60/2 vs 60/2 VW mess

[rusefi]

We have two versions of 60/2 trigger - "60/2" and "60/2 VW"

looks like this is due to misunderstanding of how VR works, one is theoretical nice 60/2 Hall while the other one is real 60/2 VR signal

See also #707

[rusefi]

See https://github.com/rusefi/rusefi_documentation/raw/master/triggers/hall_vs_vr.png at https://rusefi.com/forum/viewtopic.php?f=2&t=1519

[rusefi]

Matthew Kennedy 9:39 PM
a hall sensor engine will work fine with the VR config (ie, only decode one edge)
event every 6 degrees vs. event every 3 degrees isn't a difference, other than sucking up cpu cycles
new messages
whatever edge and type of sensor you have, if you see gap ratios of 1-1-1-2-2-1-1-1 instead of 1-1-1-3-1-1-1 then the polarity is wrong
russian 9:42 PM
hold on
do you mean
1-1-1-2-2-1-1-1 means polarity is wrong
and in case of wrong polarity, you will see 1-1-1-2-2-1-1-1?
Matthew Kennedy 9:42 PM
Yes

[rusefi]

INCORRECT VR wiring

CORRECT VR wiring

this is from my M73 confirming above opinion.

Top picture is wired INCORRECTLY while bottom picture is wired properly

[OrchardPerformance]

Should these be referred to as 60-2 High gap and 60-2 Low gap.
Then it identifies the two traces by the physical feature of the wheels.
I think one signal comes from each kind of trigger wheel gap.

[OrchardPerformance]

Low gap
60-2 VW pattern

[OrchardPerformance]

high gap
Universal True 60-2 pattern

"trigger wheel wont work with a hall sensor since the "half depth" missing tooth will sometimes be seen as one long tooth."

[OrchardPerformance]

https://www.hpacademy.com/forum/general-tuning-discussion/show/custom-60-2-wheel-suitable-tooth-dimensions

Although I would trash talk their comment about BMW and others being incorrect, that's a bosch wheel and bosch pattern, I would think they would get their own invention right.

[rusefillc]

Status update: we are still a bit confused :)

But at least we now have nicer wheel shapes documentation at

https://github.com/rusefi/rusefi/wiki/All-Supported-Triggers#vw-602
and
https://github.com/rusefi/rusefi/wiki/All-Supported-Triggers#602

[mck1117]

Neither of those patterns matches the Renault pattern. The renault pattern missing tooth looks similar, but the first tooth after the gap is longer.

[rusefillc]

@mck1117 FYI

[mck1117]

Nik's trigger looks like this:

[mck1117]

My missing tooth (missing gap) looks like this:

[mck1117]

As far as I can tell, these are the same, but one is inverted from the other.
But because of how the max992x works, you can't just invert in software, they actually require opposite sensor polarity.

[mi-hol]

My take from above comments is:

• there is no real technical issue but just unclear documentation

Is this correct understanding?

[rusefillc]

Not sure. Documentation implies user would manually locate documentation and understand it, I would prefer that we do smarter things like auto-detect the issue etc.

[mi-hol]

I would prefer that we do smarter things like auto-detect the issue etc.

While I understand and support this view, realistically auto-detect trigger pattern seems a too big task considering the currently available resources to fix this within a reasonable amount of time. Auto-detection had apparently no activities since 2017!
A viable short term fix to move forward with rusefi/rusefi_documentation#459 seems the approach with enhancing documentation only.
I'd be happy to be proven wrong though

[rusefillc]

M73 with VW trigger

https://github.com/rusefi/rusefi/wiki/Trigger-Configuration-Guide#determine-correct-polarity says it's flipped

[rusefillc]

same M73 engines now flipped wires - should be proper polarity now

[rusefillc]

https://rusefi.com/forum/viewtopic.php?p=49489#p49489