Possible uses of our timer resources : ideas soon please!

[Fred]

I think seq on at least 8 would be a big plus. You could batch fire a second set of injectors and as long as you didn’t max out your seq controlled set, you can still have individual cyl fuel trim control.

I agree, but whether we have that code in the same release as the timer based stuff I'm not so sure about. Once you have code switching 8 channels with 2 timers, you can keep sequential for staged ones provided that the end time is the same (or start time) and use only 3 timers to do that control. 4 for water if it also has the same end point etc.

Not likely, 10 cyl maybe (ford/dodge v10s are somewhat common in some countries, but most people that need big power chose V8s).

Exactly, and although they might be semi common, they aren't heavily used by low budget DIY types looking for insane power are they. Like you say, V8 is the common choice for easy reliable silly power over there. At home it is boost and RPM on rb/2jz/3sg/sr20/etc that is the common choice for fast cars with fuel injection. (like your 8's are cheap, our jap market imports are dirt cheap too)

Traction control would be a nice feature especially for real race cars. Having an idle rpm/MPH table would be neat, that's one reason I let the stock ecu control my iac valve. With vehicle speed we could do transmission controls too, a typical auto trans controller sells for several hundred US dollars.

I'm adamant that we should build a fuel/ign controller with good accessory control. Trans seems to me to be a whole application of it's own. I'm wondering if you have seen lances/James trans controller stuff? A member on msextra called devojet is using a 90usd ms2 card and some perf board to control his toyota trans. the gpio board might cost around 150us when/if it comes out. our cpu card alone is 125us +p+p, might be cheaper easier more fun to do it that way rather than try to hack it into the middle of the ecu code. I'm keen for traction control, and wheel speed logging too, but I don't think we *need* timers to do it reasonably.

Im a big fan of doing more with less, but how much more would it cost for a fully qualified MCU and when you factor in how much you spend on the average project does it really cost that much more?

So am I, but the answer to your question is a surprisingly large amount, at least if you stay freescale it is. 500us or so for an mpc555 (designed to run an engine) on a proto card not suitable for use in a project like this. The beauty of the tech art card, and the reason I/we went with them is the packaging. BTW, there are three of us with the xdp512 adapt cards now :-) picking up momentum! The xep cards are cheap, but also not that useful for integrating without major mods. The adapt card can be a plug in solution with the possible exception of replacing some tantalum caps that are 16V with 35V ones.

It would seem to me that the seq/semi-sqe model can be extended (much of the code resued) in the future on hardware that is more capable. When that times comes it seems like all other methods may become "effort better spent elsewhere" just a thought.

YES!! and a good thought, I'm glad you feel the same way :-) BTW, if you bought both the 40us xep100 card (assuming the pin count is the same) and the adapt, you could graft the new chip on. Most of the key pins probably line up the same. Freescale are good like that.

I would be very happy with 18 outputs(8ign, 8 seq,1 batch fuel, 1 batch meth), but I dont have a problem with semi seq model at this time.

I intend that the output board will have 24 power devices built into it (provision for them anyway) another board can be sandwiched on for more. I think there is no reason that the BASE (have to keep reiterating that it is a BASE for others to work from and extend) couldn't be brought up to any arbitrary number of channels later. The compromise would be much less logging, and loss of accuracy from excess load.

I'm definitely not the most experienced hardware/software guy on this board but , I would rather see this project grow with the hardware rather than trying to do too much with too little.

I'm glad you feel like that. I think we need to hone in on the angle of attack and commit to it. I thought I had, but you lot seem to have some other ideas :-p (not pointing the finger at anyone in particular Jean ;-) )

We can't spend forever discussing how many channels for what under every random combination of engine/trigger/setup etc. We need to make some decisions and lay down some designs.

I propose that we stick with this for now :

6 timer injector channels running seq or semi seq
6 staged injectors with a PIT controlling start point, and ECT end point at the same time as main
12 ign channels controlled by two PIT timers

leave sequential V8,10,12 for later
leave full hard core siamese control for later
leave water injection for later (its a hack anyway, run good fuel or drop your compression to a reasonable level, too many people are too hung up on high compression at the same time as boost...)

Note, I'm not saying don't do them (do absolutely anything at some stage) I'm just saying don't do them now.

How does that sound to you two that care : Jean, Sean ?

Next...

[Fred]

I have one question I want to preface this all with: Is there anything inheriently wrong with doing *everything* as a bit bang?

YES! you lose accuracy that you could have been using to good effect.

