Tesla SDU Drive / Reverse Select Interlock

[DFDF]

Hello everyone,

I have been making some progress with a bench setup with a Tesla SDU that will hopefully get into the car soon. I have most things working well on the bench but the closer I feel I’m getting to install things in the car, the more questions come into my mind.

My latest question... I believe there should be some interlock so you can only select drive or reverse and even move out of one or the other back to neutral when you have your foot on the brake pedal.

I’m still up on the bench right now so the brake swich is not connected but I can’t see that that would do anything to help here. It seems this is more about regen, cancelling cruise control and disabling the throttle when the brake is pressed. At present it’s not connected so if this were to have some control there, I think that it shouldn’t be working as I can select drive and reverse on the bench as things are. Though I do note I can’t change direction whilst the motor is spinning.

I was thinking maybe an Arduino or something similar driving some relay(s) to make the gear selection. Where I can check the conditions, sequences etc before outputs are performed. Of course, I will have to divide the 12V inputs down to 5V and the reverse with the outputs to make this sort of idea work. But it seems possible. But before I go down that road I was wondering if I have missed something. Am I overcomplicating things. I didn’t know if anyone would share what they have done here?

Thank you in advance for any pointers or ideas.

[Bratitude]

Hello everyone,


My latest question... I believe there should be some interlock so you can only select drive or reverse and even move out of one or the other back to neutral when you have your foot on the brake pedal.

I’m still up on the bench right now so the brake swich is not connected but I can’t see that that would do anything to help here. It seems this is more about regen, cancelling cruise control and disabling the throttle when the brake is pressed. At present it’s not connected so if this were to have some control there, I think that it shouldn’t be working as I can select drive and reverse on the bench as things are. Though I do note I can’t change direction whilst the motor is spinning.

I was thinking maybe an Arduino or something similar driving some relay(s) to make the gear selection. Where I can check the conditions, sequences etc before outputs are performed. Of course, I will have to divide the 12V inputs down to 5V and the reverse with the outputs to make this sort of idea work. But it seems possible. But before I go down that road I was wondering if I have missed something. Am I overcomplicating things. I didn’t know if anyone would share what they have done here?

Thank you in advance for any pointers or ideas.

There is a series of safety features built in, but what your describing is not an issue if the resolver offsets are set properly.

There is a variety of settings regarding brake on start up, and drive lock out on throttle, etc.

Setting up some switches state logic with some relays just sounds like a lot of additional failure points and is over complicating things.

[catphish]

Some of the features you're describing exist in the openinverter software and some don't. From memory:

* Pressing the brake pedal disables cruise control and disables the throttle.
* Gear selection does not require the brake to be pressed and this is not an option that currently exists.

If you want the latter feature then it would be best to implement it in the software. I don't think this would be very challenging, as there is already code to block gear selection above a selected speed. Doing it this way would be much more useful and configurable. I don't think this has been deemed necessary in the past, but it does seem like a reasonable addition.

[DFDF]

Great, thank you for your help.

[muehlpower]

What is the current behavior of the latest software version? For example, what happens if potmode is set to “0=Pot 1 is throttle and pot 2 is regen strength preset” and pot1 and pot2 both have a positive value? Can the vehicle be started without a brake signal and the throttle remain active, even with the brake light signal?

Specifically, I want:
Start only when the brake is applied
Cruise control off when the brake is applied
Gears can be selected without applying the brakes
Throttle signal takes priority over recuperation
Throttle signal not switched off by the brake signal

Can this be configured?

[johu]

Start only when the brake is applied

with cruise control enabled there is a brake check

Cruise control off when the brake is applied

yes, always

Gears can be selected without applying the brakes

yes

Throttle signal takes priority over recuperation

same pedal, so not physically possible to have regen and accel at the same time. Second input only sets a preset for max regen, it is not a regen command.

Throttle signal not switched off by the brake signal

Not currently possible

[johu]

Moved to Tesla forum. Please put some thought into choosing a matching forum