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-   -   Hi-Res code = ohmymotherfuckinggodamazing (https://www.miataturbo.net/megasquirt-18/hi-res-code-%3D-ohmymotherfuckinggodamazing-22350/)

Joe Perez 06-15-2008 07:43 PM


Originally Posted by elesjuan (Post 271672)
What are the downsides to Hi-Res on a 2.2 board?

As compared to Hi-Res on a 3.0 board? No dedicated ground plane, thinner traces, no proto area, no overcurrent protection...

Oh, you mean disadvantages to HR as compared to LR assuming both are on a 2.2 board. :D None. The only functional difference between HR and regular SnSExtra is the injector PW resolution and lack of Lo-z drive capability.

elesjuan 06-16-2008 01:27 AM


Originally Posted by Joe Perez (Post 271677)
As compared to Hi-Res on a 3.0 board? No dedicated ground plane, thinner traces, no proto area, no overcurrent protection...

Oh, you mean disadvantages to HR as compared to LR assuming both are on a 2.2 board. :D None. The only functional difference between HR and regular SnSExtra is the injector PW resolution and lack of Lo-z drive capability.

:hustler::hustler::hustler::jerkit::jerkit::jerkit :


So even with a flyback board with HR you lose the ability to use low-z injectors? Good deal, I'll look into giving that a shot. :giggle:;)

Joe Perez 06-16-2008 02:40 AM


Originally Posted by elesjuan (Post 271827)
So even with a flyback board with HR you lose the ability to use low-z injectors? Good deal, I'll look into giving that a shot. :giggle:;)

Correct. The reason for the discrepancy has to do with the limited hardware resources of the CPU. Remember that when you get right down to it, pretty much everything in the MS is time-based. Fuel, ignition, it all happens by counting the time elapsed between interrupts, and turning ports on and off for specified lengths of time.

What the HR code does is to increase the resolution of the time calculation on the injector drive. It does this by repurposing one of the CPUs high-precision hardware timers to do the fuel calculation. In the base code, this timer was used to do the PWM calculation for the injector current-limiting, and the fuel calculation was done with a lower-precision general purpose timer.


The Flyback board is nothing more than a couple of transistors which, in the 3.0 schematic, are already on the main board. The overall design of the circuit is identical between the two, only the location of the parts changes. Be it a 3.0 or a 2.2 with Flyback, the same CPU resources are used to control the injector drivers. If those resources are unavailable, the drivers cannot function in PWM mode. Also, understand that the "Flyback circuit" is purely a damper circuit that is needed to protect the main drivers when they are operated in PWM mode. An unmodified 2.2 board could be run in PWM mode with lo-z injectors, but the drivers would probably be damaged.


However
, there is a board which replaces the injector drivers altogether and does the Peak & Hold current limiting in hardware, without intervention from the CPU. It will thus work with HR code. It's made by the same folks that brought us the JimStim: http://www.jbperf.com/p&h_board/index.html

They're using an LM1949 IC, which is a special purpose IC designed specifically for doing low-impedance injector control. It's a beautiful design, you just feed it the regular injector signal, and it takes care of doing the current ramp-down after the initial opening period.

I think Abe is planning to try it as he's been having electrical issues with his on-board injector drivers.

rb26dett 06-16-2008 06:18 AM

Actually (from the horses mouth) it's "about 0.02 - 0.03" ms (20 - 30us) fuel resolution. MS2 does it to 0.6666us in hardware and if you look at the comparison chart between different ms variants here :

http://www.msextra.com/ms2extra/MS2-...l.htm#features

It still says 100us* where * = "hires can do better than this, but we aren't specifying how much"

I just thought it was unfair on MS2 to claim ms1e hires can match it for fuel accuracy. It simply can't. Light years ahead of ms1 ah la plain though, so your excitement is justified :-)

It's worth noting that the software accuracy behind the hardware output makes a big difference too. Case in point, ms2 b&g vs. ms2e, ms2e has extensively rewritten math to make use of the hardware accuracy that ms2 b&g just doesn't have.

Fred.

Joe Perez 06-16-2008 12:11 PM


Originally Posted by rb26dett (Post 271849)
I just thought it was unfair on MS2 to claim ms1e hires can match it for fuel accuracy.