I think (what I call batched and you call semi-sequential) is fine for secondary type injectors (water, high flow rate fuel) - sequential is really only a concern at low speed low power.

batch doesn't imply intelligently wired and timed. Semi seq does. Otherwise while I agree that its not overly important at higher revs/pulsewidths, it is still important despite how brain washed you (or i unfortunately) have become to the contrary on msefi.com. Also, its only a pin count thing if you use a single timer to start them, or two timers to control them outright.

Traction control that only noticed that the wheel spun 4 rotations when it was supposed to spin 2 isn't doing you much good. If you want to know where to put more timers, use 4 for bit-banged injection as Jean suggested, and put the rest watching generic wheels like that.

I'll say it again, there is no way in hell any SIGNIFICANT compromises will be made to fundamental fuel/ign control for an accessory function. Secondly, do the math for us Flacid, how far can a wheel turn in 3rd gear with 100mph redline in that gear and 0.128 ms between potential samplings? If you have issues with the tooth count between RTI executions being too low : 4/5/4/5 etc you can use the one sampling interrupt being measured two fold short period for delta speed, long period for speed etc.

Till next time,

Admin.

[jbelanger]

I would need to do the computation but I'm not convinced that you would not get to much jitter from that to not have quite a bit of noise if you wanted to extract HP measurements from the data. But if you say so, then it's fine.

I'm not sure if i detect tone in that last bit, but I wasn't trying to say its as good, just that it is good enough.

Sorry, I did not imply any tone.

Now I'm thinking that you were vague AND I misinterpretted it as one per cyl rather than staged, but anyway...

You need a 3d timing map to configure it regardless, you also want mid point injection, then you want separate timing on the staged channels compared to the main rather than using larger mains or one per cyl etc. None of these things are required at all for any normal engine. I understand the desire to do it, and I'd be keen to be involved with trying to make it happen, but the code comnplexity costs and config costs seem very high for the support of a rather small minority group if you include them for all users. It seems to me that a branch that for example only supported 36-1/+1 trigger type and special tables/special algorithms etc to support it properly without compromising it's operation to fit with the norm, or the norms comfort/performance to fit with it. Do you see where I'm coming from?

It seems analogous to special needs groups getting govt grants for their religions and cultural practices when normal people get no such grants (effective tax rebates) because they are normal. i.e. pretty unfair.

If you can show me a detailed design that works good saimese control (NOT average) in with GREAT normal sequential control in a clean config freeish way, I'm all for it. I just can't see how it can fit together when the requirements are SO different.

The thing is, there are other blocks of code that should get all of our work that all of us need :
basic structure/tables/settings/interfaces
serial comms
etc etc
Being aware of making it compatible with siamese while designing is a good thing (provided it does not force massive unnecessary compromise) but at the end of the day, it's not all that much of a big deal to retrofit an extra timing table or two, add a few extra calcs, and vars to read from and change the wheel code to suit.

That last statement seems to contradict what you were saying about things being so different above but it's true that the requirement are specific and that's why it hasn't been done well yet. And I agree that you should concentrate your efforts on what is more important for more people now.

Anyway, I think basic non staged 2 injector proper siamese injection is a reality without any funky compromises regardless. What are the upper echelons or power for a 1300cc A engine anyway? How large do you have to go injector wise to support it? I'm guessing less than 300hp, probably less than 260hp. if you can only use 50% of the injector and carry only 2 injectors, you need 1200cc injectors to do it singly. They might idle ok with proper timer control, but maybe not i guess. Then again, the price of extreme specific power is always compromise in idle etc unless you go to matching extreme lengths to counter it (staged etc). I'll probably put 750 - 1000 cc injectors on my fe3 when I get home to try to max out the holset. I expect that it might be slightly rich at idle with it like this. That is the compromise of massive power

If I'm being unreasonable, please tell me.

Next...

I don't have time to go in details now but I don't think it would be worth doing it this way with the Mini engine because idle would be even more compromised due to the configuration. But I'm not ready to do an installation at this time so this is not an issue.

Jean

[Fred]

Sorry, I did not imply any tone.

No need to apologise :-) Just clarifying the meaning of the statement. The way I read it seemed to make it more sarcastic than serious. Now I know what you meant :-)

I tend to think that if I take offense to something you say (especially if its purely techy) it's my problem unless I say something about it. Not that I took offense then, but... you see what I mean. So, don't be sorry excessively or I'll have to start calling you "English" :-p ;-)

That last statement seems to contradict what you were saying about things being so different above but it's true that the requirement are specific and that's why it hasn't been done well yet. And I agree that you should concentrate your efforts on what is more important for more people now.

