Help with steering pot setup

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Canyonfive
Posts: 69
Joined: Mon Jan 29, 2018 11:20 pm

Help with steering pot setup

Post by Canyonfive »

Hello, I have a steering pot that varies in resistance from .8 to 1.7 ohms.

Ground to ground
5v to ref voltage
Pickup to analogue input 1.

It always reads 5 volts. Do I need a pullup resistor? Or have I messed up somewhere?

A

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi,

Putting aside the sensor for the moment, try this:

* Set your analog input channel to 'Raw' voltage
* write the config
* Go to the dashboard to monitor the value
* Connect the analog 1 wire to ground. Does it show 0v?
* Now connect analog 1 wire to 5v reference. Does it show close to 5v?

if so, then you're reading the data correctly from the port.

Try double checking the connections to the steering pot and verifying that you have the center wire connected to the analog input.

Let us know how it works out.
Brent Picasso
CEO and Founder, Autosport Labs
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bbundy
Posts: 1
Joined: Sun May 27, 2018 7:13 pm

Post by bbundy »

Im having the same problem. It is a AIM rotary steering pot. hooked to analog input2

Race capture just reads 5 volts. I put a volt meter in between the analog input wire and ground and it reads 2.6 volts goes up when I turn one way down when I turn the other.

Then I discovered the Race capture was reading correctly only when the volt meter was connected in the circuit as soon as I take the volt meter out of the circuit the race capture goes back to reading 5 volts.

Whats going on here? grounds all check out fine.

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

RaceCapture has very high input impedance, and if the analog connection is not connected, then it will 'float' and show a voltage.

Setting aside your sensor, try this:

Set your mapping type to "raw"
Connect your analog input (say, Analog1) to Ground. RaceCapture should show close to 0v.
Connect your analog input to the 5v reference. RaceCapture should show close to 5v.

If you connect a potentiometer (variable resistor), you can connect the center tap of the variable resistor to the analog input, and then the side taps to gnd and 5v, respectively. Then, you should see the input vary as you turn the knob.

Hope this helps; Let us know what you find out!
Brent Picasso
CEO and Founder, Autosport Labs
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l8apex
Posts: 5
Joined: Sat Mar 07, 2020 4:05 pm

Post by l8apex »

Sorry for resurrection...

I'm have a similar issue with my setup. However, I don't see just 5v; I see a very short voltage range. Fully retracted it's reading 4.63v and fully extended it's reading 5.01v. I've mapped it out to 5 points (left to right: -360, -180, 0, 180,360) but RaceCapture seems to be "chaotic" with it's display for the readings. With the wheel stationary the readings can't seem to settle on a number.

I'm using a Celesco SP1-12 pot and it's wired properly into a SensorX and then into RaceCapturePro.

Within RCP I've tested the smoothing feature for the sensor but that just seems to slow the changes a bit.

Is there anything that can be done to expand the range that might help? I thought maybe a resistor in the 5v Ref line but not sure that'd work.

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi - You're using only a tiny bit of the allowable 0-5v range; that's why you're seeing so much jitter.

At one end of the range it should read close to 0, at the other, it should be close to 5v.

As a test, you might want to connect a simple potentiometer and simulate the full range. We recommend proving that it works with a simple potentiometer, and then work backwards from there.

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