Uh, Fred, I don't think anybody here was claiming that MS1-HR was equal or superior to MS2. I think we're all in agreement that MS2 is more accurate than any MS1 with regard to fuel resolution.

Exact specs are hard to come by, but some numbers seem to show up more often than others.

To quote Phil, James & Co. from the MS1E-HR manual:

The MS1 uP's code, be it MS-Extra or standard B+G code, is capable of controlling the injector's pulse width down to 0.1mS (1000th of a Second). (...) The HR code has a resolution of around 0.035mS
and to quote the B&G documentation for MS2,

Fuel control to 1 µsec (100 times more resolution than MegaSquirt-I)
So, regular MS1 or MS1Extra has a resolution of about 100µs, MS1Extra-HR has a resolution of about 35µs (three times more accurate) and MS2 has a resolution of about 1µs, blowing them all away.

I'm sure there is point of diminishing returns in this, though I don't know where it is exactly. I doubt that increasing the resolution to, say .01µs would buy you anything palpable over the MS2's stock 1µs resolution.

The point is simply that going from MS1-Extra to MS1-HR, and gaining three times the fuel resolution, is a significant change.

Toddcod 06-16-2008 12:25 PM


Originally Posted by rb26dett (Post 271849)
Actually (from the horses mouth) it's "about 0.02 - 0.03" ms (20 - 30us) fuel resolution. MS2 does it to 0.6666us in hardware and if you look at the comparison chart between different ms variants here :

http://www.msextra.com/ms2extra/MS2-...l.htm#features

It still says 100us* where * = "hires can do better than this, but we aren't specifying how much"

I just thought it was unfair on MS2 to claim ms1e hires can match it for fuel accuracy. It simply can't. Light years ahead of ms1 ah la plain though, so your excitement is justified :-)

It's worth noting that the software accuracy behind the hardware output makes a big difference too. Case in point, ms2 b&g vs. ms2e, ms2e has extensively rewritten math to make use of the hardware accuracy that ms2 b&g just doesn't have.

Fred.

YEaaaaaa.......
So I have MSPNP9093. i just installed it recently. I am installing my 550cc injectors. So I just need to download the Hi res and burn the firmware. Then everything works the same. Just more precise.

I was told my injectors were RC550CC from flying Miata. But how do i make sure they are rc550 and High ped. A red neck did own it.

Joe Perez 06-16-2008 12:35 PM


Originally Posted by Toddcod (Post 271959)
. I am installing my 550cc injectors. So I just need to download the Hi res and burn the firmware. Then everything works the same. Just more precise.

Assuming the 550s are hi-z, then yes. You'll probably need to tweak your VE table a bit.


Anyone have the exact link to the download. I don't wanna screw it up. This isn't something I wanna search or try to find the right one. Trust me. I would appreciate the help.
The latest HR code can always be found in the "Latest HiRes" thread here: http://www.msextra.com/viewtopic.php?f=90&t=25336

rb26dett 06-16-2008 12:36 PM


Originally Posted by Joe Perez (Post 271952)
Uh, Fred, I don't think anybody here was claiming that MS1-HR was equal or superior to MS2.

Not quite, but it would have been easy to read this :


Originally Posted by Braineack (Post 271643)
hi-res removes a few things form teh sandard extra code to be able to control injectors to the .000ms. this gives you tons of extra control.

or this :


Originally Posted by Braineack (Post 271643)
for example, i have yet to install it. i idle at 1.7. sometimes it fights between 1.7 and 1.8, this causes a slightly lumpy idle. When I give it the ability to idle at 1.758, it should be much smoooooother.

And infer a granularity of 1us exactly the same as (not better than or worse than) ms2.

That is all I was getting at.


To quote Phil, James & Co. from the MS1E-HR manual:

The MS1 uP's code, be it MS-Extra or standard B+G code, is capable of controlling the injector's pulse width down to 0.1mS (1000th of a Second). (...) The HR code has a resolution of around 0.035mS


So, regular MS1 or MS1Extra has a resolution of about 100µs, MS1Extra-HR has a resolution of about 35µs (three times more accurate)

Actually (from the horses mouth) it's "about 0.02 - 0.03" ms (20 - 30us) fuel resolution.
I was quoting an MS1Extra HiRes Author who I asked directly about the accuracy. Hence my comment "straight from the horses mouth" which is a little bit different to "straight from the horses documentation" although either of them could be as out of date/inaccurate as the other I guess :-)


The point is simply that going from MS1-Extra to MS1-HR, and gaining three times the fuel resolution, is a significant change.
Agreed, or perhaps as much as 5x increase in precision.

