--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/zb.py	Sun Oct 28 20:24:28 2007 +1030
@@ -0,0 +1,72 @@
+import serial, struct
+
+s = serial.Serial(port='/dev/cuad0', baudrate=9600, bytesize=8, parity='N', \
+		  stopbits=1, rtscts=0)
+s.setTimeout(0.1)
+#s.write('+++')
+#s.readline(eol='\r')
+
+testdata = ['~', '\x00', '\n', '\x83', '\x00', '\x01', '$', '\x00', '\x01', '\x00', '\x0f', '\x00', '\x07', '@', '~', '\x00', '\n', '\x83', '\x00', '\x01', '$', '\x00', '\x01', '\x00', '\x0f', '\x00', '\x0f', '8']
+
+def readpkt(s):
+    l = []
+    while (1):
+        a = s.read()
+        if (a == ''):
+            break
+        l.append(a)
+    
+    return l
+
+class Packet:
+    def __init__(self):
+        pass
+
+class unPacker:
+    def __init__(self):
+        self.buffer = []
+        self.state = 'init'
+        self.packets = []
+
+        self.bufmsb = 0
+        self.dataleft = 0
+        
+        self.fr_err = 0 # Framing error
+        self.ck_err = 0 # Checksum error
+        
+    def process(self, data):
+        for d in data:
+            dint = struct.unpack('B', d)[0]
+            if (self.state == 'init'):
+                if (d != '\x7e'):
+                    print "Framing error, got 0x%02x, expected 0x7f" % (dint)
+                    self.fr_err = self.fr_err + 1
+                    continue
+
+                self.state = 'sizemsb'
+            elif (self.state == 'sizemsb'):
+                self.bufmsb = dint
+                self.state = 'sizelsb'
+            elif (self.state == 'sizelsb'):
+                self.dataleft = self.bufmsb << 8 | \
+                                dint
+                self.state = 'data'
+            elif (self.state == 'data'):
+                self.buffer.append(dint)
+                self.dataleft = self.dataleft - 1
+                if (self.dataleft == 0):
+                    self.state = 'cksum'
+            elif (self.state == 'cksum'):
+                pktsum = reduce(lambda x, y: x + y, self.buffer) & 0xff
+                rxcksum = dint
+                if (pktsum + rxcksum != 0xff):
+                    self.ck_err = self.ck_err + 1
+                    print "Checksum error, got 0x%02x, expected 0x%02x" % \
+                          (rxcksum, 0xff - pktsum)
+                else:
+                    print "Got a packet - " + str(self.buffer)
+                    self.state = 'init'
+                    self.buffer = []
+            else:
+                print "Invalid state %s! Resetting" % (self.state)
+                self.state = 'init'