FreeEMS runs it's first engine! - For real this time! :-)

FreeEMS topics that aren't specific to hardware development or firmware development.
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Fred
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FreeEMS runs it's first engine! - For real this time! :-)

Post by Fred »

OK, so, the idling at 5am in -5C weather in Wisconsin would appear to be purely from the cold start 5th injector that the engine uses. The running at full load only drive up the hill was purely by luck as there was debug code that related map to pw and hence there was ONLY enough fuel at WOT (high map). However, drum roll please, du du du dah :

I just installed the latest S19 tht I emailed Cam and co a few days ago and it FCUKING WORKS :-)

I can rev it up and play with the throttle and it just runs sweet! :-) Of course the no sensible RPM bug is still present, but this pretty much confirms that the wave form is clean and that the RPM math is fuxored. Once I fix that and Aaron gets me something to tune it with, we'll be away laughing!

Then features can be added as I DRIVE ACROSS AMERICA ON FREEEMS and once that is over, we'll get serious about rearchitecting to use XGate and have a scheduler etc. I can see others using this in an experimental way in just a few months time.

History was just made (again, but for real) in a dodgy sketchy part of Baltimore Maryland USA.

Video tomorrow morning when I don't feel the need to lock the door while I fiddle...

Fred!!!
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by AbeFM »

Amazing! Can't wait for the video! How does the freeems know what to do if the RPM is wrong?I guess firing once per cyl is roughly correct no matter what, its just a flat VE map.
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by BenFenner »

We're all no doubt as excited as you. I read this yesterday and (almost) did a little dance for you. Then today I see that no one has responded, and figured I'd put in some appreciation here. I'm sure everyone else feels the same way. We're all excited to see the updates coming in daily of the progress. Sometimes maybe we just forget that you probably want our encouragement too. Frankly, this success is getting so routine around here it's almost not noteworthy when stuff goes well. Image

Keep up the good work!

Edit: Abe replied while I was typing! Image
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by sry_not4sale »

I'm too busy fighting wxPython to reply :P
Owner / Builder: 1983 Mazda Cosmo 12at (1200cc 2-rotor turbo) coupe [SPASTK]
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by Fred »

AbeFM wrote:How does the freeems know what to do if the RPM is wrong?I guess firing once per cyl is roughly correct no matter what, its just a flat VE map.
Exactly. I really need to get a scope on it and see what it's doing. Runs OK at various rpm and load points, but not everywhere, no surprise really. I'm just afraid I've been fooled again, but I don't think so this time.

Ben, get me your address before I bypass you :-p EDIT: Got it!

Aaron, good! :-p

Fred.
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by Fred »

Good news: The ECU really was and is running the engine OKish.
Bad news: The RPM bug isn't the only issue, we have noise. The reason it isn't staying running and isn't smooth is because the times recorded are spiking up and down. The injection occurs on these signals and thus isn't always occurring and thus fueling is inconsistent.

RPM bug is partly diagnosed and the build is unbroken again. Progress progress.

Next step is better grounding for the board and see if the missing etc goes away...

I also have heat soak/IAT lying issues which are so bad that I enabled one of FreeEMS' unique features and just overrode it to 20C temporarily - nice.

The PW's are pretty close in most cases. If you keep some inertia in the engine you can rev it up and down just fine. At fixed higher RPM in neutral it will stay running OK due to the fact that it can't slow down enough to stall during a glitch.

I wonder if I'm missing pulses or what... Hmmm.

Fred.
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by AbeFM »

Tooth Logger! With a cam pulse would be even better. I'd imagine you're inadvertantly filtering out your signal. don't you have a scope on your Eee-miracle?
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by jharvey »

I seem to recall the RPM sensor pickup was talked about but I can't seem to find that post now. Do I recall the wheel was replaced with an extended wheel, and it had two VR signals. One that ran the OEM ECU and an independent one that runs the FreeEMS signal? Really the big thing I'm curious about, is this hall or VR? If VR, are you using the LM1815?

I'm sure you know that the LM1815 default schematic isn't intended for missing tooth setups. You really need to empirically tune the discrete's to get it set correctly. The key issue is that the input isn't a differential input, which not only increases the common mode noise, it also makes it hard to reject the common mode noise. Kind of a double whammy that makes it sensitive to small hardware issues. To compensate for this noise, the default components have a fairly low gain, such that it won't trigger off small noise spikes. This low gain makes it sluggish when detecting the missing tooth, often causing it to miss the tooth, or inaccurately identify when the missing tooth has passed.

For VR setups, a better chip selection is the max9926 or max9927. I suspect the max9926 would be the better choice of a test mule. It includes some precision resistors, this make it a bit more of a general purpose chip, but easier to physically tune. It includes a differential input, with a high common mode noise rejection, this allows the sensing gain to be cranked up, and makes it more responsive / accurate too the missing tooth.
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by Fred »

AbeFM wrote:Tooth Logger! With a cam pulse would be even better. I'd imagine you're inadvertantly filtering out your signal. don't you have a scope on your Eee-miracle?
Damn it, Abe! You're right! I should definitely implement that ASAP, would be easy as hell to parse too. I can just pump out small log packets with only time stamps in them and we'll eventually see the issue in a reconstructed wave form. Good thinking mannering.

Jared, your question is already answered in the other thread.

Fred.
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Re: FreeEMS runs it's first engine! - For real this time! :-)

Post by jharvey »

Jared, your question is already answered in the other thread.
I must have been unclear here. I asked if you are using the LM1815, or other. I see the other thread notes "It has a dual ecu setup. 36-1", but it doesn't answer the above question.

At this point it doesn't matter, you know the issues with the LM1815, and if there is a solution, I'm sure you can figure it out.
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