Question 360° hall effect potentiometer and SMC3

I searched everywhere in the forum, but I must not be smart, I can't find the answer to the following question:

I have hall effect potentiometers at 360, but under SMC3 when my potentiometer reaches its highest level it switches to low (I understand that it is in fact a voltage tap +- 5 volt or 2 ,5...), I would like to make SMC3 understand that I have a 360° potentiometer and not 180!

Is there a parameter in the arduino code (pot scaling????) that allows me to manage this problem.

The chair itself works well, but when I stop the power my chair gets up and puts my potentiometers at the maximum height travel, I therefore exceed the limit value in SMC3, and if I restart the power, suddenly my motor goes in the opposite direction to what it should operate.

I therefore always have to help my wheelchair when starting to lower it while it starts, and I would therefore like to avoid this by having potentiometers that operate at 360°...

I think this is just an offset problem. The 360° sensor has no stop so it rolls over to 0° if it goes above 360°.

Make sure the center position is correct. Move your arm to the neutral position (with the motor power off). Loosen the set screw of the coupling (or take the belt off) and turn the potentiometer until the output is 2.5V. Then tighten the set screw (or put the belt back on).

I've already done that, and the chair normally works very well.

The problem is that if I make my lever arm do a 360 degree, under SMC3, the rocker of the potentiometer line jumps, as soon as it reaches the top (roughly 90 degrees at the top), it jumps down to start again.

Under SMC3 basically I have a coding which corresponds to a 180° not a 360, it is not sinusoidal when it reaches the stop at the top, it leaves from the bottom!?......

If I stay in the range without going to the high or low end, my potentiometer works very well, and the signal is indeed sinusoidal.

So I suspect a modification has been made to the SMC3 code, for example I have not validated the linear or non-linear pot option... but I tested and it seems to be the same....

I think I understood why I can't have the entire range of my potentiometers under SMC3...

My hal effect potentiometers are 360° with a range of 12 bits... SMC3 manages 10 bits.

And secondly SMC3 was designed not to exceed a certain limit (therefore designed to only manage 180° max!).

Apart from re-writing an SMC3, I would need to find another software that manages the 360 rotation of a motor and its control... if anyone knows of software that manages this?

<a href="https://zupimages.net/viewer.php?id=24/48/wnke.jpg"><img src="https://zupimages.net/up/24/48/wnke.jpg" alt="" /></a>

<a href="https://zupimages.net/viewer.php?id=24/48/wnke.jpg"><img src="https://zupimages.net/up/24/48/wnke.jpg" alt="" /></a>


When the chair is stationary (angle of more than 180°...)

and when he works, normal angle...

As soon as I start, as it can't find the right data from the potentiometers it tilts the arm to the left when it should go to the right... that's mainly my problem, I have to lower it with the arm on the right side before starting the arduino card........

My original construction allows 360° rotation without breaking anything, I always think about the bug that could happen, hence the possibility for my chair to have motors that run in circles without problems (apart from the torque !!!)

Below are pictures of a properly set motor arm, in addition, in your case you have more teeth in the pinion on the motor than on the potentiometer which has already been described on the forum that sometimes causes errors , you need to limit the swing of the motor arm max to +45 degrees / -45 degrees from the initial position ( motor arm horizontal to the base ). I printed myself the 86 tooth gears for the motor shaft and the hall sensor shaft so I have a ratio of 1:1. I can provide you with .stl files to print.

Initial position


Max UP


Max DOWN

Ok I just understood about the number of teeth!!

I suspected something like that..... but I honestly thought that SMC could receive the 360° of the potentiometer....

I'm interested in STL files and thank you for taking the time to show me and explain.

Attila.pl as found the solution at my problem. And yes my motor can be rotated.

The gears fit quite tightly, they may require some gentle filing to push them onto the axle properly

I can't see all the pictures but from the one in post #5 my guess is that the gear ratio from the motor aoutput shaft to the hall sensor/potentiometer is more than 2:1. So when your actuator arm rotates 180° the sensor rotates >360° which causes the roll over in the false direction.

As @Attyla.pl already said, you need to limit your range to less than 180°.