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MEVD17.2 emulation in development

Discussion in 'N55' started by LamboLover, Oct 31, 2017.

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  1. Sbrach

    Sbrach Corporal

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    167
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    N55 DCT E82
    So are you planning to integrate with MHD or roll your own logger? Or are neither of those in scope? The resolution this would allow would be great.
     
  2. LamboLover

    LamboLover Corporal

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    It is a multiplatform interface, just trying to get the basics going on all the comms layers by testing each part hard as I go. The ECU is ready to run very fast logging, it would be a case of sending the RAM addresses to log to it and processing the stuff returned. I didn't do it with J2534/TunerProRT as they are really setup for single rate logging whereas the ECU sends at 350 Hz, 100Hz and 10Hz. If I get the microcontroller to reassemble them and create a logging row it should jive well with how TunerProRT likes its data.
     
  3. dzid_

    dzid_ Lurker

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    11
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    US
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    135i 2011 DCT
  4. LamboLover

    LamboLover Corporal

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    That looks like a nice device, reasonably priced. The usual problem is that the firmware and CPU is not fast enough, but if it is actually J2534 compliant it should be very good. The problem is that a lot of J2534 stuff doesn't stick to the specs. The gateway already has CAN H and L, so you can use them for KWP2000 on CAN through the OBD port. It won't give you all the stuff that is transmitted on PT-CAN but you can request what you want. Edit - the CPU does look good although the one I'm using is 5 times faster and has 16 times the flash memory. Sources are on Github too so that is promising to tweak it to your needs.
     
    Last edited: Jul 24, 2018
  5. doublespaces

    doublespaces Administrator

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    6,253
    Location:
    AZ
    Ride:
    2009 E93 335i
    Ah, I love it when good hardware is used. Who likes 'base model' electronics anyway
     
  6. LamboLover

    LamboLover Corporal

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    upload_2018-8-6_20-16-4.png Finished the ISO 15765 debugging and testing (aimed at flashing and logging).

    Added BMW specific TCP comms format to do the above with extended addressing to suit KWP over CAN and UDS over CAN, with backward compatibility for K line (not yet implemented but part of the hardware design), support for 4095 byte UDS frames (16 times bigger than present 8 bit DCAN cables with consequent massive increase in performance). Performance is close to Ethernet, but this is using CAN which has a far wider audience.

    Made J2534 driver for plain CAN frames to satisfy one of the original purposes of a new physical device: to allow realtime tuning without having to buy in expensive J2534 cables. This works over WiFi, performance is in between the Kvaser and OpenPort 2.0 USB cables you can see in the selection window above. Both of these are $200-300 and the cheapest good J2534 devices - the Chinese copies are unreliable and slow.

    I have four prototype OBD devices stuck in customs. These have a different internal physical arrangement to join the two boards together to fit in the small enclosure. They also have 16MB external flash, but subsequent revisions will have this on the module itself and will have 4MB external RAM instead of existing 512KB which is enough to play DOOM (no display included ;) ), or hold a flash image to operate on in one session. Doesn't sound much, but a recent DCAN solution has 3.5KB of RAM.

    The only testing done by the electronic engineer is to see they do not let out smoke and throw some stuff out on serial when powered, so lots of functional testing to do, but very exciting seeing it come together.
     
    Last edited: Aug 6, 2018
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  7. jyamona

    jyamona Lieutenant Vendor

    Messages:
    553
    Location:
    Philly
    Keep up the great work John. Will take one of those prototype devices off your hands too ;)
     
  8. Tigger2011

    Tigger2011 New Member

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    1
    Ride:
    Mini Cooper
    Wow. I'm speechless at the phenomenal amount of work you've put into this. Bravo sir, bravo.
     
  9. LamboLover

    LamboLover Corporal

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    Prototypes arrived Thursday, but they were untested and had hardware problems. New designs done and ordered and the electronic engineer will test this time.

    The firmware for this is a huge task so I had arranged an expert to do the layout so I could concentrate on firmware.

    Let's hope the expert delivers this time.
     
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