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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Fri Jan 10, 2014 9:51 am 
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abecedarian wrote:
Appropriate for an ECU / controller actually; might give the 5634M a run for the money. ;)


Watch it there! ;)

I don't know how to ell you this but your "simple map emulator" project seems to have gone completely off the rails :)


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Fri Jan 10, 2014 9:02 pm 
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mk e wrote:
abecedarian wrote:
Appropriate for an ECU / controller actually; might give the 5634M a run for the money. ;)


Watch it there! ;)

;)

Quote:
I don't know how to ell you this but your "simple map emulator" project seems to have gone completely off the rails :)

No kidding, eh? :lol:

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My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Sun Jan 12, 2014 11:38 pm 
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It's looking like I could use the 32 tooth wheel with both VR pickups to generate quadrature A & B signals, and use an existing flywheel VR to give an "index" pulse, meaning 2 MAX9926 chips, and the 4th 9926 input could signal engine phase from a cam NE sensor.

Nah!

I'll use this board to condition signals for the low-cost ECU Rob releases. ;)

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/me goes off to the corner feeling like Jerry Springer with a mullet.

My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Mon Jan 13, 2014 10:55 am 
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abecedarian wrote:
It's looking like I could use the 32 tooth wheel with both VR pickups to generate quadrature A & B signals, and use an existing flywheel VR to give an "index" pulse, meaning 2 MAX9926 chips, and the 4th 9926 input could signal engine phase from a cam NE sensor.

Nah!

I'll use this board to condition signals for the low-cost ECU Rob releases. ;)


What?????

Was that even English? :lol:


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Mon Jan 13, 2014 12:23 pm 
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mk e wrote:
abecedarian wrote:
It's looking like I could use the 32 tooth wheel with both VR pickups to generate quadrature A & B signals, and use an existing flywheel VR to give an "index" pulse, meaning 2 MAX9926 chips, and the 4th 9926 input could signal engine phase from a cam NE sensor.

Nah!

I'll use this board to condition signals for the low-cost ECU Rob releases. ;)


What?????

Was that even English? :lol:
Matter of fact, yes. ;)

Quadrature encoding is having two signals slightly out of phase, typically referred to as A & B. With either signal, you can determine rotational speed and depending on which signal occurs first, you can determine the direction of rotation. Add in a third signal, an index, and you can determine absolute position.

So the implication was that I could use the gear you fabricated for me and the two pickup VR's to be the A & B signals, and an existing VR around the flywheel for the index signal. Since I also have a camshaft position sensor, that could determine engine cycle / phase (intake, compression, power, exhaust) to help schedule firing fuel injectors and ignition.

But then I realized it's a silly idea for me to post that so I'll wait for you to convince Rob to release an obscenely low-priced ECU.
8-)

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/me goes off to the corner feeling like Jerry Springer with a mullet.

My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Mon Jan 13, 2014 1:08 pm 
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abecedarian wrote:

Quadrature encoding is having two signals slightly out of phase, typically referred to as A & B. With either signal, you can determine rotational speed and depending on which signal occurs first, you can determine the direction of rotation. Add in a third signal, an index, and you can determine absolute position.

So the implication was that I could use the gear you fabricated for me and the two pickup VR's to be the A & B signals, and an existing VR around the flywheel for the index signal. Since I also have a camshaft position sensor, that could determine engine cycle / phase (intake, compression, power, exhaust) to help schedule firing fuel injectors and ignition.

But then I realized it's a silly idea for me to post that so I'll wait for you to convince Rob to release an obscenely low-priced ECU.
8-)


I was having trouble figuring out how any of that that helped you? You know the rotation direction and the missing tooth gives the index point right?

So what new or useful information would you be adding?

I am pushing Rob to keep the price low. My personal goal is to keep pushing until I hear something right around $250.....we'll see how that goes :)


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Wed Jan 15, 2014 12:29 am 
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mk e wrote:
I was having trouble figuring out how any of that that helped you? You know the rotation direction and the missing tooth gives the index point right?

So what new or useful information would you be adding?

I am pushing Rob to keep the price low. My personal goal is to keep pushing until I hear something right around $250.....we'll see how that goes :)

The TMS570's N2HET (High Efficiency Timer) is comparable to eTPU, intended for automotive shaft position sensing (motor or engine), it gives, more or less, the same information.

Now the following is hypothetical and please correct me if I'm wrong but, eTPU uses one crank sensor, and counts teeth while checking for missing tooth and cam signals. It can't tell if the engine is running backwards even if it receives cam and missing tooth signals unless it verifies those are properly phased, which could take 2-4 revolutions dependent upon what position the crank stopped at and cranking speed.

Not a problem for most engines since the fuel is on one side and exhaust on the other so it's not going to be sucking fuel in through the exhaust, but if injectors happen to fire at an open intake valve and the spark plug fires while the intake valve is open... or some other physical engine characteristic like hydraulic belt / chain tensioner bleeds down and valve / piston interference occurs, that could cause damage if the engine is turning in reverse, even by hand...?

A two stroke, that can conceivably run backwards, could have problems. Since I have a motorcycle, and a few friends with them, I started thinking.

With quaduature encoding like I mentioned, the ECU could detect the engine turning backwards within a few degrees of rotation, limited only by the spacing between 2-4 teeth, without an index, cam or missing tooth signal. It could then re-phase the ignition and injection pulses to compensate if for some reason the user wanted the engine run backwards, or kill the engine if reverse rotation is not permitted.

