X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=client%2FGoodFETMCPCAN.py;h=06047ff7ba3941c8e2a43906b6367d31afbcbf0b;hp=e942b42a50512daa30e1e9c6a2b81cc111caa05c;hb=9e8ae94f53616cb9ef75279e21cda0bbcd9f232d;hpb=6de9415b927cc697ec315e9792733427fc031945 diff --git a/client/GoodFETMCPCAN.py b/client/GoodFETMCPCAN.py index e942b42..06047ff 100644 --- a/client/GoodFETMCPCAN.py +++ b/client/GoodFETMCPCAN.py @@ -3,7 +3,14 @@ # # (C) 2012 Travis Goodspeed # -# This code is being rewritten and refactored. You've been warned! +# WORKING COPY +# Currently being updated by Siege Technology's ENGS89 team +# Primary contact: Theodore Sumers +# ADDED FUNCTIONALITY: +# 10.4/41.6/83.3 kHz sniffing +# setbitrate +# debugs on TX and RX packet +# int-based state change reqs for preserving state # # The MCP2515 is a CAN Bus to SPI adapter from Microchip Technology, @@ -15,48 +22,353 @@ import sys, time, string, cStringIO, struct, glob, os; from GoodFETSPI import GoodFETSPI; class GoodFETMCPCAN(GoodFETSPI): + """This class uses the regular SPI app to implement a CAN Bus + adapter on the Goodthopter10 hardware.""" + MCPMODES=["Normal","Sleep","Loopback","Listen-only","Configuration", + "UNKNOWN","UNKNOWN","PowerUp"]; + def MCPsetup(self): """Sets up the ports.""" self.SPIsetup(); self.MCPreset(); #Reset the chip. + # We're going to set some registers, so we must be in config + # mode. + self.MCPreqstatConfiguration(); + # If we don't enable promiscous mode, we'll miss a lot of + # packets. It can be manually disabled later. + #self.poke8(0x60,0xFF); #TODO Does this have any unpleasant side effects? + self.poke8(0x60,0x66); #Wanted FF, but some bits are reserved. + + #Array of supported rates. + MCPrates=[10.4, 41.6, 83.3, 100, 125, 250, 500, 1000]; + def MCPreset(self): """Reset the MCP2515 chip.""" self.SPItrans([0xC0]); + + + ################ SETTING BAUD RATE ################ + + + def MCPsetrate(self,rate=125): + """Sets the data rate in kHz.""" + # Now we need to set the timing registers. See chapter 5 of + # the MCP2515 datasheet to get some clue as to how this + # arithmetic of this works. + + + #STORE the prior status + oldstatus=self.MCPcanstatint(); + print "Setting rate of %i kHz." % rate; + #print "Current state is %s." % self.MCPcanstatstr(); + self.MCPreqstatConfiguration(); + # print "Switched to %s state." % self.MCPcanstatstr(); + + + if rate>41 and rate<42: + # NOT CHECKED: based on kvaser website. + # Sets baud rate for 41.6 kbps + CNF1=0x8e; + CNF2=0xa3; + CNF3=0x05; + elif rate>10 and rate<11: + # NOT CHECKED: based on kvaser website. + # Sets baud rate for 10.4 kbps + CNF1=0xbb; + CNF2=0xa3; + CNF3=0x05; + elif rate==125: + #125 kHz, 16 TQ, not quite as worked out above. + CNF1=0x04; + CNF2=0xB8; + CNF3=0x05; + elif rate==100: + #100 kHz, 20 TQ + CNF1=0x04; + CNF2=0xBA; + CNF3=0x07; + elif rate>83 and rate<83.5: + #83+1/3 kHz, 8 TQ + # 0.04% error from 83.30 + CNF1=0x0E; + CNF2=0x90; + CNF3=0x02; + elif rate==250: + #256 kHz, 20 TQ + CNF1=0x01; + CNF2=0xBA; + CNF3=0x07; + elif rate==500: + #500 kHz, 20 TQ + CNF1=0x00; + CNF2=0xBA; + CNF3=0x07; + elif rate==1000: + #1,000 kHz, 10 TQ + CNF1=0x00; + CNF2=0xA0; + CNF3=0x02; + print "WARNING: Because of chip errata, this probably won't work." + else: + print "Given unsupported rate of %i kHz." % rate; + print "Defaulting to 125kHz."; + CNF1=0x04; + CNF2=0xB8; + CNF3=0x05; + self.poke8(0x2a,CNF1); + self.poke8(0x29,CNF2); + self.poke8(0x28,CNF3); + + # and now return to whatever state we were in before + self.MCPreqstat(oldstatus); + #print "Reverted to %s." % self.MCPcanstatstr(); + + + ################# STATE MANAGEMENT ################## + + def MCPcanstat(self): + """Get the CAN Status.""" + return self.peek8(0x0E); + def MCPcanstatstr(self): + """Read the present status as a string.""" + opmod=self.MCPcanstatint(); + return self.MCPMODES[opmod]; + def MCPcanstatint(self): + """Read present status as an int.""" + return self.MCPcanstat()>>5; + + + def MCPreqstat(self, state): + """Set the CAN state.""" + if state==0: + self.MCPreqstatNormal(); + elif state==1: + self.MCPreqstatSleep(); + elif state==2: + self.MCPreqstatLoopback(); + elif state==3: + self.MCPreqstatListenOnly(); + elif state==4: + self.MCPreqstatConfiguration(); + else: + print "Invalid state entered; defaulting to Listen-Only" + self.MCPreqstatListenOnly(); + def MCPreqstatNormal(self): + """Set the CAN state.""" + state=0x0; + self.MCPbitmodify(0x0F,0xE0,(state<<5)); + def MCPreqstatSleep(self): + """Set the CAN state.""" + state=0x1; + self.MCPbitmodify(0x0F,0xE0,(state<<5)); + def MCPreqstatLoopback(self): + """Set the CAN state.""" + state=0x2; + self.MCPbitmodify(0x0F,0xE0,(state<<5)); + def MCPreqstatListenOnly(self): + """Set the CAN state.""" + state=0x3; + self.MCPbitmodify(0x0F,0xE0,(state<<5)); + def MCPreqstatConfiguration(self): + """Set the CAN state.""" + state=0x4; + self.MCPbitmodify(0x0F,0xE0,(state<<5)); + + #################### RX MANAGEMENT ##################### + def MCPrxstatus(self): """Reads the RX Status by the SPI verb of the same name.""" data=self.SPItrans([0xB0,0x00]); return ord(data[1]); + def MCPreadstatus(self): - """Reads the RX Status by the SPI verb of the same name.""" + """Reads the Read Status by the SPI verb of the same name.""" + #See page 69 of the datasheet for the flag names. data=self.SPItrans([0xA0,0x00]); return ord(data[1]); + + def readrxbuffer(self,packbuf=0): + """Reads the RX buffer. Might have old data.""" + data=self.SPItrans([0x90|(packbuf<<2), + 0x00,0x00, #SID + 0x00,0x00, #EID + 0x00, #DLC + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00 + ]); + + return data[1:len(data)]; + + def fastrxpacket(self): + return self.readrxbuffer(0); + + def rxpacket(self): + """Reads the next incoming packet from either buffer. + Returns None immediately if no packet is waiting.""" + status=self.MCPrxstatus()&0xC0; + if status&0x40: + #Buffer 0 has higher priority. + return self.readrxbuffer(0); + elif status&0x80: + #Buffer 1 has lower priority. + return self.readrxbuffer(1); + else: + return None; + + ################# TX MANAGEMENT ################## + + def MCPrts(self,TXB0=False,TXB1=False,TXB2=False): + """Requests to send one of the transmit buffers.""" + flags=0; + if TXB0: flags=flags|1; + if TXB1: flags=flags|2; + if TXB2: flags=flags|4; + + if flags==0: + print "Warning: Requesting to send no buffer."; + self.SPItrans([0x80|flags]); + + 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 + + def peek8(self,adr): """Read a byte from the given address. Untested.""" data=self.SPItrans([0x03,adr&0xFF,00]); return ord(data[2]); - def poke8(self,adr,val): """Poke a value into RAM. Untested""" self.SPItrans([0x02,adr&0xFF,val&0xFF]); + newval=self.peek8(adr); + if newval!=val: + print "Failed to poke %02x to %02x. Got %02x." % (adr,val,newval); + print "Are you not in idle mode?"; return val; - def rand16(self): - """Read a random 16-bit word.""" - - data=self.EZSPtrans([0x49]); - if data==None: - print "Insufficient random data."; - return 0; - return ord(data[6])+(ord(data[7])<<8); - - def info(self): - """Read the info bytes.""" - print "Ember EM26 Z-Stack SPI Module."; - version=self.EM260spiversion(); - status=self.EM260spistatus(); - print "Version: %i" % (version); - print "Status: %s" % (["dead","alive"][status]); - print "" - self.setVersion(); - print "Node ID: %04x" % (self.getNodeID()); - print "Connected to %2i neighbors." % self.neighborCount(); + def MCPbitmodify(self,adr,mask,data): + """Writes a byte with a mask. Doesn't work for many registers.""" + data=self.SPItrans([0x05,adr&0xFF,mask&0xFF,data&0xFF]); + return ord(data[2]); + +############### DEBUG UTILITIES: STATUS MESSAGES ############## + +# def MCPrxstatusmessage(self): +# """Returns string indicating status of RX buffers""" +# status = self.MCPrxstatus(); +# +# if status < 64: +# print "No RX message"; +# elif status < 128: +# print "Message in RXB0"; +# elif status < 192: +# print "Message in RXB1"; +# else: +# print "Messages in both buffers"; + + + +# TXB0TRL = 0x30 +# RXB0CTRL = 0x60 +# CNF3/2/1 = 0x28, 29, 2a +# CANINTE = 0x2b +# CANINTF = 0x2c +# TXRTSCTRL = x0D + + +