CAM input JS10 U3 problem

[MS2tester]

excuse me!!!!!!
start winging it!!!!
i appreciate your opinion
but i do feel a little insulted here

manual as of 08-12-2014

5.2.14.3
Adding a cam sensor input - hall or logic sensor
This option uses the spare opto-isolator on the mainboard for the cam input and matches the polarity inversion
of the VR/universal tach input.
This section is for sensors as covered in 5.2.3 that put out a 0-5V signal.
a) The OptoIn pad should be connected to a spare pin on the main DB37 connector (e.g. SPR3)
b) Connect OptoOut to JS10 (ensuring that nothing else is connected.)
c) Jumper XG1 - XG2
d) Check that R12 is a 390R to 470R resistor, replace if not.
e) -not required-
f) -not required-
g) Ensure that C30 is not fitted.

The gear-tooth sensor is a variant of the hall sensor - the key difference is that it has a magnet built into it and
switches when close to steel, no external magnets are required. This makes them very easy to use. These are
almost exclusively a three wire sensor. In CAS (crank angle sensor) units a multi-plug may be used to combine
multiple sensors. The sensor itself acts like a switch to ground when close to steel.
Just like hall sensors, the gear-tooth sensor may be open-collector or have a built-in pull-up. Refer to sections
5.2.3 and 5.2.4 for more detail.
The image above shows the Honeywell 1GT101DC gear-tooth sensor, this works well for single tooth or half-
moon cam wheels, but is not suitable for missing-tooth wheel installs.

Hall on VR input so basicly a 5 volt pull up
c) Install a 1k resistor (any value 470R - 2k2 is likely OK) in the proto area. Connect one end to the 5V hole and
join the other end to VRIN with a jumper wire.

add to that like mentioned in my above post
that the majority of Hall pull schematics are displayed with a 1 Kohm pull up
now i am not trying to insult anybody here
but i think in the majority of cases people will build the setup as i did
you get basicly the same reading the manual
i do think a lot of fustration can be prevented here
if you are either more clear in the build manual as to the preffered circuit
or better yet clarify the difference between the R12 values
as it clearly has a great impact on whether it will work or not!!!

ok enough venting here

[DaveEFI]

Seems a lot of confusion over making an LED flash...

[slow_hemi6]

I see you do like to use a lot of quoting when you feel like you have done everything right and I am the one who is wrong. The problem you have here is in not just the reading, but mostly in the understanding.
From the above. 5.2.14.3

This section is for sensors as covered in 5.2.3 that put out a 0-5V signal.

Flag No1 your sensor clearly does not do this. So therefore the instructions underneath do not apply to you and you must look to the previous section. You must have done so, as you included sections in your quote. So off we go to 5.2.3 and we find this.

There are two main categories of hall sensor • open-collector (needs a pull-up resistor) • built-in pull-up resistor (covered in section 5.2.4)

This is where your sensor type and operation is defined.
So unfortunately there really are no open collector to opto input switching instructions in the manual. There are in the old manuals but I guess they have not been included in the new manuals. You get that sometimes. James is always ready to amend manuals when issues are raised, in my experience.
So in reality here is the point where you are meant to go and seek advice from the forum etc. Not understanding 5.2.14.3 and continuing on with the instructions is not mine, James or the manuals problem.

Still even though it is not linked or directed to by any of the above, you also include 5.2.5 because you recognized the device.

Just like hall sensors, the gear-tooth sensor may be open-collector or have a built-in pull-up. Refer to sections
5.2.3 and 5.2.4 for more detail.

So that just loops you back to no specific instructions for your set up so you need to seek advice before.... yup here it is, "winging it"

[MS2tester]

I give up

[DaveEFI]

No need to give up. All that does is hurt yourself.

The important bit is the current flow through an LED - not the voltage. The coupler is pretty tolerant - aim for about 20 mA. Thing is both the pullup resistor and R12 effect the current to the LED.

I'm also not sure if you're using 5v or 12v to supply your hall sensor?

[slow_hemi6]

The instructions you have posted above are for a hall sensor connected to the VR/universal input (ie crank input). Not really applicable to the opto input circuit. As I said the new manual is lacking the open collector hall to opto, cam input circuit.
This is from the old manual http://www.msextra.com/doc/general/tach ... #spareopto you can see there is no 1k pull up connected at the sensor itself. R12 is the pull up and it's value is appropriate for the chosen supply voltage.

[MS2tester]

well that sort of was the point i was trying to make

i have it working
just not with the resistors mentioned in the schematics

second what i was trying to make clear
that people god forbid changing over from another/aftermarket ECU
in very likely hood will have a 1 Kohm resistor installed in the wire loom

now you could say people you should have come to the forum
but i know now from experience from trying to sell the unit and the questions asked
people are not that well educated
and most will chuck the MS and say it,s crap (read this on quite some forums)
which is a big shame

all i am saying is that you could view the 1 Kohm pull up as the car/industrial norm
so it might be handy to adjust the R12 Ohm value accordingly ( 330 Ohm )
and if as you say up to 20 Mamp is well within the norm
this might be the wise thing to do (you usually end up with extra,s )
as from my readings with both 5 volt and 12 volt the Mamp stay well within that 20 Mamp window

that,s all i was trying to make clear

[jsmcortina]

so it might be handy to adjust the R12 Ohm value accordingly ( 330 Ohm )(

The default value is actually 390R.

James

[MS2tester]

so it might be handy to adjust the R12 Ohm value accordingly ( 330 Ohm )(

The default value is actually 390R.

James

would that still work with D1 and D2 installed ?
and say C30 is still installed?