Anyone know how to make an automatic transmission?

[LazerRay]

This has been driving me crazy trying to have vehicles automatically shift gears while driving, I did find one environment car that has this feature the "Jeepie_mk3", sadly there is no way to use this in build mode to see how it was set up.

I'm hoping the original creator of the Jeepie_mk3 can share their secret on auto-shifting or someone else knows how to do it, since transmissions are manual by default (Yet they used to be automatic by default in HB13 and below).

[Igniuss~]

Originally posted by LazerRay:

This has been driving me crazy trying to have vehicles automatically shift gears while driving, I did find one environment car that has this feature the "Jeepie_mk3", sadly there is no way to use this in build mode to see how it was set up.

I'm hoping the original creator of the Jeepie_mk3 can share their secret on auto-shifting or someone else knows how to do it, since transmissions are manual by default (Yet they used to be automatic by default in HB13 and below).

There are a couple ways you could set this up, either by the current RPM output and some logic, or the current speed. There are a ton of ways you can set this all up though!
I suggest checking out Nailguns thread in Tutorials and tips, he explains his system in full detail!

[LazerRay]

I saw that thread after I posted this one, was hoping for an RPM based system since that is what I think the Jeep is using, a speed based version might be problematic for my total rebuild of one of my old vehicles that I made in older versions of Homebrew (If you remember the Explorer from the old forums)

[Igniuss~]

Originally posted by LazerRay:

I saw that thread after I posted this one, was hoping for an RPM based system since that is what I think the Jeep is using, a speed based version might be problematic for my total rebuild of one of my old vehicles that I made in older versions of Homebrew (If you remember the Explorer from the old forums)

It's basically the same principle for RPM, just gotta use the RPM output instead of speedometre :D And a lot of redoing to get the values just how you want them :P

[LazerRay]

I saved the image and text for offline use so I can experiment later.

I will have to come up with my own system to have automatic reverse once the forward gears are working.

[Nailgun]

Originally posted by LazerRay:

I saw that thread after I posted this one, was hoping for an RPM based system since that is what I think the Jeep is using, a speed based version might be problematic for my total rebuild of one of my old vehicles that I made in older versions of Homebrew (If you remember the Explorer from the old forums)

I've made some versions using RPM but there were a few issues with that, mainly that since it's so easy to spin tires, it will just shift up while you spin the tires. A real auto (at least older ones) would definitely do that if you stand on a patch of ice and floor the throttle, it would also eventually blow up. Another thing that's a bit tricky is the RPM values can change very quickly making the whole logic circuit go in a semi-feedback mode meaning it can shift up/down constantly when you spin the tire, auto shifts, regain traction but rpm drops making the auto downshift again, spin the tires, auto upshifts, repeatedly. You'll have to add some logic boxes to either smooth it out (which will increase the shift time..) or you can use either road speed and/or throttle position to prevent an upshift/downshift in those cases.

[King Shibby]

Yeah Nailgun, I'm still using combo RPM + speed thresholds for that reason. Works very nicely. I use your simple formulas for calculating the appropriate RPM for a given speed which also lets me do some sort of (very simple) traction control to prevent burnouts.

[LazerRay]

I couldn't figure out how to set up an RPM based automatic, so for now I'm just using the speed based version from the tutorial, I did discover an interesting side effect with it though. If you disconnect the manual inputs you wind up with a reverse gear toggle with the set up from the tutorial.

[Nailgun]

Originally posted by LazerRay:

I couldn't figure out how to set up an RPM based automatic, so for now I'm just using the speed based version from the tutorial, I did discover an interesting side effect with it though. If you disconnect the manual inputs you wind up with a reverse gear toggle with the set up from the tutorial.

Well you can start by reading this post in the Automatic Transmission thread a made:
http://steamcommunity.com/app/325420/discussions/5/350542683189144706/?ctp=2#c350542683196496911
Understanding this can help in figuring out the best way to implement it.

The simple approach would be to connect a modify to the engine RPM output and set the offset as a negative of the rpm you want to upshift at. So you want to upshift at 2900RPM, use an offset of -2899. When the input is 2900, the modify outputs 1, use that 1 as your upshift impulse. You can do a similar layout for the downshift point. It quickly becomes tedious at that point, at least for me, because you need 1-to have a transistor pulsing on/off, checking if the gear needs changing for the circuit to keep working and 2-depending if you use setgear or gear up/down, you needs to have limits to prevent a downshift into reverse, and some form of smoothing to keep the whole thing stable. I haven't found an elegant layout yet. Here's an example of what i've tried (no smoothbox..):

http://steamcommunity.com/sharedfiles/filedetails/?id=800075201

[LazerRay]

I actually saved your instructions on the speed based transmission to use in offline mode and it has been working for now (Its just tedious to reset the modify boxes any time I change the gear ratios).

Following the tutorial is how i discovered the reverse gear toggle after disconnecting the manual inputs.

[Nailgun]

Originally posted by LazerRay:

I actually saved your instructions on the speed based transmission to use in offline mode and it has been working for now (Its just tedious to reset the modify boxes any time I change the gear ratios).

Following the tutorial is how i discovered the reverse gear toggle after disconnecting the manual inputs.

Yes that's the main annoyance but once your vehicle is 'done' you aren't constantly changing ratios so in the end it works very well, just annoying if you implement it before finalizing other stuff first.