MS3 speedo output

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MS3 speedo output

Postby arran » Tue Sep 19, 2017 11:38 pm

Hey all,
I'm thinking about using an MS3 feature in Speed and Gear Sensor menu "VSS output". Hopefully a really simple question: it does work OK yes?

Just thought I'd ask about any known problems before I spend a buch of time and a little bit of money on installing stuff in the car to a certain design and then find that something is broken.

I want to replace the speedo cable in my RX7 with a speed sensor (I have one that fits the gearbox). The pulse train is sent to MS3, and with any luck I can scale the frequency of VSS out for easy calibration. VSS out would go to an Arduino, there are libraries available for a conversion to PWM which is then a no brainer to drive a brushless motor which turns the speedo mech.

Thanks
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
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Re: MS3 speedo output

Postby edgedj » Fri Oct 13, 2017 2:55 pm

yup, it works :-)
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Re: MS3 speedo output

Postby jsmcortina » Sat Oct 14, 2017 4:13 am

arran wrote:VSS out would go to an Arduino, there are libraries available for a conversion to PWM which is then a no brainer to drive a brushless motor which turns the speedo mech.

You can use the MS3 to generate a PWM output based on VSS already. Use Generic PWM with a curve and VSS.

James
I can supply, repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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Re: MS3 speedo output

Postby arran » Sun Oct 15, 2017 1:45 am

Thanks and thanks
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: MS3 speedo output

Postby arran » Sun Nov 19, 2017 2:12 pm

Is there any way to increase the frequency? 250Hz seems to be the fastest.

I can't find a PWM controlled motor that goes that low. 500Hz would get me out of trouble
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia


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