Sensor Flickers in MegaTune
 

Finally got everything built, wired, and installed in the car this week, but a problem that I thought might be stim only has decided to be a problem in the car too:

When I'm in mega tune the all of the read outs intermittently blip and spaz out for a second. Sometimes it happens for a few seconds, sometimes once, sometimes not at all. I had thought it might be an assembly issue (and it still could be) but the weird thing is that MegaTunix is steady as hell and works great. While I love MegaTunix just fine - being new to this game I'd like to stick to the well beaten and well documented path.

Anybody have any ideas why it's doing this?

Post a datalog, a short one, that will tell us a lot. It could just be a communications error. Are you connected directly with the DB9 cable or are you using an adapter?

It's an adapter, the one that DIYAutotune sells.

Here's a datalog from last night. Includes some idling, a drive around the block (to see if it only happened at idle), and some more idling. Also I think my O2 isn't connected right or is not calibrated correctly. But that's another issue entirely.

http://empirverts.com/shackage/datalog.zip

I have had similar resets. They are communications based, so says your datalog. Let me find a link to refer you to on how you might be able to fix it.
Does the car misfire or make anychanges when you notice a flicker in MT?
Edit:
Here is a post by Matt Cramer at DIYautotune telling me how to solve my problem.
https://www.miataturbo.net/showpost....2&postcount=22

You should also email them a link to that datalog and tell them your problem. They might have more insight, as i'm no MS guru.

I have once, but I'll certainly do that again. Have a less clumsy iron now.

That actually makes a ton of sense and makes me wonder why I didn't put 2 and 2 together. The flickers happen, but nothing stumbles. Which would certainly suggest communication issue.

I'm just weirded out that it only happens on the windows side of things. ?! That's the main reason I didn't jump to communication issues I suppose, I figured if it was hardware it'd be consistent across platforms. Either way I'm going to go back over the DB37 and look at that thread you posted and see where I can get to.

Well, I've re-soldered the connectors on both ends, re-soldered any joints that looked poor, and added those two lines to my ini and still no dice. Resets and flickers.

Starting to think I have the same issues you're having cjernigan. Wish I knew why megatunix doesn't show these. Less sensitive maybe?

Just an update: Picked up a serial cable and dug my old desktop out - everything is rock solid now. Not a single reset in hours. Nice. Now only if I had something more, uh, portable.

it may just be something a bit 'different' about your USB port-- but let's not go there yet. And yes, megatunix has been found to be a bit less picky about comm issues.

What driver are you using with the USB-2920? The one downloaded via Windows update (internet) should work just fine, but there is a newer driver you could try. I've been running it for a while now, for no particular reason other than it was available-- http://www.ftdichip.com/Drivers/CDM/CDM%202.02.04.exe

It runs silently, then reboot and if you want you can check the driver version in Device Manager....

There are a few settings changes you can make too that often help-- a quick search for 'USB' in the MegaManual brought this up: http://www.megasquirt.info/connect.htm

It has all the info on these changes....

Hope this helps out man!

@FoundSoul - Thanks for the help and suggestions! I was using a driver from their site, but just in case I got it wrong I grabbed the one in your link. Same stuff.

I'm starting to think it's the computer (which btw is a MacBook Pro running XP in BootCamp, just in case you've heard of problems). I hooked the USB converter up to my desktop and it was solid, same with my Dell laptop. So at least I have those options (however the Dell is my wife's primary computer so disappearing for tuning drives is not advised =D).

So that's where it's at now, Serial port works, and USB works on everything but the Mac running Windows. =/

You mentioned that it could be something 'different' about my USB port, anything in particular?

Thanks again for all your help!

BTW - I also have worked with those setting in the Megamanual. Improved it a bit but never got it to go away. Increasing the polling interval helped too but still never quite resolved it. =(

By 'different' I basically meant something problematic or nonstandard about the USB port. What you just stated may be a clue actually--

MegaTunix runs directly on the Mac OS correct? Not inside of BootCamp? I'd think so as I know it can with MacOS being a **nix derivative. If so, then it has direct, hardware level access to the ports.

MegaTune is running inside of BootCamp, to trick it into thinking it's running on Windows. My guess (based on past experience with this type of app, not this one specifically) is that BootCamp presents the hardware to windows devices but doesn't give them direct hardware access-- and regardless it's definitely a part of the process now. My bet is it's getting in the way somehow. Are you running the latest version of Bootcamp? I wonder if it's tweekable concerning USB/Serial communications?

You're correct about Megatunix, it runs in X11 wonderful on Mac. If I knew more of what I was doing at this point I'd probably use it. I rather like a lot about it. But Megatune with all of its support and supporting apps is hard to say no to. =D

As for Bootcamp, I think it's just Apple's term for "Running windows on another partition". So I think it has access to everything directly (unlike running it in Parallels or VMWare where there's that virtualization layer) - but I'm wondering if even direct access isn't doing it well just because sometime Apple like to be fancy, aka non-standard/weird and Windows or the MegaSquirt is choking on it somehow.

Then again there might be the possibility that with how compact this laptop is that it's just noisy as hell. =P

I'll search around and see if anyone else has had similar problem with Macbooks and XP.

Thanks again for your help!

I've been running Megatune in windows under parallels and it was working fine, the only problem was i would get a couple resets now and again due to comm errors with the FTDI USB chip i had install in the MS. I removed it and hope that solves my problem, plan to use an external adapter but I'm gone for the weekend and won't know more till next week.