Might be something to consider for O5E code that checks missing tooth before and cam trigger or vice versa should be checked, with fuel and ignition disabled until rotational direction is verified. After that, a simple 'rotDirVerified = 1" or "true" can be set and checking skipped.

If you've thought of that already, my apologies.


I'm not saying I'm going to pursue this, but am not saying I'm not either, if for no other reason than I have a board that can conceivably do this. For now it's mostly a thought experiment.

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My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Wed Jan 15, 2014 10:49 am 
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There are two stroke snowmobiles that run the engine in reverse instead of having a reverse gear.

It is diffucult to mount the cam sync sensor on a two stroke..


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Wed Jan 15, 2014 1:00 pm 
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glenn wrote:
There are two stroke snowmobiles that run the engine in reverse instead of having a reverse gear.
Didn't know that.

Quote:
It is diffucult to mount the cam sync sensor on a two stroke..
Didn't think of that. :oops:

I'll go back to doing over here things. ;)

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My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Thu Jan 16, 2014 12:16 am 
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Might be worth noting that some 2 strokes use rotary valves so have to have some sort of "cam" action going on. Detroit Diesel had 2 strokes with camshafts that opened valves and timed fuel injectors too, but those were also supercharged....

Multiple DD engined trucks delivering fuel to gas stations experienced engine 'over speed' and piston launches when leaving the engine running while putting fuel in the underground tanks: the engine was running and inhaling gasoline vapors and couldn't be shut off. It's now a requirement they turn the engine off when delivering fuel to the stations.

And having said that, I'm back to those things over "here".

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/me goes off to the corner feeling like Jerry Springer with a mullet.

My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Thu Jan 16, 2014 9:18 am 
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I didn't know about the sleds running backwards either...makes sense though.

For the 4 stroke world that o5e is aimed at I just don't see any need to "know" what direction is't cranking. I suppose if it's going backwards the cam pulse will be out of the acceptance window so no fuel/spark

I think you worry too much :)


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Thu Jan 16, 2014 3:29 pm 
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mk e wrote:
I think you worry too much :)


I accept that.
Image

*cheap Sons of Anarchy reference.
:D

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My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Sun Jan 19, 2014 7:45 pm 
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Anyhow, been bored... and for no other reason than to have fun with Mark... ;)
(ignore the air-wire: those two pins have shared functionality)
About 4" x 4", not including the connector protrusion.

Attachment:
HEFI_1-19-14.jpg
HEFI_1-19-14.jpg [ 119.83 KiB | Viewed 8817 times ]


Hercules (TMS570) board on the left, bottom layer is ground, left is 3v3 for the MCU, right is 5v0. "Stray" trace up and around the left and top is 5v for the LDO; melds into the 5v0 layer.

Op-amp at the lower left to divide 5v0 signals: 5v reference, TPS, MAP, IAT. 2nd op-amp (not shown, but basically duplicate the other) for CLT and other uses could go top-right, along with CAN I/F. Injector and ignition drivers could go top left.

*edit to correct a dyslexic moment and marvel at Mark's lack of commentary. ;)
Last paragraph should read:
2nd op-amp (not shown, but basically duplicates the other) for CLT and other uses could go top-left, along with CAN I/F. Injector and ignition drivers could go top right.

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/me goes off to the corner feeling like Jerry Springer with a mullet.

My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Tue Feb 25, 2014 12:31 am 
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Well... been a while and have changed a few things, and still have some routing to do.

As it stands now:
5v / 4A power supply (lower left, location will probably change), still need to consider reverse voltage connection and other protection. It's based around a TPS54560 regulator.

Senses TPS, IAT, CLT, MAP, oil pressure, fuel pressure, O2, 2 VR sensors (still have to lay those out). Using resistor dividers to drop 5v to something the ADC can handle, followed by op-amp voltage followers / unity gain buffering to feed ADC. Also, the 5v rail will be sampled and converted to use as the 'reference' for the sensor signals.

4 injectors (high-Z) and 4 ignition (logic level, i.e. LS1/2) are planned.

3 SPI (already routed to connector) and 1 LIN and 1 CAN (maybe two) are planned. SPI will probably drive the dashboard and, along with LIN, provide for some expansion / additional capabilities.



Attachment:
2_24_2014_render_B.png
2_24_2014_render_B.png [ 29.98 KiB | Viewed 8637 times ]


When O5E code is good and working, I'll start looking at porting it to TMS570.

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/me goes off to the corner feeling like Jerry Springer with a mullet.

My O5E candidate: 1982 Honda CX500TC motorcycle.


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Fri Feb 28, 2014 7:07 pm 
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Lets see

:geek: :geek: :geek:
That is looking a whole lot more like an ECU than a MAP emulator

:o


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 Post subject: Re: MAP sensor emulator... of sorts
PostPosted: Mon Mar 03, 2014 10:43 am 
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mk e wrote:
Lets see

:geek: :geek: :geek:
That is looking a whole lot more like an ECU than a MAP emulator

:o

Well, I think you're right. But like I said...
"Anyhow, been bored... and for no other reason than to have fun with Mark... ;)"
and
"For now it's mostly a thought experiment."

So, it's more of a mental diversion than anything real though, as of yet.

I've also one of these kits which has an LM3S8962 @ 50MHz / 256KB flash / 64Kb SRAM on the big board and an LM3S2110 @ 25MHz / 64KB Flash / 16KB SRAM on the little one, with CAN communications between them (the 2x5 pin headers on the boards).
Image

Getting all these free 'kit' is corrupting me. :D

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My O5E candidate: 1982 Honda CX500TC motorcycle.


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