[Diy_efi] Microcontroller based Auto Related Projects

Thu Nov 1 20:39:32 UTC 2012

I always like microcontroller projects, have built some interesting things, too. I was considering trying to build an ECU, but then I realized something.  For me; with my project goals, GM had already engineered the perfect ECU. It's so good that millions of them are out there on the road today. Every parameter is configurable and the hardware is bulletproof. So I went with a Delco 1227730 ECU, and focused my microcontroller projects on other areas.  I made projects for where there aren't off-the-shelf, highly cost-effective solutions already available.  I've built auto headlights controller, air-levelling suspension controllers, parts-washer controller, heat pump controller, speedometer calibration modules, and other odds and ends. But the Delco ECU is just too cheap, available, rugged, and just plain good at what it does to re-invent the wheel for an engine ECU. The learning curve was a little steep learning the tuning, because there is SO MUCH in the ECM program. But it was worth it in the end, because it's so configurable.

This is just my OPINION and I hope you guys take it as that. Not meaning to discourage anyone. I wanted to tell about the end result of when I went down the same path and the final decision I came to.

Respectfully,
David
  ----- Original Message ----- 
  From: xyz Q 
  To: diy_efi at diy-efi.org 
  Sent: Thursday, November 01, 2012 3:26 PM
  Subject: Re: [Diy_efi] Microcontroller based Auto Related Projects

  All this is ok. But I'm thinking in order to get started, wouldn't be be good if some experts could hold some basic ruts on this forum. Let's see what some have to say, mainly very specific info eg., rpm counting, etc, etc... But I know time would be a big issue for many.

  I downloaded some notes from Freescale on 68HC08 to introduce me to Motorola MCUs. My only experience is with 80x86 MPU from back in tech school.

  Anyways, here's an offtopic link that some might find useful. It's got premium ebooks on just about every subject for free.

  www.freebookspot.es

  On Nov 1, 2012 1:06 PM, "Alan To" <toalan at 14point7.com> wrote:

    For me 5v operation is a must have so to be able to work with the widest range of sensors possible without additional burden of resistor dividers. The MPC555x is a $30 uC, you are doing some high end stuff, for high end stuff priorities are different, if you need to work with 5v sensors the cost of 0.1% or better tolerance resistors or an external ADC is probably not an issue. Originally we were talking about uCs in the same league as the 8 bit PICs, AVRs, and perhaps as high as ARM Cortex M3/M4.

    Regards

    Alan To

    On 10/31/2012 5:41 AM, Bill Shaw wrote:

      The operating voltage is not a significant decision factor when choosing an automotive microprocessor.  The MPC5554 we are using has a 1.3 volt core and 3.3 volt I/O.  It is an awesome  automotive microprocessor,  but the array of peripherals and registers would be a bit daunting for the uninitiated.

      Best,

      Bill

      On 10/31/2012 12:16 AM, Alan To wrote:

        It is a 3.3v chip and you really want 5v operation for automotive. The new Arduino Due will be a trainwreck, an epic one.

        On 10/30/2012 6:47 PM, xyz Q wrote:

          There's an ARM based Arduino. What would you say about that for a choice?

          On Oct 31, 2012 1:22 PM, "Avery Nisbet" <anisbet at gmail.com> wrote:

            1.  Most of the hack a day projects are by IT/computer sci guys that
            look down on getting their hands dirty with cars. If you look deeply
            at some of the projects they will have really shoty electrical
            engineering in them. Some of them are pure hacks and would not work in
            a production sense.  Some are pretty decent.

