+
+ def writetxbuffer(self,packet,packbuf=0):
+ """Writes the transmit buffer."""
+
+ self.SPItrans([0x40|(packbuf<<1)]+packet);
+
+ def simpleParse(self,packet):
+ dataPt = ord(packet[0]);
+ dataPt2 = ord(packet[1]);
+ # check if we have a standard frame, the msb of the second
+ # nibble will be 1. otherwise it is an extended rame
+ stdCheck = dataPt2 & 0x0f
+ if( stdCheck == 16 ):
+ #arb id is first byte + 3 msb of the 2nd byte
+ dataPt = dataPt<<3 | dataPt2>>5
+ print "Standard Packet \n Arb ID: "+("%d"%dataPt)
+ else:
+ #arb id is first byte + 3 msb + 2 lsb of 2nd byte +
+ # 3rd byte + 4th byte
+ dataPt = dataPt<<3 | dataPt2>>5
+ dataPt = dataPt<<2 | (dataPt2 & 0x03)
+ dataPt = dataPt<<8 | ord(packet[2])
+ dataPt = dataPt<<8 | ord(packet[3])
+ print "Extended Data Frame \n Arb ID: "+("%d"%dataPt)
+
+ #find the dataLength
+ dataPt5 = packet[4]
+ dataLength = dataPt5 & 0x0e
+ print "Data Length: "+("%d"%dataLength)
+ # Print the data packet
+ print "Data:"
+ # Temporary, until correct packets are read
+ if( dataLength > 8 ):
+ dataLength = 8
+ toprint = self.pcket2str(packet[5:12])
+ print toprint
+ # For reading correct packets
+ # if (dataLength > 8 ):
+ # print "Acceptable Length Exceeded"
+ # Data length value should never exceed 8
+ # else:
+ # toprint = self.pcket2str(packet[5:(5+dataLength)])
+ # print toprint
+
+ def txpacket(self,packet):
+ """Transmits a packet through one of the outbound buffers.
+ As usual, the packet should begin with SIDH.
+ For now, only TXB0 is supported."""
+
+ self.writetxbuffer(packet,0);
+ self.MCPrts(TXB0=True);
+
+
+ ############### UTILITY FUNCTIONS #################
+
+ def packet2str(self,packet):
+ """Converts a packet from the internal format to a string."""
+ toprint="";
+ for bar in packet:
+ toprint=toprint+("%02x "%ord(bar))
+ return toprint;
+
+
+ ## This code could be drastica
+ def packet2parsed(self,data):
+ dp1 = ord(data[0])
+ dp2 = ord(data[1])
+ dp5 = ord(data[4])
+
+ packet = {}
+ #get the ide bit. allows us to check to see if we have an extended
+ #frame
+ packet['ide'] = (dp2 & 0x0f)>>3
+ #we have an extended frame
+ if( packet['ide'] != 0):
+ #get lower nibble, last 2 bits
+ eId = dp2 & 0x03
+ eId = eId<<8 | ord(data[2])
+ eId = eId<<8 | ord(data[3])
+ rtr = dp5>>6 & 0x01
+ packet['eID'] = " eID: %06d" %(eId)
+ packet['rtr'] = " rtr: %d" % (rtr)
+
+ else:
+ packet['rtr'] = dp2>>4 & 0x01
+
+
+ # Create the standard ID. from the message
+ packet['sID'] = dp1<<3 | dp2>>5
+ packet['length'] = dp5 & 0x0f
+
+ #generate the data section
+ for i in range(0,length):
+ idx = 5 + i
+ dbidx = 'db%d'%i
+ packet[dbidx] = data[idx]
+
+
+ return packet
+
+