X-Git-Url: http://git.rot13.org//?p=goodfet;a=blobdiff_plain;f=client%2FGoodFETMCPCAN.py;fp=client%2FGoodFETMCPCAN.py;h=3b4a63afcef6401ecfe0b68ecece76dcddb0e60b;hp=7182d3706d7e9cf80a5a8d0f296aa78649aeb871;hb=9a80a19cb770d327da52ec6d04ad0fc564f62270;hpb=367188d60f5a37dd9847aaf3b8efc442db4415dd diff --git a/client/GoodFETMCPCAN.py b/client/GoodFETMCPCAN.py index 7182d37..3b4a63a 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, @@ -19,11 +26,11 @@ class GoodFETMCPCAN(GoodFETSPI): 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(); @@ -32,55 +39,46 @@ class GoodFETMCPCAN(GoodFETSPI): # 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. - - #Set the default rate. - self.MCPsetrate(); - + #Array of supported rates. - MCPrates=[83.3, 100, 125, - 250, 500, 1000]; + 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, as my comments here will likely be - # rambling, incoherent, and unchanged after I get the infernal - # thing working. - - # First, we must chose a Time Quanta (QT) which is used to - # define the durations of these segments. Section 5.3 - # suggests setting BRP<5:0> to 0x04 to get a TQ=500ns, as a 20 - # MHz crystal gives a clock period of 50ns. This way, for 125 - # kHz communication, the bit time must be 16 TQ. - - # A bit consists of four parts: - # 1: SyncSeg 1 TQ - # 2: PropSeg 2 TQ - # 3: PhaseSeg1 (PS1) 7 TQ - # 4: PhaseSeg2 (PS2) 6 TQ - - # CNF1 with a prescaler of 4 and a SJW of 1 TQ. SJW of 4 - # might be more stable. - #self.poke8(0x2a,0x04); - - # CNF2 with a BLTMODE of 1, SAM of 0, PS1 of 7TQ, and PRSEG of 2TQ - #self.poke8(0x29, - # 0x80 | # BTLMODE=1 - # (6<<3) | # 6+1=7TQ for PHSEG1 - # (1) # 1+1=2TQ for PRSEG - # ); - - #CNF3 with a PS2 length of 6TQ. - #self.poke8(0x28, - # 5 #5+1=6TQ - # ); - + # 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(); + - #These are the new examples. - if rate==125: + 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; @@ -121,13 +119,41 @@ class GoodFETMCPCAN(GoodFETSPI): self.poke8(0x2a,CNF1); self.poke8(0x29,CNF2); self.poke8(0x28,CNF3); - - def MCPreset(self): - """Reset the MCP2515 chip.""" - self.SPItrans([0xC0]); + + # 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; @@ -149,11 +175,8 @@ class GoodFETMCPCAN(GoodFETSPI): state=0x4; self.MCPbitmodify(0x0F,0xE0,(state<<5)); - def MCPcanstatstr(self): - """Read the present status as a string.""" - status=self.MCPcanstat(); - opmod=(status&0xE0)>>5; - return self.MCPMODES[opmod]; + #################### RX MANAGEMENT ##################### + def MCPrxstatus(self): """Reads the RX Status by the SPI verb of the same name.""" data=self.SPItrans([0xB0,0x00]); @@ -161,38 +184,25 @@ class GoodFETMCPCAN(GoodFETSPI): def MCPreadstatus(self): """Reads the Read Status by the SPI verb of the same name.""" - #See page 67 of the datasheet for the flag names. + #See page 69 of the datasheet for the flag names. data=self.SPItrans([0xA0,0x00]); return ord(data[1]); - - 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 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 writetxbuffer(self,packet,packbuf=0): - """Writes the transmit buffer.""" - self.SPItrans([0x40|(packbuf<<1)]+packet); + 0x00,0x00, #SID + 0x00,0x00, #EID + 0x00, #DLC + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00 + ]); + return data[1:len(data)]; + def rxpacket(self): """Reads the next incoming packet from either buffer. - Returns None immediately if no packet is waiting.""" + Returns None immediately if no packet is waiting.""" status=self.MCPrxstatus()&0xC0; if status&0x40: #Buffer 0 has higher priority. @@ -202,12 +212,49 @@ class GoodFETMCPCAN(GoodFETSPI): 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."; + if self.MCPcanstat()>>5!=0: + print "Warning: currently in %s mode. NOT in normal mode! May not transmit." %self.MCPcanstatstr(); + self.SPItrans([0x80|flags]); + + def writetxbuffer(self,packet,packbuf=0): + """Writes the transmit buffer.""" + + self.SPItrans([0x40|(packbuf<<1)]+packet); + #READ BACK BUFFER 0 to check what we're about to send out + data=self.SPItrans([0x03, 0x31, + 0x00,0x00, #SID + 0x00,0x00, #EID + 0x00, #DLC + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00 + ]); + print "about to transmit:" + self.packet2str(data[2:len(data)]); + 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.SPItrans([0x81]); self.MCPrts(TXB0=True); + + + ############### UTILITY FUNCTIONS ################# + def packet2str(self,packet): """Converts a packet from the internal format to a string.""" toprint=""; @@ -218,10 +265,6 @@ class GoodFETMCPCAN(GoodFETSPI): """Read a byte from the given address. Untested.""" data=self.SPItrans([0x03,adr&0xFF,00]); return ord(data[2]); - 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]); def poke8(self,adr,val): """Poke a value into RAM. Untested""" self.SPItrans([0x02,adr&0xFF,val&0xFF]); @@ -230,3 +273,34 @@ class GoodFETMCPCAN(GoodFETSPI): print "Failed to poke %02x to %02x. Got %02x." % (adr,val,newval); print "Are you not in idle mode?"; return val; + 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 + + + \ No newline at end of file