Additionally and somewhat off topic : ms2 res = 0.666us, not 1us :-)

When someone asks me about them I say this :

MS1base <= MS1Extra < MS1base HiRes <= MS1Extra HiRes << MS2 < MS2Extra

Which I think is a fair summary most of the time.

Fred.

Saml01 06-16-2008 12:59 PM

Damnit, I really have to go do this. It takes like 5 forking minutes, and im still putting it off. I guess I just dont want to remove the MS from the car if I need the cap mod.

Are you guys just reusing your low-res msq files, or re entering tables by hand into the hi res version?

crashnscar 06-16-2008 01:14 PM


Originally Posted by Saml01 (Post 271985)
Damnit, I really have to go do this. It takes like 5 forking minutes, and im still putting it off. I guess I just dont want to remove the MS from the car if I need the cap mod.

Are you guys just reusing your low-res msq files, or re entering tables by hand into the hi res version?

Just load your low-res msq and tweak.

mikeflys1 06-16-2008 01:15 PM

Reused mine...i think they only re-entered by hand because of a bug in the previous version.

rb26dett 06-16-2008 01:34 PM


Originally Posted by mikeflys1 (Post 272000)
Reused mine...i think they only re-entered by hand because of a bug in the previous version.

No, it's because of namespace/meaning differences in the contents of the tune. The way various vars are used can change between two versions and cause chaos if it doesn't match up. Usually it matches up though, so if there are no warnings or few warnings, you are probably OK. In the case of warnings, check the stuff they refer to.

ini files on the other hand, NEVER try to use those! MS has direct memory addressing through serial and a wrong ini (as it says when you try) will/can ruin everything :-)

Fred.

Saml01 06-16-2008 03:04 PM

Guess ill throw it on either today or tomorrow and see what happens.

I really hope I dont have to pull the MS for the cap mod, I hate taking it apart. Luckily I retained all my unused MS parts, and found a .22uf cap I could use just in case.

pace 06-17-2008 02:52 PM

I have been experiencing a driveability issue whereby the car would jerk and stutter if I was coasting downhill with the throttle just cracked open a hair. My assumption was that it was due to the overrun fuel cut option which I had enabled. I had tried tweaking the fuel cut parameters with no success.

After loading the high-res code and re-tuning the VE map for it, the issue appears to be gone !

Additionally, I now have a stable idle at 13.5:1 whereas it would oscillate wildly with the 029y4 code if I tried to lean the idle above 11:1.

I am impressed with what the high-res code has done for my setup.

levnubhin 06-19-2008 12:30 PM

1 Attachment(s)

Originally Posted by kotomile (Post 271115)
If your injector pulsewidth gauge shows "1.7" instead of "1.745", you aren't running HiRes.

also: If you haven't installed HiRes, you're not running HiRes.


My pulse gauge reads neither. Any ideas?

Attachment 212645
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kotomile 06-19-2008 12:39 PM

you're running 029v levnub.

Joe Perez 06-19-2008 12:55 PM


Originally Posted by levnubhin (Post 273449)
My pulse gauge reads neither. Any ideas?

"1.7" instead of "1.745" was just an example, to illustrate the use of one decimal place vs. three. "2.1" is a number with one decimal place of precision. Also, as kotomile pointed out, it says right up at the top of your screenshot (on the titlebar) that you are running 029v, which is not a HiRes build.

kotomile 06-19-2008 12:58 PM

I think he was being facetious FWIW.

Saml01 06-19-2008 01:39 PM

I installed it the other night, and just at IDLE I noticed that it was already superior to the low res firmware. Cant wait to drive it today but I imagine it being pretty much like the thread title and then some.

levnubhin 06-19-2008 01:44 PM

Anyone have any intrest in spending a few mins on the phone with me and walk me thru the install? Id appreciate it big time and would be sure to return the favor somehow. Im just affraid that I might blow something up.
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