Rusefi on MEG1.1 - anyone interrested?

[nighthunter]

Hi everybody,
i am currently verry happy running rusefi on my Smart Roadster. But i want to integrate the rusefi in the original MEG1.1 casing and maintain all the functionality that the MEG has. But for one it is too much work. Is anyone interrested on helping with this project. When finished it could be used on all smarts that used MEG 1.0 or 1.1 So all Fortwos, Roadsters as an plug and play solution.

Best regards
Igor

[kb1gtt]

What would be required? I've seen pictures of fortwos, but that's about the extent of my knowledge of smart cars. Do you have a schematic, or some kind of description about what the pieces do?

[nighthunter]

I have schematics of the car, this is not a problem,also in my free time im trying to reverse the MEG ECU schematics,. Dash is CAN driven, it has an manual gearbox but it is controlled with two DC motors. Both motors have qadrature encoders. One is for clutch and the second is for gear selecting. The gear selector shaft is connected to a potentiometer as a gear in feedback. Clutch feedback is via shunt current sensing. Currently i started to design a PCB that fits to the original 0 261 205 004, 005 or 006 casing. It uses the Bosch 121pin connectors. One is for engine harness other one is for body connection. It uses DC PWM throttle body and an PHIN pwm controlled alternator, but the alternator has D+ so alt control does not need to be integrated. In the desing i want to reuse as much as posible components from the original MEG ECU (BUZ100SL for transmission H-bridges, PWM throttle H-bridge, CJ920 for outputs, 30057 darlingtons for igtion coils.
Some parameters of the engine: 3cyl, 60-2 trigger, VR sensing for engine RPMs and Output speed, 6 coils (twinspark configuration, but firing of coils on one cylinder is a little delayed, 2.5ms dwell at 1000rpms, MAP, turbo, secondary air pump,two NBO2s, DC PWM throttle lbody). Currently i am running "piggybacked" so i use the throttle body feedback potentiometer output as an pedal input for rusefi, but it has disadvantage, as the torque limiting features, etc. influences the rusefi pedal input. I want to use the new design as a plug-and-play swap of the original ECU.

[kb1gtt]

For the current shunt amplifier, you might want to look at ACS line of of hall current sensors. They simplify the current sensing as they are low internal resistance. See below page about the ACS709 which can be obtained for fairly small money.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H1.Xacs+current+sensor.TRS0&_nkw=acs+current+sensor&_sacat=0

See more options found here http://www.allegromicro.com/en/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-Sensor-ICs.aspx

[nighthunter]

Here are hires scans of the MEG ECU, just to make a picture of the original circuitry. Connectors are desoldered also the CJ911 and 30057 are desoldered.
MEGhiresscan.rar - 87.0 MB

In short time ill upload wirings and other materials.

[nighthunter]

Here are files from the wiring diagrams
CJ920 on this ECU is routed to following ECU connector pins:
The ics on the board marking:
B57914 - 8x1 analog MUX 74HCT4351 with latch
B57965 - 74HC14D
B57566 - 74HCT32D?


A1 - EV1
A2 - PIN48 EUVB catalytic converter switch valve
A3 - EV2
A4 - EV3
A5 - PIN89 TEV fuel tank valve
A6 - PIN68 ALTWG wastegate turbocharger
A7 - PIN104
A8 - PIN67 LSHVK
A9 - PIN97 EKPR electronic fuel pump control
A10- PIN66 LSHHK
A11- PIN112 GER blower relay
A12- PIN111 ASGR transmission relay control
A13- PIN113 KOR air conditioner relay
A14- PIN105 ANR starter relay

[kb1gtt]

Most people don't know that you can open PCBNew directly and then PCBNew will then allow you to open PCB files with out the project file. In the future if you could post the full KICAD files that would make it easier for people to view them.

Also KICAD can import a DXF file. KICAD's 2D drawing tools are weak. You could draw up your board outline in something like FreeCAD or some other CAD package which is much nicer about drawing 2D lines, then you can export from that package to DXF, then import into KICAD. That is a much easier method for dealing with the board outline's. I specifically mentioned FreeCAD because FreeCAD has a macro which allows you to make standard 3D models from your KICAD files. If you're going to learn a CAD tool, might as well be that one such that you also happen to get 3D model capabilities.

About the schematics, a list of numbers does not help me much. I do not know what is connected to anything else.

