MX-3.com

I'm reading and other manufacturers with OBD1 data ports are able to make their ECU's talk. Someone much smarter than me should do this for the MX-3.

For OBDI Mx-3's...They don't. Look at how long it took for people to crack Honda's code. For the limited functions and really no options for tuning, it's not worth the time or effort. All OBDII Mx-3's get is the ability for monitoring the systems. With the existance of megaquirt, you can do much more for less.

Yes that's what I figured. Hence my inquiry.

stroker on probetalk runs an emulator off his own custom EEprom chip, and is able to get some data while hes driving, and also modify values on the fly.

Custommx3 wrote:I use datalogging through OBDII over USB, as well as multimedia, gps, dvd, games, ect with my single core, works just fine. I started building it for my platform 6 years ago with an m9000 board, tweaking, rebuilding, trying everyway I could to squeeze the most out of my board. Upgrading to the m10000 was a jump with the nehemiah core. I'd love to get a dual core for myself, but this one works perfectly. EWF FTW

Ok well your code is probably all in C++. :p I wrote my system in Perl, originally as a prototype that spiraled out of control into a twisted complex application. Now it's >10,000 lines so I don't want to rewrite in C++ until I have a big chunk of time free. My data logging routines take about 30% of one core while drawing a fullscreen graph at 30fps, because it logs all system variables (instruments, timing information, accelerometers/gyros, etc) 50 times a second in dyno mode.

If I have my GPS running on XP under VirtualBox, that's another 25% CPU.

My software crossover takes about 40% of one core per 2-channel audio stream, because it resamples prior to applying the filters. 8 channels, 1 or 2 filters each (high/low pass, or both for band-pass), plus 16 equalization bands (notch filters). Plus software volume per-channel. If I have two streams playing (ie. audio, plus GPS speaking), and data logging, my CPU hits ~75% averaged across both cores.

As to why I went with Linux instead of Windows... honestly, it's just a personal preference and a bit of ignorance on my part. I know practically nothing about Windows... I use it to play games. I know it would have been a good choice, but I've been running Linux for the last 15 years (literally). So I know how to customize everything, write drivers (ie. for the spacenav), optimize boot time, etc.

Also, not bashing, but whats the point of HD content on a screen that will not even display HD resolutions? Its a bit of overkill isnt it?

Ah, of course you're right. I dunno why I threw that in there. I was grasping at straws, but um.. ok video games!

I want the expandability to be able to test new code for things like optical road tracking, radar autothrottle, traffic avoidance, etc.

As far as the screen goes, go with a transflective screen. I have 18% all the way around and 5% on the font, and the my screen still has problems with direct sunlight. The MX-3 may be a little better if you decide to mount it where the OP has his, which is where my screen was in my mx-3.

Ya that makes all the difference. Mounted where I've got mine, honestly that $200 screen works beautifully. I've never had to squint even in bright sunlight.

wytbishop wrote:What do people do for OBD1?

OBD-I .. OBD-II... both suck. Ok, OBD-II sucks less since you can get data, but our ECUs use a very old protocol that runs at (iirc) 9000baud. So when you query a data parameter (PID) your response comes back in around 100ms. I can't actually manage more than about 4hz sustained. So if you're reading 10 parameters, you're looking at 2.5s between refreshes.

It's almost useless for any kind of tuning purposes.

Best bet is to grab some PLX gear, and use their serial->usb interface that runs at 10hz. That'll get you data like temperatures, boost, oil/fuel pressure, tach (I think), EGT, etc. For speed (and possibly tach) you're kinda hosed. If you need them in realtime your best bet is something like a Phidgets USB board, and voltage sensor... but you would have to write (or have someone write) a driver/API to actually make sense of, and log the data.

I spent a lot of hours writing integration code to guess the car's speed, gear and RPM based on the accelerometer's data, calibrated to the OBD-II output (whenever it happens to mosey on into the buffer).

Alternatively to all this, you could get a megasquirt... As far as I know they have a full data interface. I'll be experimenting with this later this year.

Yeah the minimal reading and research I did led me to that conclusion in a few minutes. On the upside, MS is the gateway to turbo which is also in the future of my dreams plus it will give me great tuning capability until that time. MSnS is a win win. I think that's my next step after the body. I've got my ZE running pretty well now. Once the bushings are done the chassis and drivetrain will be very close to perfect. Then the body has to be done, then I will start thinking about toys.

Could you build me something that would plug directly into MS and do what I want it to do? I'm thinking of a trade. I am going to be working on some seriously killer suspension mods over the next couple of years.

wytbishop wrote:Yeah the minimal reading and research I did led me to that conclusion in a few minutes. On the upside, MS is the gateway to turbo which is also in the future of my dreams plus it will give me great tuning capability until that time. MSnS is a win win. I think that's my next step after the body. I've got my ZE running pretty well now. Once the bushings are done the chassis and drivetrain will be very close to perfect. Then the body has to be done, then I will start thinking about toys.

We're at exactly the same point. ZE running well, suspension solid, about to go MS & turbo, and focus on body work. Except you're building suspension components and I'm building the toys.

Could you build me something that would plug directly into MS and do what I want it to do? I'm thinking of a trade. I am going to be working on some seriously killer suspension mods over the next couple of years.

Certainly. I'll keep you in the loop as I figure it all out. I almost bought an MS2v3 from a reputable builder on ebay last night... one of these days I'll click one button too many and whoops! I've got an MS!

If I manage to come up with something reliable I'll send you one.

I'm a little worried that once I start down that path I'll be car-broke for the next year or so. I don't like chipping away at projects, but obsessing until they're done. I just dropped $2k on gauges, a nice slide hammer kit, new axles, wheel bearings, and a 10-ton arbor press... some other stuff. sigh. I can only imagine what a turbo MS ZE setup will end up costing.

If someone were to build the ms and harnesses, they'd make a killing! Tailor made for the user.

nightfire wrote:

wytbishop wrote: I can only imagine what a turbo MS ZE setup will end up costing.

lol, i know all too well and its still not in the car