Area Representative Purplemeanie Posted August 9, 2019 Area Representative Share Posted August 9, 2019 CharlesElliott, what are you using to do the analysis? What CANbus analyser have you got and what software are you using? I think you mentioned Excel before, but is that what you're using to do the analysis? Link to comment Share on other sites More sharing options...
CharlesElliott Posted August 9, 2019 Share Posted August 9, 2019 It's a Race Technology DL1 data logger which is what I use to log data in my race car. Software is Race Technology Analysis. The most recent screen shot is it just logging raw CANbus. The screenshots above that configure how to translate the raw into displayed. I used Excel to work out the right encoding (byte order, bit order, scaling) to translate to the display. Link to comment Share on other sites More sharing options...
Area Representative Purplemeanie Posted August 9, 2019 Area Representative Share Posted August 9, 2019 Thanks Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 9, 2019 Share Posted August 9, 2019 So it seems from info in the EC2 config files, there are up to 8 data logging channels per CANbus message:__________________________________________________________________________________________________________[English|Data Logging|CAN] Information = This section is used to set up parameters for the data logging link over Can. 1DCANLOGGINGIDENTIFIERTYPE, Identifier Type, Identifier Type, Configure the CAN Data Logging Interface, DISABLED 1DCANLOGGING29BITID, Message Identifier, Message Identifier, Select a Message identifier, DISABLED 1DCANLOGGING11BITID, 11 Bit Identifier, 11 Bit Identifier, Select a 11 Bit identifier, DISABLED 1DCANLOGGINGNUMCHANNELS, Can Number of Channels, Can Number of Channels, Set the number of logging channels (up to 8), DISABLED 1DCANMESSAGE0DATA1, Mess 0 Data 1, Mess 0 Data 1, Mess 0 Data 1, DISABLED 1DCANMESSAGE0DATA2, Mess 0 Data 2, Mess 0 Data 2, Mess 0 Data 2, DISABLED 1DCANMESSAGE0DATA3, Mess 0 Data 3, Mess 0 Data 3, Mess 0 Data 3, DISABLED 1DCANMESSAGE0DATA4, Mess 0 Data 4, Mess 0 Data 4, Mess 0 Data 4, DISABLED 1DCANMESSAGE0DATA5, Mess 0 Data 5, Mess 0 Data 5, Mess 0 Data 5, DISABLED 1DCANMESSAGE0DATA6, Mess 0 Data 6, Mess 0 Data 6, Mess 0 Data 6, DISABLED 1DCANMESSAGE0DATA7, Mess 0 Data 7, Mess 0 Data 7, Mess 0 Data 7, DISABLED 1DCANMESSAGE0DATA8, Mess 0 Data 8, Mess 0 Data 8, Mess 0 Data 8, DISABLED 1DCANMESSAGE1DATA1, Mess 1 Data 1, Mess 1 Data 1, Mess 1 Data 1, DISABLED 1DCANMESSAGE1DATA2, Mess 1 Data 2, Mess 1 Data 2, Mess 1 Data 2, DISABLED 1DCANMESSAGE1DATA3, Mess 1 Data 3, Mess 1 Data 3, Mess 1 Data 3, DISABLED 1DCANMESSAGE1DATA4, Mess 1 Data 4, Mess 1 Data 4, Mess 1 Data 4, DISABLED 1DCANMESSAGE1DATA5, Mess 1 Data 5, Mess 1 Data 5, Mess 1 Data 5, DISABLED 1DCANMESSAGE1DATA6, Mess 1 Data 6, Mess 1 Data 6, Mess 1 Data 6, DISABLED 1DCANMESSAGE1DATA7, Mess 1 Data 7, Mess 1 Data 7, Mess 1 Data 7, DISABLED 1DCANMESSAGE1DATA8, Mess 1 Data 8, Mess 1 Data 8, Mess 1 Data 8, DISABLED__________________________________________________________________________________________________________The problem now is to determine the bit offsets and bit widths for each channel, there are "SCALING" and "STRING" parameters in the config files that seem to relate to the bit configuration for the parameters, I will have a look at these after work, later today.The message frequency is likely 12.8Hz / 78ms interval, as found by Charles and from Mark's initial dump. Link to comment Share on other sites More sharing options...
