Search found 136 matches

by mk e
Sat May 30, 2020 11:22 am
Forum: Misc
Topic: How does ABS work?
Replies: 7
Views: 850

Re: How does ABS work?

As for why you appear to have 3 valves per brake pad. I'm not sure. I know there is a cross over valve, such that if the front left brake line breaks, this valve will engage and block flow to the front left, as well as the rear right. Basically it's usually a metal ball in the brake lines. If you h...
by mk e
Tue May 12, 2020 4:24 pm
Forum: Hardware
Topic: Injector setup (find offset table)
Replies: 8
Views: 225

Re: Injector setup (find dead time)

Deadtime or offset is a function of voltage and fuel pressure so you will almost certainly NOT get a good correlation to a point value if you alter these parameters as you're describing. You can find tables in a few different control scheme formats to see what it should look like at places like this...
by mk e
Thu May 07, 2020 1:33 pm
Forum: Software
Topic: E85 / Flex fuel logic
Replies: 25
Views: 4982

Re: E85 / Flex fuel logic

winner winner chicken dinner. :) I think he no play PUBG ... You caught me, I don't play any games...they all bore the shit out of me, I just can't for the life of me understand the point of them. I make things that are real when I have time...today I'm working on retaining wall then a patio, killi...
by mk e
Sun May 03, 2020 1:45 am
Forum: Software
Topic: E85 / Flex fuel logic
Replies: 25
Views: 4982

Re: E85 / Flex fuel logic

winner winner chicken dinner. :)
by mk e
Wed Apr 29, 2020 10:39 pm
Forum: Software
Topic: E85 / Flex fuel logic
Replies: 25
Views: 4982

Re: E85 / Flex fuel logic

It should as simple as: Read fuel sensor Interpolated between E10 and E85 tuning There shouldn't be any more to it that that I don't think? It my setup I use the stoich value and mass flow so I won't use 2 tuning tables, I'd use use the stoich values to calculate required fuel volume and get the inj...
by mk e
Sun Apr 05, 2020 1:40 am
Forum: Software
Topic: Fast start features
Replies: 15
Views: 1766

Re: Fast start features

JPh wrote:
Wed Apr 01, 2020 9:00 pm
Perhaps I will enhance the starting ability by adding supercapacitor.
Or a proper battery ;)

Seriously, its easy to get caught up in trying to make something perfect and end up with something unusable or fragile instead.....I've fallen for that many times over the year :oops:
by mk e
Tue Mar 31, 2020 2:58 pm
Forum: Software
Topic: Dwell problem during starting ? No - caution at flywheel setup
Replies: 37
Views: 1860

Re: Dwell problem during starting ? No - caution at flywheel setup

That trigger wheel has both a missing and added tooth.....the scope trace looks correct I think for the wheel design I think, does the software support this style trigger wheel? It does look like the sensor should be rotated 90deg as mentioned though.
by mk e
Tue Mar 31, 2020 2:48 pm
Forum: Software
Topic: Fast start features
Replies: 15
Views: 1766

Re: Fast start features

I have always felt that fast start is best left to OEMs trying to satisfy irrational customer perceptions and racers want start DELAY so there is time to get oil, often thicker and much slower moving than the 0W20 many OEMS now use , flowing BEFORE the engine comes to life. Years ago before EFI I ho...
by mk e
Mon Mar 30, 2020 2:27 pm
Forum: Misc
Topic: Anyone with personal Anodizing experience?
Replies: 1
Views: 900

Re: Anyone with personal Anodizing experience?

I always sent out. The main issue is always what the heck to do with the chemicals???? which for me has always made it not worth messing with.
by mk e
Fri Mar 13, 2020 3:39 pm
Forum: Misc
Topic: Powder Coating
Replies: 3
Views: 1651

Re: Powder Coating

Just be sure to NOT use the oven you cook food in....the stuff is somewhat is poisonous and off-gasses so it contaminates the oven.
by mk e
Wed Feb 12, 2020 1:09 pm
Forum: Misc
Topic: FPGA in ECU
Replies: 43
Views: 17489

Re: FPGA in ECU

I do think its the best approach to create a high performance, lowish cost open source ECU but sadly the only thing I can contribute is best wishes as I have no knowledge or skill that would actually help at this stage :( The problem seems to always be convincing people that they need more accuracy ...
by mk e
Wed Jan 22, 2020 6:47 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

I may have more going in what I call fuel calculations and the you do. This is the fuel script that assembles the subroutines I call (with there inputs listed) I think this is all fuel other than the .\Cylinder_Trim.elcfg item and remember its a higher level language that best I can tell is just cal...
by mk e
Wed Jan 22, 2020 3:44 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

I guess I could add a timer to the thread itself which would clear up how long it waits in Que.....I'll have to thin(k) about that because as I said its library based so easy in C is not always easy. I looked at it a little and so far haven't come up with anything as I only have access at the upper...
by mk e
Wed Jan 22, 2020 2:53 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

