 @@
+from time import time
+import socket
+
+def get_ip():
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    try:
+        # doesn't even have to be reachable
+        s.connect(('10.255.255.255', 1))
+        IP = s.getsockname()[0]
+    except:
+        IP = '127.0.0.1'
+    finally:
+        s.close()
+    return IP
+
+def testPort(ip, port, timeout=0.3):
+        try:
+            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            s.settimeout(timeout)
+            s.connect((ip, port))
+            return 1
+        except(socket.timeout,socket.error):
+            return 0
+
+def esuFind():
+   defaultIP = get_ip()
+   o1,o2,o3,o4 = defaultIP.split('.')
+   print "Starting Scan"
+   for i in range(0,254):
+      scanIP = "%s.%s.%s.%d" % (o1, o2, o3, i)
+      result = testPort(scanIP, 15471, 0.01)
+      if result:
+         print "IP %s has ESU port open" % (scanIP)
+         return scanIP
+   return None
+