megatune acting crazy

[nukkinfuttz]

When i startup megatune, and let it attach to megasquirt with the key on, but engine not running, it will talk just fine. If i then start the car, and there is a mometary power interuption to megasquirt, megatune will lock up. it will lock up so bad, i have to turn power off to the laptop to make it get off the screen.

If i start the car and get the engine running, then open and run megatune, it will communicate just fine. but at random intervals megatune will lock slam up, and again, i must turn power off to the laptop to get it to clear off the screen or allow me to open another copy of megatune.

any ideas how to cure this? its driving me crazy.

[jsmcortina]

This sounds like maybe the USB-serial driver crashed?

I've seen this with the FTDI driver on Linux and less so on Windows. If I get a power spike or something the USB disconnects and gets in a right mess.

James

[nukkinfuttz]

ok, im with you so far... what would be my next course of action then? Is there a way to troubleshoot this somehow?

[jsmcortina]

You could try upgrading the USB driver I guess?

I know in my Linux case it is a kernel bug, but I don't know enough about kernel coding to try to fix it myself.

It might also be related to ground loops and power supply issues. e.g. if you are using an invertor to power a laptop in the car you might get odd ground potential issues down the USB cable that aggravate the problem.

James

[LT401Vette]

My suggestion would be a different cable. After seeing so many people having trouble with various usb-serial cables and to try to make sure TunerStudio worked with as many cables as possible I bought a whole lot a of cables a couple years back. It seemed like just about every cable I tried worked fine, I didn't understand why there were so may troubles. But the trouble was I was testing them on the bench in my house.. I later found that some of these cables if you put them in a real car would do things very much like you describe. It would work for random amounts of time them loose connection or go wacky.
Apparently some cables just aren't shielded well enough to keep all the EM noise inside a running car from causing troubles.

Get a decent cable and I bet your problem will be solved. And decent doesn't mean expensive. The one I use most is a Belikin I got on eBay for $1, it works great.

[nukkinfuttz]

i found that my laptop had a virus, so i used my antivirus software to remove it, and now the Megatune and TS work fine with all the original hardware. go figure.... lol

[acalvo]

I had freezing/crashing issues with MegaTune too, to the point where I had to manually power off the machine (the hard way). I upgraded memory today to my computer (it had only 1GB of RAM, now its running 8GB of RAM, a bit overkill but it helps a lot), AND I also changed the cable today from USB-serialDB9 to a maleDB9-femaleDB9 cable. I changed both things at the same time, so I'm not sure which one for sure fixed the MegaTune (maybe both helped), but I'm pretty sure it's the cable. Before, MegaTune crashed at least once every hour, and after the change it hasn't crashed once yet, and I ran MegaTune the WHOLE day today.