Knock Detection with variable sensitivity over RPM

A forum for discussing the MegaSquirt related (but non-B&G) board development, assembly, installation, and testing.

Moderators: jsmcortina, muythaibxr

Locked
tobmag
Helpful MS/Extra'er
Posts: 81
Joined: Sat Feb 20, 2010 7:26 am
Location: Sweden

Re: Knock Detection with variable sensitivity over RPM

Post by tobmag »

jsmcortina wrote:Try this:
http://www.viatrack.ca/

James

Any good references on this one? quite simple with a LED only, cant hang on my MS since Im out of free pins....

BR//Tobmag
Last edited by tobmag on Wed Jul 21, 2010 12:44 am, edited 1 time in total.
paulpug
Helpful MS/Extra'er
Posts: 131
Joined: Wed Nov 11, 2009 9:12 am

Re: Knock Detection with variable sensitivity over RPM

Post by paulpug »

hi,
i was actually thinking along the lines of what these others persons are doing ,i was thinking they were developing something that can be
used with MS.

Paul
dirtytorque
Helpful MS/Extra'er
Posts: 50
Joined: Thu Mar 12, 2009 11:01 am
Location: Berkshire UK

Re: Knock Detection with variable sensitivity over RPM

Post by dirtytorque »

tobmag wrote:
jsmcortina wrote:Try this:
http://www.viatrack.ca/

James

Any good references on this one? quite simple with a LED only, cant hang on my MS since Im out of free pins....

BR//Tobmag
Did my first test in anger on this today under some hard acceleration etc.
I recommend it.
On a couple of occasions the Knock indication LED in the cabin came on pretty much under the conditions that I expected.I was accelerating hard up a slight gradient with the throttle cranked open with the charger pumping into the engine.
On the log below you can see that the advance table was trying to run about 32 degrees of advance btdc in the given rpm and boost pressure range that the engine was operating in.This got wound down to about 20 degrees btdc,at which point no more knock occured.(The red curve shows the knock events.More specifically it shows the amout of retardation that is being subtracted from the ignition tables current value).
Blue line= boost.yellow line= rpm,pink line air/fuel ratio and green = ignition advance.
Really happy with the system as with the aid of the log files you can get an accurate reading of where your engine is knock limited and by how much.Would be interesting to see if something like aquamist could "quench the fire".
tobmag
Helpful MS/Extra'er
Posts: 81
Joined: Sat Feb 20, 2010 7:26 am
Location: Sweden

Re: Knock Detection with variable sensitivity over RPM

Post by tobmag »

Thanks for the feedback. Unfortunatly I cant hook up the knock detector to my MS2 since I'm using 6 ignt outputs..
But you said that the LED comes on accuratly according to your log so guess I have to do it the manual way and correct the timig table manually :cry:

BR//Tobmag
dirtytorque
Helpful MS/Extra'er
Posts: 50
Joined: Thu Mar 12, 2009 11:01 am
Location: Berkshire UK

Re: Knock Detection with variable sensitivity over RPM

Post by dirtytorque »

cool,well doing it manually with the LED isn't ideal but its better than nothing. 8)
And you have it for later if your able to get around yourhardware limitations.
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Good Work DIY torque!!
dontz125
Super MS/Extra'er
Posts: 4200
Joined: Mon May 11, 2009 7:14 pm
Location: York, ON
Contact:

Re: Knock Detection with variable sensitivity over RPM

Post by dontz125 »

Tobmag - take a look at this idea I threw out a while back. It needs to be checked by someone who knows what they're talking about, but I think it should work.

http://www.msextra.com/forums/viewtopic ... 01&t=35993 - Use PE0 or PE1 as knock input pin
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
dontz125
Super MS/Extra'er
Posts: 4200
Joined: Mon May 11, 2009 7:14 pm
Location: York, ON
Contact:

Re: Knock Detection with variable sensitivity over RPM

Post by dontz125 »

Ok - Turbo355 has modified the code to use my thought and compiled it - see the thread above.
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Variable sensitivity over rpm...
Last edited by HOODEY on Sun Nov 13, 2011 8:59 am, edited 2 times in total.
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Automatic Setting of References levels aka auto calibration completed. Phew!!!!

Monitor digital sets the threshold levels for you. It learns the noise profile of the
engine and set the reference level to hug the noise profile.
420aRaf
Helpful MS/Extra'er
Posts: 59
Joined: Thu Feb 19, 2009 4:33 pm
Location: Staunton, VA

Re: Knock Detection with variable sensitivity over RPM

Post by 420aRaf »

HOODEY wrote:Automatic Setting of References levels aka auto calibration completed. Phew!!!!
I’ve been working on this route a lil recently with the dspic. Do you have a video of it or an oscilloscope shot?
-Rafiel
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

So you have jumped from 8bit to 16bit and 16f to DSPIC..chaaa!!!! :mrgreen:
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Upgrade.
Last edited by HOODEY on Sun Nov 13, 2011 8:59 am, edited 1 time in total.
a73camaro
Experienced MS/Extra'er
Posts: 231
Joined: Fri Oct 08, 2004 6:44 am
Location: Dillon, CO

Re: Knock Detection with variable sensitivity over RPM

Post by a73camaro »

HOODEY wrote:Upgrade.

