JimStim Wheel Pattern Issues/Inaccuracies

Discuss MegaSquirt, VEMS and other non-free hardware and software here.
User avatar
jbelanger
LQFP144 - On Top Of The Game
Posts: 387
Joined: Sat Feb 23, 2008 8:58 pm
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by jbelanger »

Well, I just put the scope on the JimStim and I don't see it anywhere on the full RPM range. So either you have a defective JimStim or your firmware is not logging what is actually happenning or there is a comm issue.

So unless you can actually scope this and tell me how you managed to get this, I'll have to assume it's an error on your side. And you might want to check your logging because if there is a problem there it might come back and bite you at some point.

Jean
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by Fred »

The logging is solid, mark my words :-) I will try to verify this behaviour for you and provide specifics on it. Which JS firmware is on yours? Mine has V2.0.3 on it, I assume that is accurate?
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
User avatar
jbelanger
LQFP144 - On Top Of The Game
Posts: 387
Joined: Sat Feb 23, 2008 8:58 pm
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by jbelanger »

Yes, V2.0.3 is correct and is what I have.
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by Fred »

Fred wrote:The logging is solid, mark my words :-) I will try to verify this behaviour for you and provide specifics on it. Which JS firmware is on yours? Mine has V2.0.3 on it, I assume that is accurate?
I owe a slight apology for this statement. I couldn't replicate the screen shot posted above with later versions of OLV and the SAME log file... so I think there was a bug in that. Furthermore, unless the listener decoder is being used, the mathematics can delay the packets and introduce something like 1/2/3 ms errors into the graph. At low rpm this doesn't matter, however at high rpm it definitely does. I was partly right, but partly wrong. I'm sorry! :-)

As for the pattern, everything I said about that remains true. It's useless for testing the 4and1 CAS decoder in FreeEMS, which is a pity.

Fred.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by Fred »

I'm stuck in this horrible city called Barcelona with no car, so I needed the JimStim to work for me. Thus I fixed the 4/1 CAS mode for it and have verified it with FreeEMS LA mode as being close enough for government work. Below is a screen shot with latest OLV of both log taken from my truck 6+ months ago and log taken from JimStim with my file in it today. RPM is slightly different, so the scale is a little off, but the pattern is about right.

Image

The file is here if anyone has a Mazda or Mitsi engine AND a JimStim AND wants to bench test their FreeEMS or verify that the MS2 4/1 code does actually work (as it was never tested with the real pattern, and my friend Dan had massive troubles with it until he switched to the DSM disk and decoder in MS2E...), you can get the file here:

http://stuff.fredcooke.com/wheels_fixed.jsw

May the testing and development commence! :-)

Fred.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by Fred »

DSM pattern is within a few degrees of where I think it should be and edge alignments are correct, so I can use it. Data here:

viewtopic.php?p=17931#p17931
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by Fred »

Fred-verified pattern library online now: viewtopic.php?f=6&t=1344
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: JimStim Wheel Pattern Issues/Inaccuracies

Post by Fred »

I got screwed by the mighty JimStim again today :-(

I loaded 20 36-1 and 20 60-2 into one file alternating and loaded it. First half a dozen had 32-0.5 pattern, then the balance seemed to be a mix of the two loaded. I was stuck on the wrong one for ages. Turns out that my code is working OK and I was barking up wrong trees for hours... I may have gotten slightly angry. Screenies showing wrongness:

MissingTeethNormalTooth.png:
Image

MissingTeethMissingTooth.png:
Image

MissingTeethToothCount.png:
Image

I'll be more careful in future...

Fred.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
Post Reply