Knock module for MS3 (beta test)

Testing and development of Megasquirt 3

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morrische
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Re: Knock module for MS3 (beta test)

Post by morrische »

I have seen in microcontroler.net a german guy wich is trying to build a Knock Sensor interface with the TPIC8101 and a atmel atmega8 (i think). He made this settings. I don't know if they are right but for him they work (or it seems like they work)

Frequency = 41 (6.94 kHz)
Gain = 63 (0.111)
Integrator = 24 (320us)

Somebody should correct me if i'm wrong (please)? (and i guess i'm wrong for sure like most of the time......... :D )
HeinrichG
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Re: Knock module for MS3 (beta test)

Post by HeinrichG »

jsmcortina wrote:I don't think there are enough pins on the MS3 to be able to do that. Certainly the current design doesn't permit that.

James
That's really pity :( :( :(

Regards,
Heinrich
jsmcortina
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Re: Knock module for MS3 (beta test)

Post by jsmcortina »

gross polluter wrote:Not having much luck with mine. Seems like there needs to me more attenuation before the signal gets to the ic,
Try adding resistors in series with the circuit (try externally to begin with) 47k or 100k.

James
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elaw
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Re: Knock module for MS3 (beta test)

Post by elaw »

gross polluter wrote:Not having much luck with mine. Seems like there needs to me more attenuation before the signal gets to the ic, at least with the factory 2JZ knock sensors. With the gain set to 1 the knock gauge always reads 101% with the gain at minimum the knock gauge bounces between 50% and 70% at idle and reads 101% off idle. Haven't had much time this week to tinker beyond installing the module and running it as-is.
Do you know if your engine has a resonant knock sensor? From what I've read, the resonant sensors have a much higher output (like 10x higher) than the non-resonant ones.

Just for comparison, my engine with two nonresonant sensors reads 8-20% at idle and cruise, getting up to 75+% at high RPM full-throttle (gain set to 1).
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
elaw
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Re: Knock module for MS3 (beta test)

Post by elaw »

James,

Just a few notes and questions...

First, in general the board seems to be working well on my 5-cylinder Audi engine with two sensors. Obviously some tuning is going to be required, but I datalogged my drive in to work this AM and behavior was about as I expected. I'll attach my msq and the log in case anyone's interested.

In the "knock sensor settings" window, can you confirm or deny my guess as to how "retard check time" and the coarse and fine steps work? My guess is the 1st time knock is detected, it retards by the coarse step. If knock is detected again within the "check time" it retards again by the coarse step, otherwise by the fine step. Am I right? :?

Also a minor issue: although I've got the advance check time and step size both set to 0.5, it seems to advance in 1-degree increments at 1-second intervals.

And lastly a request: any chance of being able to log knock value per-cylinder?

A note to anyone looking at the log: I was tuning the system as I went and ended up decreasing the sensitivity a lot. That's why more "knock" is detected at the beginning than the end. Also I removed a lot of chunks in the middle of the log to reduce its size.

Edit: one more thing I forgot to mention: if you look at the very beginning of the log, there's one point where the knock value spikes to 101.3%! I'm not sure it matters but I thought I'd point it out.
Last edited by elaw on Thu Feb 09, 2012 7:11 am, edited 1 time in total.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
Matt Cramer
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Re: Knock module for MS3 (beta test)

Post by Matt Cramer »

HeinrichG wrote:
jsmcortina wrote:I don't think there are enough pins on the MS3 to be able to do that. Certainly the current design doesn't permit that.

James
That's really pity :( :( :(

Regards,
Heinrich
It looks like you could do V12 / wasted spark with it with the right mods, though.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
jsmcortina
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Re: Knock module for MS3 (beta test)

Post by jsmcortina »

elaw wrote:First, in general the board seems to be working well on my 5-cylinder Audi engine with two sensors.
Good
In the "knock sensor settings" window, can you confirm or deny my guess as to how "retard check time" and the coarse and fine steps work? My guess is the 1st time knock is detected, it retards by the coarse step. If knock is detected again within the "check time" it retards again by the coarse step, otherwise by the fine step. Am I right? :?

Also a minor issue: although I've got the advance check time and step size both set to 0.5, it seems to advance in 1-degree increments at 1-second intervals
Most of that code is the standard MS2/BG knock code although I made one small change to add an new setting instead of sharing two settings. I need to write up a manual page. The info in the megamanual.com page isn't a totally accurate description of the MS2/BG code, but gives a starting point.
And lastly a request: any chance of being able to log knock value per-cylinder?
These are already in there as sensors9-16

James
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gross polluter
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Re: Knock module for MS3 (beta test)

Post by gross polluter »

elaw wrote:Do you know if your engine has a resonant knock sensor? From what I've read, the resonant sensors have a much higher output (like 10x higher) than the non-resonant ones.
It does. All of the audio samples I've taken of resonant VS non-resonant sensors seem to suggest the same thing.
88 RX-7 TII - MS2 Extra 1.0.2
68 Mustang 351C - MS3X
88 Volvo 245 - 2JZGTE VVTi powered, MS3X + MSGPIO Mshift controlled
savagerocco
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Re: Knock module for MS3 (beta test)

Post by savagerocco »

Hurry up and get these tested......This is something I have been waiting for for far too long......
Brent Savage
life behind the zion curtain
90 audi RS2 20VTQ 6sp MS3, MSX COP and Sequential and now MAF
87 Scirocco 2.0 ABA 16v EIP tubular cast MSII COP
86 Audi 4K20VTQ MSII
90 Audi 90 sedan 3.6l DOHC V8TT (project car)
89 VW cabbie (bitch basket) 2.0 ABA Turbo MSII
mega_user
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Re: Knock module for MS3 (beta test)

Post by mega_user »

As said wasted spark firing two coils at once and sequential fuel is supported for 12 cylinders.

