Help with Potentiometers

Hello, I have been asked to learn how to program with potentiometers in our lift. If somebody could please help me by explaining how to even start programming with these things I would REALLY appreciate it, one fellow robotics person to another. Thank you in advanced for your help.

Try this…

https://vexforum.com/t/scissor-lift-potentiometer-problem/27841/1&highlight=potentiometer

https://vexforum.com/showthread.php?p=370127#post370127

I recently answered a question similar to this. Just as a warning potentionmeters have been known to fail quite often and they can be very inaccurate so use with caution. Although they can be used quite effectively if programmed properly.

If you have some more problems I can help work them out if you need. I’ve been playing around with them on our robot for weeks now.

Best regards Amelia!

citation needed :slight_smile:

I’ve never had an issue with potentiometer accuracy, and the only time I’ve had one fail is when I shredded the wire (oops) or spun it beyond its range of motion.

I could have phrased it better sorry. I’ve had problems with potentiometers failing and having wild inaccuracy problems in the past. I’ve replaced 3 or so on my robot during the months which stopped functioning without any modifications to them.

Where do you use your potentiometers? Our team is currently using them on a Vex Clawbot remake.

Best Regards.

We have had this problem a few times, with “jumping” values. One thing that may help you is to mount the pots in a way that there is no bending force on the axle. Also replace any damaged ones, if they are still in warranty VEX should replace them.

To test them, we made a simple program that every 50 or so msec wrote to debug stream the value as we moved it. See the attachment to see some of the results we found with bad pots. (This was from last year, haven’t used them yet in our design this year) Sorry about the weird page splitting thing.
Faulty Pot #1 and #2.pdf (59.5 KB)

I believe this was the problem for us, also we had some old faulty potentiometers laying around that people forgot to get rid of. We have two axles lifting an arm and one axle had a small curve in it. We fixed it by pinched the two axles together with a neat little barring device.

Thanks for the valuable info!

Best Regards.