            2. Pics from an architecture point of view kinda suck. They were not
            designed for use with stack based compilers(One working register).
            The Motorola stuff was some of the 1st used in the automotive space.
            The architecture lends itself to use with a compiler.  They are
            designed for the harsher automotive environment.  Some will say they
            have nicer hardware peripherals.  I would say some of the peripherals
            were designed specifically for the automotive market. There is also a
            pretty big code base to look at.  Oh and mostly anyone who went to
            school for software or hardware who is older than say 30 was forced to
            learn 6800(68HC11) or 68000 assembly language.  This usually involved
            getting ahold of the purple data books motorola gave away for free
            that were well enough written so you could get your class work or real
            work done. I probably have 2 or 3 copies of the 68HC11 books laying
            around somewhere. This being said there are many other options today
            and I would look to ARM or AVR before I looked at PIC.  ARM is already
            dominating the cheap 32bit market and is pretty easy to pick up. This
            will help in the job search later. AVR's are pretty good for the 8bit
            scene.  GCC supports them and ATMEL makes some automotive environment
            parts.

            3.  Go get yourself an Arduino(or other uC of choice), BIP373(OR GM
            ignition module) and some optoisolators.  Then build a distributor
            and/or crank trigger based ignition system. Then try turning that into
            a full engine management solution using the peak and hold add in board
            by Jbperf. Start researching the mega squirt schematics at the timing
            input(tach) and the ignition output. Build those circuite on a bread
            board and test on a bench. Then move them on to your test engine. It
            could be a lawn mower engine or a V8 monster. Read up on timing
            advance and program the Arduino to do a simple RPM only based timing
            curve.  Then add a MAP and/or TPS sensors and add load as a factor of
            your timing curve.  Then engine temp to add some cold start advantages
            and you have all the sensors needed to do open loop EFI.  After adding
            injectors you could add a wide band O2 sensor such as the LC-1 from
            innovative motor sports or just a heated narrow band for cruze.

            -Avery

            On Mon, Oct 29, 2012 at 8:13 PM, xyz Q <xyzqhtc at gmail.com> wrote:
            > Hi, I've been on the list for some time, on and off mainly reading bits,
            > trying to find some interesting ideas. Unfortunately I was 10 years too
            > late, when this forum had been in its prime.
            >
            > So here are my first set of questions that I hope on getting some answers,
            > hopefully.
            >
            > 1. Why are there so little auto related uc based projects and ideas out
            > there on the net? Look at hackaday.com, for example. Many projects, talented
            > people but all they do is prove a point that some thing can be done. But
            > guess what hardly something is really useful. I may have missed some good
            > worth while so please put them here if you know.
            >
            > 2. If PICs are so popular, why are Motorola MCUs popular with auto projects?
            > In terms of features aren't they on the same "level"?
            >
            > 3. The way I see to learn microcontroller based EMS or ignition is to look
            > at it piece by piece. Megasquirt is great but it's hard to learn a complete
            > system. Aren't there any web sites (I've seen DIYEFI) that have info on say
            > ignition control, RPM handling with an MCU or other basic control concepts
            > that can form the basis for EMS/Ign. related projects. I'd like to learn the
            > basics and if there are specific approaches to this, I'd like to hear your
            > side of the story. It would be helpful.
            >
            > Thanks and regards to all on the forum. Some projects here are really nice
            > and inspiring.
            >
            > Nik.
            >
            > _______________________________________________
            > Diy_efi mailing list
            > Diy_efi at diy-efi.org
            > http://lists.diy-efi.org/mailman/listinfo/diy_efi
            >
            _______________________________________________
            Diy_efi mailing list
            Diy_efi at diy-efi.org
            http://lists.diy-efi.org/mailman/listinfo/diy_efi

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/diy_efi

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/diy_efi

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/diy_efi

    _______________________________________________
    Diy_efi mailing list
    Diy_efi at diy-efi.org
    http://lists.diy-efi.org/mailman/listinfo/diy_efi

------------------------------------------------------------------------------

  _______________________________________________
  Diy_efi mailing list
  Diy_efi at diy-efi.org
  http://lists.diy-efi.org/mailman/listinfo/diy_efi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.diy-efi.org/pipermail/diy_efi/attachments/20121101/c1ebdcef/attachment-0001.html 