# Open Revolt Throttle 'Pot'.



## jackbauer (Jan 12, 2008)

Hi Adam the default input for the revolt is a 0-5k pot. However I have made modifications for use with a BMW hall effect pedal. As a result it can use any hall effect pedal in the 0-5v range.


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## Ace_bridger (Nov 22, 2011)

Cheers Jack,

Is it a tricky mod? Hall effect is very mych my prefered route.

When you say 0-5K pot do you mean a 0-5K variable resistor?


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## jackbauer (Jan 12, 2008)

A potentiometer will act as a variable resistor if you wire the wiper to either side terminal. its not difficult to use a hall sensor pedal. Just requires 2 resistor changes (one is linked out and the other removed) and different software in the micro. Have a look at the pics here:
http://ecomodder.com/forum/236391-post4775.html

and you will see R10 removed and the one with the scope ground linked out. Just a case of feeding the hall sensor with 5v and ground and feed the signal into the throttle input pin of the micro via the 4k7. Easier to do then to describe I have the modded firmware if you decide to go this route.


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## Ace_bridger (Nov 22, 2011)

That's good news, I'll plan to do that.

We design and make F1 hall effect throttle sensors at work so I can bag a freebee and get the guys to make me an assembly mechanism to mount it on.

I wonder if people would be interested in buying these sorts of things?

Thanks again.


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## Ace_bridger (Nov 22, 2011)

PS. I wouldn't use a pot as a variable resistor in automotive applications. They are fundamentally different in their build. The contact pressure is very low on a pot and whereas they do have multiple fingers you can still get debris under which sends the R way high which could have less than ideal effects!!! Suddenly your full throttle..aaggghhhhhhH!!!!!!!!

Also the contact resistance will vary so you won't get quite as good an output as you would with a variable resistor.


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## jackbauer (Jan 12, 2008)

I think there would be a lot of interest in a throttle pedal with F1 spec! I actually used the old throttle body and tps from the bmw when starting out. Worked ok but didnt like the feel. Went with an e46 hall pedal assembly. Works great.


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## Ace_bridger (Nov 22, 2011)

Once I've got a successful working design I'll put details on here...


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## Ace_bridger (Nov 22, 2011)

Hi Jack,

I'm bench testing my controller and have the same software in the micro as is in yours. I'm getting high throttle lock-out fault.

Do you, by chance, know what threshhold voltages the software uses for zero throttle and full throttle?

I don't think it's 0-5V...something like 0.5-4.5V?

Any clues would greatly assist my bench tests. Paul is sending over a programmer but before it gets here I'd like to get it running on the bench by simulating your hall TPS output.

Cheers,

Adam


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## jackbauer (Jan 12, 2008)

It should be programmable via rtd explorer. i think its something like t-fault-rc or something like that.


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## Ace_bridger (Nov 22, 2011)

Sorry, I meant could you let me know what your TPS puts out. My code is the same as yours, and neither Paul nor I can't access it at present, and I'd like to give the software what it needs such that I can get the controller going on the bench. Paul is sending the kit I need to reprogram the chip.

It's something like 0.5-4.5V...if you can't remember of the top of your head don't worry...I can wait until the stuff arrives from Paul.

My chip doesn't have a bootloader on so I can't program the chip...apparently, so Paul says, all Greek to me!! 

Cheers,

Adam


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## jackbauer (Jan 12, 2008)

Adam , i think its something like 0.7 to 4.2v I might mention it on one of the videos can't remember , sorry


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## Ace_bridger (Nov 22, 2011)

No worries, I'll do a bit of trialing around the 0.7V mark and see what happens.

BMW still going well?


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## Ace_bridger (Nov 22, 2011)

I got the controller to stop showing the flashing LED (error) when I gave it 0.6V when I powered it up.

So it looks like 0.6V for zero throttle.

I haven't figured out what the maximum throttle setting is yet. Hopefully I'll be able to get access to the settings when the kit comes in the post from Paul.

Just wanted to record the 0.6V here should others need it one day.


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## madmike8 (Jun 16, 2011)

I'm interested in doing this with my O-Revolt build. So keep the details coming, and Thanks!


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## Ace_bridger (Nov 22, 2011)

Hi Mike,

The mod was supplied from JackBauer and is straight forward. I think I have attached details of the mod.

The board changes are pretty simple and I can supply photos of mine if you'd like.

Paul supplied my controller kit with the software that Jack used and I'm just trying to match the input up to the software. I'll get there and will post all info here.

Cheers,

Adam


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## madmike8 (Jun 16, 2011)

Thanks Adam and Jack.


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## Ace_bridger (Nov 22, 2011)

I've had some success with finding the correct parameters for the hall effect throttle input on my controller...with help form Paul!!

"Anything below 0.5v should be an error, and 0.8v is considered zero throttle (anything below 0.8v and above 0.5v is zero throttle). And anything above 4.1v is full throttle, as long as it's less than 4.5v. So, I would set the pedal to 0.65v for zero throttle and 4.1v for full throttle." Thanks Paul!!

"Hi Paul,

I got connected to the controller and accessed the settings. They are attached. Could you have a look at the numbers and see if you agree with how I have converted bits to equivalent volts, please?

I’ve assumed that 5V is equivalent to 1023 bits so,

tminRC – 0164 bits is equivalent to 0.8V
tmaxRC – 0839 bits is equivalent to 4.1V
tfaultminRC – 0102 bits is equivalent to 0.5V
tfaultmaxRC – 0922 bits is equivalent to 4.5V

Does that make sense or am I way off?

Cheers,

Adam"


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## jackbauer (Jan 12, 2008)

I forgot to mention that I have a dead zone programmed in that code if memory serves so the throttle needs a little tip before bringing on the power if that makes sense.


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## Ace_bridger (Nov 22, 2011)

jackbauer said:


> I forgot to mention that I have a dead zone programmed in that code if memory serves so the throttle needs a little tip before bringing on the power if that makes sense.


What, you just blip the throttle before moving off to wake it up?

Thanks for all the help with this JB!! I'll be up and running soon and hopefully Mora will follow suit with his Golf soon aswell!!


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## jackbauer (Jan 12, 2008)

No its just that the first say 2mm of travel on the pedal have no effect on power. Its just the way I like it i guess and it leaves a safety margin so that if the hall sensor voltage flicked about a little it wont command power from the motor. Glad to help


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## Ace_bridger (Nov 22, 2011)

Agh OK, makes sense. I'll do some bech tests with my TPS once it's been made.


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