Dual throttle on Tesla SDU

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catphish
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Dual throttle on Tesla SDU

Post by catphish »

Is the "brake sensor signal" line "pot2"? Can this be used for dual throttle inputs? My vehicle has no brake sensor, but it does have a dual throttle.
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cloudy
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Re: Dual throttle on Tesla SDU

Post by cloudy »

From Johannes' params video - it appears dual throttle acts differently than you would expect (ie: it's shown as additive, so if one throttle channel fails, the other continues) I would have expected any disparity in the "scaled" outputs should result in zero throttle as a safety measure, but that doesn't appear to be the case... I think it's called Dual Channel mode in the setup.
I think pot2 is generally otherwise used with a potentiometer just to adjust regen power.

There is some basic protection if your throttle goes above a preset max - but that's no good if your throttle goes to the full 5v in normal use!
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Re: Dual throttle on Tesla SDU

Post by johu »

Yes I changed behaviour to resort to the remaining channel because being stranded on the highway even though you could still drive doesn't seem that safe either
You should trigger a warning light though by observing “lasterr“ for example
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Re: Dual throttle on Tesla SDU

Post by cloudy »

I didn't realise that triggered an error condition - guess you could kick the inverter out by monitoring that over CAN if need be then...
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Re: Dual throttle on Tesla SDU

Post by catphish »

johu wrote: Sun May 29, 2022 9:08 pm Yes I changed behaviour to resort to the remaining channel because being stranded on the highway even though you could still drive doesn't seem that safe either
You should trigger a warning light though by observing “lasterr“ for example
If you can detect which input is the bad one and disable it, that's ideal, thanks!

Can I just re-ask my original question though? Is the brake input on the SDU board pot2? So can it be used for redundant throttle?
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Re: Dual throttle on Tesla SDU

Post by cloudy »

Yes, in the dual throttle mode pot2 is used as the redundant throttle....

potmode
0=Pot 1 is throttle and pot 2 is regen strength preset
1=Pot 2 is proportional to pot 1 (redundancy)
2=Throttle/regen controlled via CAN (like 0)
3=Throttle via CAN with redundancy (like 1)

I believe the digital "brake" input is separate, and ramps on a preset amount of regen.
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Re: Dual throttle on Tesla SDU

Post by catphish »

cloudy wrote: Sun May 29, 2022 9:38 pm Yes, in the dual throttle mode pot2 is used as the redundant throttle....

potmode
0=Pot 1 is throttle and pot 2 is regen strength preset
1=Pot 2 is proportional to pot 1 (redundancy)
2=Throttle/regen controlled via CAN (like 0)
3=Throttle via CAN with redundancy (like 1)

I believe the digital "brake" input is separate, and ramps on a preset amount of regen.
Thanks! It does seem very likely in that case that the analog brake input is pot2.

My intention is to connect the redundant throttle pots to the throttle and brake inputs, and of course connect the brake light switch to the digital brake input, if only to deactivate cruise control.
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