I guess I could add a timer to the thread itself which would clear up how long it waits in Que.....I'll have to thin(k) about that because as I said its library based so easy in C is not always easy. I looked at it a little and so far haven't come up with anything as I only have access at the upper...
by mk e
Wed Jan 22, 2020 12:37 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

What ECU is that? Remember that we have many threads (on the order of 15) that are all completely independent. Most of them are rate limited, but a few (Tunerstudio, for example) are not. So if TS isn't connected it uses exactly zero cycles. A bunch of stuff that might be on the same thread for you...
by mk e
Tue Jan 21, 2020 2:05 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Here's the thread times on the real HW for comparison. Thread 2 is the main fuel/spark calcs and I lied, the units are seconds. It's a simple dt, so time since last run and the thread is on a 7ms sleep. so actual run time is about (forgot to check actual sleep times) 9.64msec-7msec = 2.64msec on the...
by mk e
Tue Jan 21, 2020 12:14 am
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Here are my thread times running in the simulator on a PC.....I have a timer on each thread just cause....I'll try to load it into the HW and show the difference and clearly I need to fix the min. Times are msec.
by mk e
Mon Jan 20, 2020 4:13 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

do they have fpu? :-) of course....along with all the other stuff MCU chips normally have...built in watchdog, AN signals read, converted, moved to memory with no CPU action needed, buckets of timers in a time processing unit...purpose built for MCU use hence my confusion. The freescale MPC5xxx chi...
by mk e
Mon Jan 20, 2020 1:07 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

It's not a tight loop. We do the math in ~150us, then wait until it's time to run again, to rate-limit to 200hz. That is very fast. Is that just the calcs or does it include updating the sensor values, comms, and everything else while its being interrupted with time critical stuff? That is much fas...
by mk e
Mon Jan 20, 2020 2:40 am
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Yes - we already have this, in the form of the performance tracing. The processor loading is not bad at all. Our 200hz callback to compute things like ignition timing, fuel quantity, etc usually takes only a few hundred microseconds, even when running an engine at speed like in these tests. I can g...
by mk e
Mon Jan 20, 2020 12:23 am
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

I don't mean that it's necessarily exactly normal, but it's normal-ish to within the ability of my logic analyzer to measure. Of course (barring the long linear part) it has a longer tail on the slow side than the fast side, but it is at least bell curve shaped. Here's a zoom in on region 1: That p...
by mk e
Sun Jan 19, 2020 10:31 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

First, excellent data, well done collecting it. Don't let this thought be lost when I start talking about what I think I see. Looking at the data...there is no normal region, here is cause 1 and cause 2. I did some work years ago with 1 sided distribution (weld strength limited by the a hard stop at...
by mk e
Sat Jan 18, 2020 11:53 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Yes - more data coming. The existing improvements I made last week seemed to actually make my engine noticeably smoother - turns out reducing ignition timing jitter by an order of magnitude works wonders. I've been looking in to where the long tail in the timing inaccuracy is coming from, and the d...
by mk e
Sat Jan 18, 2020 5:46 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

I swear we're all somehow saying the same things? but when I read this: It's possible to build a zero jitter, zero error system even when using interrupts, provided your hardware timers are arranged properly. I know we are. Because the current solution does not do this, the whole FPGA idea now is t...
by mk e
Fri Jan 17, 2020 12:44 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Forgot...first things first, figure out where the current system limits are. It certainly works under some or maybe most conditions so its absolutely worth figuring out where the limits are before making it more expensive and complicated. How many channels are on the logic analyzer? 4? I ask becaus...
by mk e
Fri Jan 17, 2020 2:49 am
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Forgot...first things first, figure out where the current system limits are. It certainly works under some or maybe most conditions so its absolutely worth figuring out where the limits are before making it more expensive and complicated.
by mk e
Fri Jan 17, 2020 12:14 am
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

It just seems like a bad idea to pass time critical info between crazy fast and not so fast systems.....way back I learned the expression "put the aces in their places" and it's usually the right answer.
by mk e
Thu Jan 16, 2020 11:25 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

mck1117 wrote:
Thu Jan 16, 2020 11:09 pm
It's significantly more area and power required for not really any real performance benefit.
The benefit is crank decoding and spark have virtually no lag and no meaningful distribution tail. Interrupts are the devil.
by mk e
Thu Jan 16, 2020 2:23 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

Dron_Gus wrote:
Thu Jan 16, 2020 2:13 pm
... But stm does not have such advanced timers. ....
[/quote]

hence the fpga thread
https://rusefi.com/forum/viewtopic.php?f=13&p=35305#p35305
by mk e
Thu Jan 16, 2020 1:42 pm
Forum: Software
Topic: [info] rusEfi Scheduler Performance & Accuracy
Replies: 55
Views: 15895

Re: [info] rusEfi Scheduler Performance & Accuracy

I don't think so. If you're an OEM then you have no choice but to comply with any and all applicable standards but as a hobby yo have a lot more flexibility....as long as you've made an honest effort to go through and look at what could go wrong and addressed any that are a safety related I'd say y...