Crank pull-up
12-02-2018, 06:04 PM
#1
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Crank pull-up
I recently got a used pre-assembled MS3X. It ran an NB1 previously. On my JimStim I can only get a crank signal if I pull up the crank signal to 5V. Is this normal?
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12-02-2018, 06:13 PM
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Yes.
Both the crank and cam sensors on the NB are of the open-collector output type. This means that they provide a closure to ground when active. As such, you must provide an external pullup voltage via a resistor (1k is typical) to their output pin in order to produce a useful signal.
Both the crank and cam sensors on the NB are of the open-collector output type. This means that they provide a closure to ground when active. As such, you must provide an external pullup voltage via a resistor (1k is typical) to their output pin in order to produce a useful signal.
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12-02-2018, 06:18 PM
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Yes.
Both the crank and cam sensors on the NB are of the open-collector output type. This means that they provide a closure to ground when active. As such, you must provide an external pullup voltage via a resistor (1k is typical) to their output pin in order to produce a useful signal.
Both the crank and cam sensors on the NB are of the open-collector output type. This means that they provide a closure to ground when active. As such, you must provide an external pullup voltage via a resistor (1k is typical) to their output pin in order to produce a useful signal.
The NB crank sensor doesn’t have its own pull-up from what you said. I wonder then how the PO ran their car.
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12-02-2018, 06:38 PM
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From the manual I’m reading that R57 needs a 1k essentially.
So, just to be sure the Miata’s hall sensor on the cam doesn’t have an internal pull-up, and therefore I need R57.
Adjustment of R52 and R56 doesn’t affect that I need a pull-up.
Im just really confused how this board ran an NB lol.
http://www.msextra.com/doc/general/t...7.html#vrlogic
Miata's use a Hall sensor right? Therefore a pull-up is required.Edit -
I don't have my iron on me right now, so I tried touching a 1k across two pads. Didn't work. Probably not the best way to go about it, just figured I'd try.
Last edited by ByteVenom; 12-02-2018 at 07:01 PM.
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08-17-2021, 09:35 AM
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Sorry for the bump, I just have a pre-assembled MS3X and trying to figure out if I need to modify anything other than the 12V flyback clamp.
Did you end up needing a 1k resistor across R57?
Did you end up needing a 1k resistor across R57?
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