Brake pressure sensor on POT2.

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joromy
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Brake pressure sensor on POT2.

Post by joromy »

I have tried to put brake pressure sensor on the POT2 input.
But I wonder what is limiting this when input is max. (4095)
Is it brknompedal or brkmax?
Or do I get 100% regen when POT2 is 4095?
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Re: Brake pressure sensor on POT2.

Post by arber333 »

Whatever voltage you choose to put through.

Say you use analog brake pot 0 - 5K you get 0.5V - 4.7V signal from pedal. This is translated to 0.3V - 3.4V inside control brain.
If you only use digital ON - OFF you instantly get 5V signal so full range of AD converter (4095).

However if you use a "brake sw" input which is digital already together with a 5K pot inside cabin you can use this to adapt braking effect. I use this to reduce braking in winter.

brknompedal defines the braking torque that can be used with 100% regen signal. As i understand is dependent on minimal slip and function of V/Hz (rpm) of the motor.
brkmax defines regen torque when throttle is released and brake sw is not applied yet. It is given in % of brknompedal.
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Re: Brake pressure sensor on POT2.

Post by johu »

Well explained :)
Only thing: brkmax is % of max, it does not depend on brknompedal
All regen percentage values are in "percent of max V/Hz ratio" and always at minimal slip
When a pot is mounted on the brake pedal / pressure sensor it should operate "forward" i.e. increase value as you push pedal further.
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Re: Brake pressure sensor on POT2.

Post by arber333 »

johu wrote: Mon Jan 13, 2020 10:41 am Well explained :)
Only thing: brkmax is % of max, it does not depend on brknompedal
All regen percentage values are in "percent of max V/Hz ratio" and always at minimal slip
When a pot is mounted on the brake pedal / pressure sensor it should operate "forward" i.e. increase value as you push pedal further.
Hm... Which sensor has precedense? Is that throttle over regen?
So then i can use my 2nd sensor inside throttle pedal to pickup variable throttle position and map it to 0 point where i want to have it drive regen. That is awsome! There are still things i havent tried before...
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Re: Brake pressure sensor on POT2.

Post by chentron »

arber:
do You mean that you use in toyota throttle , 3 pins for throttle and 3 pins for the variable regen ?
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Re: Brake pressure sensor on POT2.

Post by Renegate2020 »

If you hang a 2.5K resistor on the "ECO" button - when you press it, the recovery will be 50%?
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Re: Brake pressure sensor on POT2.

Post by slociviccoupe »

Reading above replies, so way to get variable regen is either a potentiometer on brake pedal, use the second throttle sensor in the throttle pedal, or a multi position raoary switch with different resistances wired to the brake switch. In my case brake switch and cruise control decel switch wired in paralell so can force regen on switch without touching the brakes.
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Re: Brake pressure sensor on POT2.

Post by arber333 »

chentron wrote: Tue Feb 01, 2022 10:13 pm arber:
do You mean that you use in toyota throttle , 3 pins for throttle and 3 pins for the variable regen ?
Hm... i tried that and it didnt work right at the time. It would require some upside down calibrating of throttle2.

Currently i use 5k pot calibrated from 0.8V to 4.2V.
Lebowski can mix both throttles and can set different curves for both throttles. I set throttle1 as notmal throttle and then calibrate throttle2 from -0.3 to 0. This means when i release the actual throttle pedal i can get from 0 to 30% regen.
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