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Crank pull-up

 
Old 12-02-2018, 06:04 PM
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Default 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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Old 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.
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Old 12-02-2018, 06:18 PM
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Originally Posted by Joe Perez View Post
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.
The cam signal from the JimStim doesn’t require a pull-up, but the crank signal does. Does that mean my board has a pull-up on the expander card, but not the main board?

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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Old 12-02-2018, 06:21 PM
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Also, what jumpers are recommended on the 3.57 board. Or rather, where should I look to find this info? MS Manual?
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Old 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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