CtrMint Posted August 9, 2019 Author Share Posted August 9, 2019 Guys,I've been spending a lot of time looking how to make the development practical, mostly to avoid being in the garage hooked up to the car! I've got a useful solution with respect to socketCan which both John and I are using. socketCan supports a virtual canbus interface, vcan, and of course it doesn't need to be connected. You can replay traffic at vcan and into any tools, which Wireshark will also see.To replay use canplayer, you need to tell canplayer to fake the original source interface with the vcan instance.canplayer -I candump-2019-08-08_140704.log vcan0=can0In the above example candump-2019-08... is a standard non human readable log file from candump.In theory you can record a lengthy candump with the engine running and keep replaying it while working to decode the data or write a new tool/dash.Setting up the vcan is as follows;sudo modprobe vcan sudo ip link add dev vcan0 type vcan sudo ip link set up vcan0 Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 9, 2019 Share Posted August 9, 2019 So, a bit more digging in Easimap. In 'System' 'Can Datastream' 'Setup' on my unlocked 9A4 ECU, all the CAN mappings are configurable with this screen (can someone look at their locked ECU to see if this is configurable? I suspect not, as it should require an ECC write to save):There are two possible 29-bit CANbus IDs that can be set (CBB0001 & CBF1234) and up to 8 data stream messages, of which I have 3 configured at the moment, but these are not necessarily what the MBE985 adapter is using, as my CANbus config doesn't include many of the data channels I currently receive using this config via Easimap. The menu dropdown on the right is the list of selectable values that can occupy each of the seven configurable data blocks in the message (the first of the eight data blocks being reserved for the MBE message identifier). Link to comment Share on other sites More sharing options...
CtrMint Posted August 9, 2019 Author Share Posted August 9, 2019 Thanks for that James, that's really helpful. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 9, 2019 Share Posted August 9, 2019 A bit more info, it looks like all 8 potential messages are used cyclically. If we break them down into the 8x8 matrix (8 messages with 8 data cells) and reverse the order in part of your dump, this is what we see:01 4F 00 00 3D 00 9C 46 02 00 00 00 AF D5 00 00 03 27 00 1E 00 00 00 00 04 9C FF 28 00 00 00 00 FF 9C 00 00 00 00 00 00 FF 46 00 00 00 00 00 00 FF 00 00 00 00 00 00 00 FF 00 00 00 00 00 00 00You seem to have messages 1-4 in use (01, 02, 03, 04 in the first byte of the message) and messages 5-8 are not used, as they have an undefined value of 255 set. In this case 12 of the data bytes / cells seem to contain data, each cell capable of 256 different values. I think things like engine RPM where it can be configured with a 'high' and 'low' value would be capable of 65536 values when spread over two data bytes / cells.Looking at the 184 useful messages in your 3.5 second dump, there are some static values (likely temperature readings and other slow changing values) and a number of dynamic fields (perhaps throttle, engine RPM if running and voltages). Addressing as a matrix (Message number 1-8, data field 0-7 where 0 is the message number) and expressing the value as an integer from 0 to 255:(1,1) constant at 79(1,6) constant at 156(1,7) constant at 70(2,5) constant at 213(3,1) constant at 39(4,1) constant at 156(4,2) constant at 255(4,3) constant at 40(1,4) variable from 65 to 211(1,5) variable from 0 to 231(2,4) variable with discrete values of 7F, 8F, 9F, AF, BF, CF, DF & EF in roughly equal occurrences, seems like a status change set in the first octet.(3,3) variable from 0 to 95.This is what the variable values look like plotted, almost like half a dozen rapid throttle blips:I think the next step would be to correlate a CANbus dump with an Easimap logging session, it should then be possible to align data elements and their scaling and determine what values are included in the four CANbus messages the ECU publishes. Link to comment Share on other sites More sharing options...
CharlesElliott Posted August 10, 2019 Share Posted August 10, 2019 The CAN config is neither editable nor viewable on a locked ECU. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 10, 2019 Share Posted August 10, 2019 The Race Technology view of 9A4 or 992 CAN config looks similar to my ECU, but not the same. It does give useful info on resolution, though, but I’m not sure how single byte voltage values can have 0.01V resolution with a range more than 2.55V: https://www.race-technology.com/wiki/index.php/ECUType/MBE9A4AndMBE992CAN Link to comment Share on other sites More sharing options...
CtrMint Posted August 10, 2019 Author Share Posted August 10, 2019 "can someone look at their locked ECU to see if this is configurable?"I've had a good look and unfortunately not, also it seems impossible to view the baseline setup. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 10, 2019 Share Posted August 10, 2019 Time for one of these I think, Mark: https://www.amazon.co.uk/Kingzer-Splitter-Extension-Cable-Female/dp/B000TMCX72i don’t think implying my config of my non-Caterham supplied 9A4 will help in decoding your locked config, but 10 mins of data collection from a cold start with varied driving, into Excel spreadsheets of both the CAN data and the Easimap dump (at 20ms dump resolution for the Excel export) and I think it would be easy to correlate each data cell.I also expect that the CAN config that Caterham uses may not include all the possible elements, but having a dozen or so is still worthwhile. Link to comment Share on other sites More sharing options...