[nighthunter]

In the wiring diags archive there are tiff files. The first page of the tiffs are abbreviations and component listings, on following pages are schematics. The tiffs are multipage, so multiple pages in one file. I uploaded only the outline for now. In next days i will upload partially drawn schematic with components on PCB file. But for now i am not home and on this comupter i dont have the full Project files here(i will be back in 2 days). I want to reuse the CJ920 Lowside driver circuitry but there are 14 channel from wich some of them are "groupped" by the maximal reverse voltage zener protection. eg. injectors are i think 60V, relays 45V etc.... so i uploaded the original pinning from the ECU, to be sure the injectors will be on propper channels to prevent fast wearing of needles. etc..

[kb1gtt]

I missed the pages on the TIFF. I see them now. Can you convert them to a more usable format? I rotated them, then started making them into PDF's, then I noticed you appear to have redundant images, then my 10 minute window of time expired. I do this stuff in 10 minute windows of time.

If there are redundant images, can you clean those out. If they are not redundant, can you give them different file names. As well it would be handy if the multi pages were spliced such that you have one continuous schematic. Having individual pages is handy for printing, then having them all spliced is handy for PC viewing and diagnostics.

For example, see individual PNG's on this page which are handy for printing.
http://rusefi.com/wiki/index.php?title=Vehicle:Subaru_SVX_1995

Then see the PNG on this page which is much easier to view on a computer screen. This style of schematic is much more helpful for me.
http://rusefi.com/wiki/index.php?title=Vehicle:Audi_A4_2.0T_2006

[nighthunter]

Hi, printing on the terminal wich i use for workshop information has printing locked only to tiff, because of license. It will not print to PDFs, even the redirection does not work. So if you wait a day i will manually convert it to PDFs and rotate it.

[nighthunter]

Hi everybody. I was a bit busy, but i am making progress on this project. In a short time i will post here my progress.

[kb1gtt]

Sounds good, keep us posted.

[nighthunter]

Hi, today i realized one thing, now im have almost 75% of the original ecu pins figured out/reverse engineered the purposes. Instead of making a new PCB, easier would be to swap the original MCU. It is a SAK SAK-C167CR-LM. (TQFP 144pins 0.65pitch, pinout in attachment) ST had a 10F27x series of chips. Someone who is more familiar with STMs 32 series, arent there any "pin compatible" STM32. In meaning of pin compatible i mean that the power pins would be on the same places and in the same package?? It would be a big time saver.

By the way ive done some experiments with CJ911 (30343) and it is a really interresting chip. It integrates a VR amplifier with a safety feature, hardware based it counts the 60-2 trigger pattern and when the pattern does not match or even stands for a defined time it ties a safety reset line, wich is in original ecu connected to throttle H-brigde disable pin.

[kb1gtt]

Does the OEM ECU include potting? Can you un-solder and re-solder a chip? The chances of getting a pin compatible other chip is very un-likely. However an adapter board which then adjust the pinout is likely a possibility. However if this is all potted, then it's pretty much a no go. You need a really clean board when soldering SMT stuff.

Beware specialty chips. If the OEM stops using the chip or makes a new version, then the inventory of the chip will disappear. We have focused on using a chip which is used in several markets such that it has less of a chance of obsolescence and less of a chance of supply chain issues.

[nighthunter]

Dont worry about the resoldering. My everyday job is working with PCBs. I have now on my bench a board with desoldered components, that i used to track all the connections. And i have here about 6 more of this ecus . I think there would be a STM32 wich would suite this board.
But regardless of this "tweak" my work on the new ECU board still continues.

[kb1gtt]

It looks like the SAK-C167CR-LM is 5V, and I know the STM32's we have been using at 3.3V. I think that alone would limit how many STM32's you can choose from. As well I see the external bus controller. I fear that would also make it much more difficult. To me it looks like there isn't much there. I think it has allot of security chips, but it looks like a fairly basic board. Building your own board would likely provide you with the ability to know what is happening at the lower levels. Right now, do you know that there are not revision changes in your 6X ECU's have have laying around? If you made your own board, you'd know exactly what is inside and you would not need to guess.

[AndreyB]

It looks like the SAK-C167CR-LM is 5V, and I know the STM32's we have been using at 3.3V.

I believe this alone would kill the idea of replacing one chip with another.