Two 5 volt output for Knock.
4 order band pass filter programmable and amplifier for listening via head phones.
Power Driver to Drive Light or high Power
WOW - more pots than resistors. Gives you lots of "tunability" :mrgreen:
MSII v3.0, Extra 3.0.3s
420aRaf
Helpful MS/Extra'er
Posts: 59
Joined: Thu Feb 19, 2009 4:33 pm
Location: Staunton, VA

Re: Knock Detection with variable sensitivity over RPM

Post by 420aRaf »

HOODEY wrote:Upgrade.

Two 5 volt output for Knock.
4 order band pass filter programmable and amplifier for listening via head phones.
Power Driver to Drive Light or high Power
Man that’s a lot of components. Looks good though, any reason why you marked off the name of the pic? I’m using the DSP because every pin is an interrupt and I can choose the interrupt I want on that pin. It doesn’t have an EEPROM it just has flash, which is fine because it’s faster. I also love the 32 and 16bit bit timer which makes things stupid easy and more precise but its not so easy setting everything up and it runs on 3-3.6v with only several pins 5v tolerant. I try to stay away from 32bit math. Speaking about EEPROM, are you still writing values to it??? You know that takes several ms right?? Have you tried writing to flash? After I make my board I will post it up.

EDIT: NVM writing to flash, i forgot it has a limitation....."write life"
-Rafiel
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Yeah tons of pots.
Last edited by HOODEY on Sun Nov 13, 2011 9:00 am, edited 1 time in total.
420aRaf
Helpful MS/Extra'er
Posts: 59
Joined: Thu Feb 19, 2009 4:33 pm
Location: Staunton, VA

Re: Knock Detection with variable sensitivity over RPM

Post by 420aRaf »

Data Logging is written to RAM and then copied to Flash.
I need a better way to connect the LCD (16 pins) wish I could purchase a ribbon cable already solder to connector.
If you plan on doing any type of logging you might want to look at a FRAM, serial EEPROM or SD card instead of writing the chips flash. I was wondering how long it was taking you to send the bits to LCD; I figured you were using 8bit mode and not 4. Why not use a multi slave SPI for a LCD/GLCD and the Knock chip if your worried about wiring?
-Rafiel
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Putting some cloths on
Last edited by HOODEY on Sun Nov 13, 2011 9:00 am, edited 1 time in total.
davcol
Experienced MS/Extra'er
Posts: 160
Joined: Tue Dec 22, 2009 6:12 pm

Re: Knock Detection with variable sensitivity over RPM

Post by davcol »

Hello , i love your developement on this topic , the hold idea of a knock detection system that can operate base on RPM is a brilliant thing to do , that make this system operates more accurately when detecting knock.
You see recently i purchase a knocksense unit from viatrack.ca ,its a nice unit but i just cant seem to get it to operate the way i wanted it to ,it just keep picking up a lot of engine vibration as early as 4000RPM all the way to 7000RPM , i have tried the attenuation mode with the variable resistor to reduce the sensitivity but still it did not work out the way wanted it to , My engine is 3rd GEN 3SGTE engine running 8.0:1 compressoin ratio and i have it tune out properly on the dyno , the dyno shows no knock when tuning was completed but with the knocksense unit it keep on registering that the engine is knocking, i just cant seems to get this unit tuned out properly so i can tuned with a more aggressive street tuning for my car.
When i saw this discussion on variable sensitivity knock detection system you guys developed i was very interested in it and hoping that you can complete the great work, so my questian is , is this project completed or it is still in testing process :RTFM: , PLEASE .
But is there a way that i can get my knocksense unit to work properly :( like it to know the difference between engine noise and when the engine is actuately knocking, my friend has AEM management system ,he was able to plot is knock sensor frequency by driving and properly tuned the engine so there is no knock for the hold rpm range and then tells the AEM that any thing over these set points should consider knock, can we have megasquirt operates like this?
m2 extra v3.57 3sgte full sequential injection V1.1A P&H Board
full sequential spark low current c.o.p.
holset turbocharger
HOODEY
Helpful MS/Extra'er
Posts: 115
Joined: Sat Feb 21, 2009 5:18 pm

Re: Knock Detection with variable sensitivity over RPM

Post by HOODEY »

Finally upgraded processor two steps. Pic18f452 to pic18f4520 to pic18f4525.
Last edited by HOODEY on Sun Nov 13, 2011 9:01 am, edited 1 time in total.
Locked