Tony Leigh Posted August 10, 2019 Share Posted August 10, 2019 I am finding this post interesting, but it is way above my understanding on the IT side. I can see how it would be really useful to see what data the ECU is transmitting. I wonder how much it costs to get password access via CC. I believe one of the posts mentioned this was an option. Just wondering if anyone knew, as using and configuring all the kit Mark has mentioned sounds like it’s starting to get quite expensive. Good luck with your continuing quest. I will read with interest but unfortunately I can’t add any advice/expertise. Link to comment Share on other sites More sharing options...
Area Representative Purplemeanie Posted August 10, 2019 Area Representative Share Posted August 10, 2019 Ok, so hopefully I can move this on a small amount...I've now got both Easimap running and a CANBus sniffer. The setup is: MacBookPro running Easimap through Parallels,Windows 10 VM SBD USB to CANBus interface connected to Mac and the USB routed through to the Windows VM Raspberry Pi 4 with a PiCAN2 HAT OBD-II Y-cable plugged into Caterham, MacBookPro (Easimap) and Pi (PiCAN2 running tshark) Ignition set to postion 2 but engine not running (I'll try some running tests when I've (we've) firgured out some more of what's going onHere's a picture of the setup:I've tried a few captures of what's going on when Easimap is running with the following findings: Until easimap is running the car outputs CAN packets as per Marks output on page 3 of this thread (all the packets are coming from a device with an ID of 0x0cbb001) Once Easimap is started there are two new devices that start talking on the bus 0xcbe1101 - seems to be the SBD USB to CANBus interface 0xcbe0111 - seems to be another device in the car, probably where Easimap is getting its data from It seems that Easimap is sending a packet with 0x(03,04,00,0d,ef,fb,ff,f7) which starts the 0xcbe0111 device sending.I also tried turning the car off to see what Easimap would do then. It then starts sending packets out at about 1s intervals with the values 0x(03,04,00,0d,cf,00,00,e2). That's what makes me think that 0xcbe1101 is the SBD interface and that it sends a 03,04... packet to get the car to output more info.My suspicion is that the 03,04 packet is opening a CAN gateway in the car. I now have a lot more data, but still no idea what it means.Here's a chunk of data from Wireshark at around the time that Easimap starts to talk to the car, the initial Easimap packet seems to be at packet 528 (left column):No. Time Protocol Length Info 522 5.217999920 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 523 5.227903970 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 524 5.237803910 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 cf d6 00 00 525 5.248304747 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 526 5.257841952 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 527 5.267871945 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 528 5.269606548 CAN 32 XTD: 0x0cbe1101 03 04 00 0d ef fb ff f7 529 5.270596810 CAN 32 XTD: 0x0cbe0111 10 0d e4 00 0d 23 39 41 530 5.270927046 CAN 32 XTD: 0x0cbe0111 21 34 62 65 35 33 30 00 531 5.277878771 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 532 5.288061077 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 533 5.297965424 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 534 5.308121693 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 535 5.318314165 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 cf d6 00 00 536 5.328443119 CAN 32 XTD: 0x0cbe1101 03 04 00 5e ef fb ff f7 537 5.328729670 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 538 5.329432159 CAN 32 XTD: 0x0cbe0111 07 e4 00 5e 2b 07 01 00 539 5.337934713 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 540 5.347971169 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 541 5.357984570 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 542 5.368106561 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 543 5.378248386 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 544 5.388638336 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 545 5.398827049 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 9f d6 00 00 546 5.408066758 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 547 5.418108103 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 548 5.428370518 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 549 5.438262384 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 550 5.448232693 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 551 5.459009322 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 552 5.468146959 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 553 5.478194340 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 ef d6 00 00 554 5.488435460 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 555 5.498216679 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 556 5.508246450 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 557 5.518649382 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 558 5.528866409 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 559 5.538409909 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 560 5.548303645 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 561 5.558352749 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 bf d6 00 00 562 5.568327299 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 563 