HeinrichG wrote:
jsmcortina wrote:I don't think there are enough pins on the MS3 to be able to do that. Certainly the current design doesn't permit that.

James
That's really pity :( :( :(

Regards,
Heinrich
Yetidragon
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Re: Knock module for MS3 (beta test)

Post by Yetidragon »

I am just about to megasquirt3 my MX5 (picking the kit up from the post office tomorrow) and i am very interested in adding this to my setup.
Definately want to be in the next batch please :D
Metaworld
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Re: Knock module for MS3 (beta test)

Post by Metaworld »

gross polluter wrote:Not having much luck with mine. Seems like there needs to me more attenuation before the signal gets to the ic, at least with the factory 2JZ knock sensors. With the gain set to 1 the knock gauge always reads 101% with the gain at minimum the knock gauge bounces between 50% and 70% at idle and reads 101% off idle. Haven't had much time this week to tinker beyond installing the module and running it as-is.

Any advice on setting integrator time constant? Can't really figure that one out.
Set your Gain Higehr. Gain is the Level of the Knock Sensor Voltage. The Integrator Time is the Time which the TPIC Sampels Knock Signals. If the the Int/Hold Signal comes to the Tpic it starts to count. So you longer set your Integrator much more Noise you get.

Maybe James Could Tell me the something about his Pinout for the TPIC to MS

Pin 7 Int/Hold ->MS
PIN 8 CS -MS
Resonator Frequenz on Pin 9+10
Pin 11 SDO (MISO)
PIn 12 SDR (MOSI)
Pin 13 SCLK (SCK)

Where is the Test Pin wired?
Here is the Layout which is Designd from a friend of mine Peter Diener. We use this for external solution an listing to the Knock Sensor.

http://www.mikrocontroller.net/wikifile ... or_sch.pdf

Kind Regards
jsmcortina
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Re: Knock module for MS3 (beta test)

Post by jsmcortina »

I don't have the schematic to hand, but I'm pretty sure that 'Test' is NC.

James
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Metaworld
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Re: Knock module for MS3 (beta test)

Post by Metaworld »

Did you use the Adavanced SPI Mode to get the Knock Level? Maybe it would be possible that you could send me an pinout to connect my TPIC to MS3 or an schematic.

Kind Regards Stefan.
tpsretard2
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Re: Knock module for MS3 (beta test)

Post by tpsretard2 »

hi James, got her back up and running, i also got the knock board installed..

at idle with my noisy engine it will flutter between 10-20, and driving it will be 40-50.
will get all the settings, but from the time the engine is started, the knock indicator comes on, no matter what settings i use it will not go off.

?? Is this normal behavior.
elaw
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Re: Knock module for MS3 (beta test)

Post by elaw »

Can you post your msq file?
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
tpsretard2
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Re: Knock module for MS3 (beta test)

Post by tpsretard2 »

here it is..
elaw
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Re: Knock module for MS3 (beta test)

Post by elaw »

Well your settings look pretty good, although if knock is running 40-50 when driving (and the engine is not knocking), you might want to raise the thresholds a bit - I'd try increasing them by 10 or even 20 percent at all RPMs.

Also I wonder if this could be a quirk related to the fact that your maximum retard is set to 0? Have you tried setting it to a > 0 number?

One thing I've noticed on my setup is that I get a single very high spike in the knock number at startup - if yours is doing the same thing that might explain why it's showing knock from the moment the engine starts.

If you continue to have trouble, you probably should take a data log and post it too - that might help identify the problem.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
tpsretard2
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Re: Knock module for MS3 (beta test)

Post by tpsretard2 »

yea i tried more than 0,

but now you have me thinking, i can swing as much as 60 when cranking..
The clearances are VERY VERY loose on this engine, so it is very noisy, even with the 60wt oil.

Could this be some area that can be worked on then, the indicator i would not of though you would want staying on at all. maybe a delayed turn off, but not a stay on all the time.

also the knock counts, i am amusing this how many time is crosses the set threshold right ??
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Re: Knock module for MS3 (beta test)

Post by jsmcortina »

tpsretard2 wrote:Could this be some area that can be worked on then, the indicator i would not of though you would want staying on at all. maybe a delayed turn off, but not a stay on all the time.
The current ini just turns the light on if "knock" is non-zero.
also the knock counts, i am amusing this how many time is crosses the set threshold right ??
Yes.

James
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