Just completed installation: RPM erratic

Race Capture Pro hardware installation- power, wiring, physical installation, etc. See the dedicated forum for Sensor related topics

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alangbaker
Posts: 14
Joined: Sun May 03, 2015 8:20 pm

Just completed installation: RPM erratic

Post by alangbaker »

Well, after some trials and tribulations finding all the correct software and firmware (the link to the software on the wiki doesn't include later versions available through race-capture.com), I've got my RaceCapture/Pro MK2 installed in my Formula Ford and (I think) correctly wired to receive an RPM signal via a CoilX.

And I do appear to be getting an RPM reading.

But:

1. With the car off, it still reads 1410 rpm.

2. While the RPM does appear to read correctly, I get flashes to ridiculously high numbers. It will go from reading the (correct) 2000 rpm, and bouncing erratically to numbers up above 10000 rpm as high as 62000 rpm +.

What's going on? Anyone?

brentp
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Posts: 6277
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi Alan,

It seems there's some ignition noise that's overwhelming the hardware filtering built in to CoilX.

We're working on a firmware update that will add some additional software filtering on top of what's in CoilX. it's fairly complicated as we have to account for rising edge / falling edge type triggers and being able to program the noise filter duration (the period where we ignore the signal, masking noise pulses).

If you're familiar with RC filter circuits you might be able to fashion a low pass filter between CoilX and RCP that would further reduce the noise level. you want to target about a 150Hz cut off frequency.

If you're not comfortable with this, ping us back here and we'll help with a circuit design.
Brent Picasso
CEO and Founder, Autosport Labs
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