What I meant was : Easy enough to add in, but not in a way without excess complication and overhead for everyone else.

I don't have time to go in details now but I don't think it would be worth doing it this way with the Mini engine because idle would be even more compromised due to the configuration. But I'm not ready to do an installation at this time so this is not an issue.

Well, if and when you do find time, you could put a post up not with a description of the breathing (that is well covered) but a concise set of control requirements instead. i.e. what exactly you need to be able to control in every aspect. That way it would be clear to someone like me without having to dig into breathing details etc.

Thanks,

Admin.

[SleepyKeys]

I'm adamant that we should build a fuel/ign controller with good accessory control. Trans seems to me to be a whole application of it's own. I'm wondering if you have seen lances/James trans controller stuff? A member on msextra called devojet is using a 90usd ms2 card and some perf board to control his toyota trans. the gpio board might cost around 150us when/if it comes out. our cpu card alone is 125us +p+p, might be cheaper easier more fun to do it that way rather than try to hack it into the middle of the ecu code. I'm keen for traction control, and wheel speed logging too, but I don't think we *need* timers to do it reasonably.

Agreed adding trans control isn't exactly trivial, that is if you want it to perform like it did from the factory. I have heard about ms trans control, but have not done much research on it.

So am I, but the answer to your question is a surprisingly large amount, at least if you stay freescale it is. 500us or so for an mpc555 (designed to run an engine) on a proto card not suitable for use in a project like this. The beauty of the tech art card, and the reason I/we went with them is the packaging. BTW, there are three of us with the xdp512 adapt cards now picking up momentum! The xep cards are cheap, but also not that useful for integrating without major mods. The adapt card can be a plug in solution with the possible exception of replacing some tantalum caps that are 16V with 35V ones.

Surprising indeed! I can see how easy the adapt card can be a direct "daughter card" plug-in, good for sight.

BTW, if you bought both the 40us xep100 card (assuming the pin count is the same) and the adapt, you could graft the new chip on. Most of the key pins probably line up the same.

A good budgeted approach and a good test of soldering skills as well. I think the xdp512 will keep us busy for quite some time.

I propose that we stick with this for now :

6 timer injector channels running seq or semi seq
6 staged injectors with a PIT controlling start point, and ECT end point at the same time as main
12 ign channels controlled by two PIT timers

It would seem that the hardware can do a superb job of this without compromising precision and make for a good base system. I'll solder to that

leave sequential V8,10,12 for later
leave full hard core siamese control for later
leave water injection for later (its a hack anyway, run good fuel or drop your compression to a reasonable level, too many people are too hung up on high compression at the same time as boost...)

semi seq in V8/10/12 mode would still be a big upgrade
After a good foundation is laid, then we can bring on the bells and whistles.

-sean

[Fred]

semi seq in V8/10/12 mode would still be a big upgrade
After a good foundation is laid, then we can bring on the bells and whistles.

Exactly! :-) (genuine large smile, you guys have had me a bit worried..)

BTW, nice effort on the quotes :-) :-p

[ababkin]

are we considering the "individual cyl fuel/advance trim" feature? (individually feedback-ed by EGT sensors for instance, or ion sensing) not for the near future of course, but just as a general design consideration (so we won't have to rewrite/resolder too much stuff later on)
I am just not sure if 2 PITs are going to be enough for ignition in light of this consideration. (fuel, i imagine is fine with the same amount of timers as there are cylinders)

[Fred]

Yeah, a pair of timers for each set of sequential bit banged outputs. The reason you need one per channel if you use them as hardware is because they literally switch the output without your intervention and are "attached" to that output.

Yes, individual tune exists in the very draft freeems.xml file in the releases. It needs some work, and as always, comments and suggestions are welcome on that.

Admin.

[ababkin]

Yeah, a pair of timers for each set of sequential bit banged outputs. The reason you need one per channel if you use them as hardware is because they literally switch the output without your intervention and are "attached" to that output.

Yes, individual tune exists in the very draft freeems.xml file in the releases. It needs some work, and as always, comments and suggestions are welcome on that.

Admin.

I was referring to your plan to use 2 PITs for ignition. It's ok to set dwell/adv for all coils, but not really if you individually trim dwell/adv for cylinders

[Fred]

how is it any different? when you look up which port to biff out, you look up when to do it too. unless the values are wildly off, it wont be significant, reality states that you only need like +/- 5-10 degrees for any given coil. that shouldn't create an overlap situation.