Speedo Output

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
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Buickv6
Posts: 12
Joined: Wed Jun 17, 2015 12:55 am

Speedo Output

Post by Buickv6 »

Lance,

I need some help with the Speedo Output (spare port 0). I am running a 4L60e gearbox with Mshift code 5101ii. I need the speed to be in km/hr. I have set the SI Lengths to be activated. In TunerStudio MS 2.6.19 the speed is shown in km/hr and the indicated mshift speed appears to be correct. I have checked this with GPS speed in TunerStudio and what mshift is indicating is very close to GPS speed and the speed gauge works smoothly with no sudden surging or dropping etc. So I assume that the VSS settings are o.k for mshift. The speedo output is working, although it appears to be indicating the speed in mph rather than km/hr. By this I mean that when I am travelling at 60 km/hr the speedo indicates just under 40 and at 100 km/hr it shows just over 60. The OEM computer sent 6250 pulses per km to the speedo and this is what I have set in the spare port 0 output settings. I have also tried 0,10,15,25,40,50,75,85,90,95 and 99 for the speedo output duty cycle %. These numbers did not appear to have real effect on the speed indicated by the vehicle speedo. Can you see anything that I have done wrong? Any help would be appreciated.

Thanks
Attachments
CurrentTune.msq
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Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Speedo Output

Post by Bernard Fife »

BuickV6,

I am sure you have spotted something I should have done a long time ago.

I suspect that in the INI I forgot to make the parameter dependent on the kph/mph setting. The MShift internal calculations are all done in mph. But it wasn't always this way. And when switching to all imperials units (with the INI handling any conversions) I overlooked the speedo output setting.

I will fix this and post a new INI shortly (for 5.101, 5.101iii, 5.102, and 5.102iv).

Thanks for spotting this and bringing it up!

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Speedo Output

Post by Bernard Fife »

BuickV6,

Here is the updated INI for 5.101ii:
GPIO_MShift_5101ii.ini
(292.36 KiB) Downloaded 246 times
It appears to work on my bench, but let me know if it doesn't work for you.

I will put the other INIs on the site ( http://www.msgpio.com/manuals/mshift/files/ini/ ) or in the appropriate threads shortly.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Buickv6
Posts: 12
Joined: Wed Jun 17, 2015 12:55 am

Re: Speedo Output

Post by Buickv6 »

Lance,

Thanks for doing that so quickly, will download new code and upload into mshift controller when I get home form work. It is 3.20 am, Monday morning and I am getting ready to go to work so I will let you know how it goes a little later on after I get home from work.

Cheers
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Speedo Output

Post by Bernard Fife »

BuickV6,

No problem, I just wish I had spotted this myself a long time ago and saved you the bother!

One thing you might notice is that your PPM setting might change when you load the new INI, and you might have to reset it. This is because the internal value will still be in pulse/mile but the numerical value will be reported as pulse/kilometer with a conversion value. So you might want to check that parameter after loading the new INI the first time (after that it should stay the same).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Buickv6
Posts: 12
Joined: Wed Jun 17, 2015 12:55 am

Re: Speedo Output

Post by Buickv6 »

Lance,

Have tried the new INI and my speedometer now shows in km/hr :D , once again thank you very much for sorting it out so quickly. I appreciate the support you provide for mshift users.

Cheers
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