5.578379125 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 564 5.588759816 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 565 5.599091804 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 566 5.608444419 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 567 5.618418746 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 568 5.628551367 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 569 5.638437603 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 8f d6 00 00 570 5.648491596 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 571 5.658657346 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 572 5.669189776 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 573 5.678610186 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 574 5.688548625 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 575 5.698673153 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 576 5.708593426 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 577 5.718837841 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 ef d6 00 00 578 5.729158163 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 579 5.738714219 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 580 5.748656584 CAN 32 XTD: 0x0cbb0001 ff 00 00 00 00 00 00 00 581 5.758626393 CAN 32 XTD: 0x0cbb0001 ff 49 00 00 00 00 00 00 582 5.768961752 CAN 32 XTD: 0x0cbb0001 ff 95 00 00 00 00 00 00 583 5.776471191 CAN 32 XTD: 0x0cbe1101 10 0a 01 00 00 00 00 12 584 5.777320493 CAN 32 XTD: 0x0cbe1101 21 66 67 a8 a9 00 00 12 585 5.778524474 CAN 32 XTD: 0x0cbe0111 05 81 aa aa 16 00 12 66 586 5.778809858 CAN 32 XTD: 0x0cbb0001 04 95 ff 28 00 00 00 00 587 5.787125934 CAN 32 XTD: 0x0cbe1101 10 09 01 00 00 00 00 1a 588 5.787834886 CAN 32 XTD: 0x0cbe1101 21 52 5c 5d 00 00 00 1a 589 5.788834463 CAN 32 XTD: 0x0cbe0111 04 81 84 00 00 00 1a 52 590 5.789118458 CAN 32 XTD: 0x0cbb0001 03 27 00 1d 00 1d 00 00 591 5.799340004 CAN 32 XTD: 0x0cbb0001 02 aa aa 00 bf d6 00 00 592 5.800358840 CAN 32 XTD: 0x0cbe1101 10 0a 01 00 00 00 00 e2 593 5.801094588 CAN 32 XTD: 0x0cbe1101 21 cc cd ce cf 00 00 e2 594 5.802136776 CAN 32 XTD: 0x0cbe0111 05 81 ff ff ff 07 e2 cc 595 5.808806413 CAN 32 XTD: 0x0cbb0001 01 52 00 00 39 00 95 49 596 5.814872560 CAN 32 XTD: 0x0cbe1101 10 23 01 00 00 00 00 f8 597 5.815639382 CAN 32 XTD: 0x0cbe1101 21 30 31 36 37 44 45 4c 598 5.816393407 CAN 32 XTD: 0x0cbe1101 22 4d 4e 4f 50 51 5a 5b 599 5.817143414 CAN 32 XTD: 0x0cbe1101 23 5c 5d 64 6a 6b 7c 7d 600 5.817903458 CAN 32 XTD: 0x0cbe1101 24 9e 9f a0 a1 d8 d9 da Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 10, 2019 Share Posted August 10, 2019 Is it possible to collect about 10 mins of CAN data with some rev variation in there as the engine warms up (or at least sees some variation in the logged temperatures), along with the corresponding Easimap log file via the 'logging' 'export to spreadsheet' with at 20ms 'fixed time axis interval'? Probably will create about 5MB of Easimap CSV and 10MB of CAN logging data. Link to comment Share on other sites More sharing options...
Area Representative Purplemeanie Posted August 10, 2019 Area Representative Share Posted August 10, 2019 Hi James, that should be possible. I may need to wait for the weather to clear and be able to get the car out of the garage :-)Do you want the CAN data in any particular format? I've only used tshark (Wireshark) to capture packets so far, and the associated .pcap can be a little difficult to work with - though libpcap programming isn't too bad its not easy to dump pcap's into something like Excel.Can you tell me what you're going to do with the data and then hopefully I can make sure it works as best as I can make it for you. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 10, 2019 Share Posted August 10, 2019 If you can output (or pipe STDOUT from Wireshark) in to a txt file the same format as you have used here for the CAN data, that would be good and save me having to parse the .pcap file. The Easimap 'export to spreadsheet' function will create a CSV file with a header and each row containing all logged parameters. If you could add all relevant panels with the associated realtime channel to the Easimap display page, then after saving the logging session file .LSN, export that with 20ms interval, that would be good.What I will do with the data is crunch each line in each of the CAN .TXT and Easimap .CSV files, sort to extract the up to 28 data field in the CAN messages (there seem to be 4 active messages each capable of holding 7 data fields), convert from hex to dec and graph patterns that will then be matched with the pattern for each channel in the .CSV file. When a pattern is found, the values from the CSV file can then be matched with the bit pattern in the .TXT file to evaluate range and scaling.When logging it would be good to have several intervals of about 30 seconds in the 10 min or so capture that have the car idling, so I can use these as reference alignment points to synchronise the timestamps in the two files.I'm able to do some crunching until later tomorrow, then travelling to Montreal for work until late Thurs, so won't have access to all my tools for data manipulation at the bit-level while away, but hopefully the files are small enough for emailing so I might be able to get started while away, I will PM you my email address. I do have the ability to access files on Google Drive and Box, as well. Link to comment Share on other sites More sharing options...
CtrMint Posted August 10, 2019 Author Share Posted August 10, 2019 Brilliant work John! You beat me to it sourcing a Y cable, I've got mine on order, so hopefully it will arrive next week, but its good to know it works as expected!I'm wondering if the packet 0x(03,04,00,0d,ef,fb,ff,f7) is essentially the following from the EC2 file."1D_DATALOGGERLINK, Data Logger Link, Data Logger Link, Enables and disables serial datastreaming from the ECU."It would be interesting to see if simply replicating the packet with cansend will trick the ECU into transmitting.Any you could send me the pcap. Link to comment Share on other sites More sharing options...
Area Representative Purplemeanie Posted August 10, 2019 Area Representative Share Posted August 10, 2019 For anyone interested, here are two .pcap files...The first is the pcap that generated the packet listing in post #64 above:https://www.dropbox.com/s/29vkmdltab3ytm3/cano-003-ig2_0s-easimap_1000p.pcap?dl=0The second pcap is a simple capture of what was on the CAN bus with just Easimap looking for an ECU to monitor:https://www.dropbox.com/s/07i02ojv9lsum2z/cano-004-only-easimap.pcap?dl=0Knock yourself out! :-)(I'm currently trying to figure out if there's a mapping between what's in the can bus data and what's in the Easimap EC2 file. I'm sure there must be a correlation between the can bus data and the page/address config from the EC2. There are some correlations but I haven't got the confidence yet that I've figured it out.)And Mark, I also think there's a good chance that replaying the 0x(03,04...) packet into the canbus may just wake up the gateway that's hiding the second CAN ID. But Easimap is a little chatty around that time so it might take a few of those codes around pkt 528 in that pcap. One of my next experiments is to see what Easimap does if it's running but the car is off, then I turn the car on. I'm wondering if Easimap turns the 0x(03,04,00,0d,cf,00,00,e2) into 0x(03,04,00,0d,ef,fb,ff,f7) or is the first data set enough to wake things up.I'm definitely still poking around in the dark, but at least we now have a torch!John Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 10, 2019 Share Posted August 10, 2019 In terms of what is in the CANbus data and mapping in the .EC2 file, the datafields in the message are defined, but it seems that the .ECC file contains the configured mappings from the specific sensor data element to the message datafield, which you can't determine in the locked ECU. This is where I believe that I can reverse engineer that mapping from comparing the Easimap data elements to the CANbus message datafields. There may be other ways, but scanning through the Easimap binaries and config files hasn't given me any other clues yet. Link to comment Share on other sites More sharing options...
CtrMint Posted August 10, 2019 Author Share Posted August 10, 2019 I'm just looking through John's data, I've converted the pcap to candump format if anyone wants a copy.It occurs to me rather than try and decode blind etc, wouldn't it be easier to replay each single message on the bus with the ignition off, but with Easymap connected. Then watch the reaction in Easymap. If a byte in a given message generates a change in an Easymap value then we've found the source byte. It's then a case of stepping through increments to try and work out the scale etc. This could be done by programmatically stepping through increments and comparing against the Easymap log file. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted August 10, 2019 Share Posted August 10, 2019 That would narrow down the fields if you can cause one value to change at a time. Link to comment Share on other sites More sharing options...
CtrMint Posted August 10, 2019 Author Share Posted August 10, 2019 John,I notice the Pican2Hat is socketCan compatible, it should be trivial to replay messages at your Easymap software if you wire your CANH and CANL hat pins to the respective pins on the cable, suspect you'll need the 120ohm resistor in place. In theory, you can avoid the car and control Easymap.Nice on the Pi4... still need to sort mine. Link to comment Share on other sites More sharing options...
Area Representative Purplemeanie Posted August 10, 2019 Area Representative Share Posted August 10, 2019 That would certainly be worth a try Mark.Can you put up the converted candump formatted file somewhere?How did you convert it? Have you got some custom code in Wireshark or have you written a libpcap based converter? I was thinking of just parsing an exported CSV file from Wireshark, but that's not very elegant :-)John Link to comment Share on other sites More sharing options...
CtrMint Posted August 10, 2019 Author Share Posted August 10, 2019 Sure I'll put in on dropbox. Although my conversion wasn't that fancy.I exported the pcap from Wireshark to file, you get something like the following for each packet, so the file looks pretty unusable.However I simply grepped the file for each line with 'CAN' and then used awk to recreate each line in the candump format.grep CAN export1.txt | awk '{print "("$2")" " can0 " $6"#"$7$8$9$10$11$12$13$14 }' > pcap_as_candump.txt Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now