Pololu 18v7 POTENTIOMETER

Hi does anybody know how to setup the board to use RC to control the motor but use then use a connected potentiometer that is geared to tthe motor turns to control position i.e. stop the motor when the pot signals position reached.?

Hello.

It sounds like you are talking about one of our Simple Motor Controllers, which cannot do position control. For that, we recommend using one of our jrk motor controllers. The jrks can be configured to accept RC signals as inputs and use analog voltages, like those from the potentiometer that is geared to your motor’s output, as feedback to control the position of the motor. If you tell me more about your motor, like how much current it can draw at stall and what voltage you plan on supplying to it, I can help you choose which jrk is more appropriate for your system. (If you do not know how much current your motor draws, can you link to a datasheet or product page for it?)

-Jon

Hi Jonathan,

Many thanks for your swift reply.

I guess I guessed wrong when I picked the Simple Motor Controller however:-

I looked at the little video on your website for the Pololu Jrk 21v3 USB Motor Controller with Feedback (Fully Assembled) which looks to be ideal for my application.

Best Regards
George

Yes, the kind of control you described sounds like making your own custom multi-turn RC servo, which is possible with the jrk motor controllers. As for which jrk is more appropriate for your system, I noticed that you emailed me separately saying that you went ahead and ordered the jrk 21v3. While that jrk should be able to control your motor, you should be careful not to stall or heavily load the motor because it is capable of drawing more current than the 21v3 can handle. One way to help protect the jrk against large current draws is to configure its “Max. acceleration” and “Max. current” limits using the Jrk Configuration Utility. You can learn more about those two parameters under the “Motor Options” section of the jrk’s user’s guide, which you can find under the Resources tab of its product page.

-Jon

Thanks for the info Jon, I will experiment with the JRK 21V3 that I have bought and learn how to control it under no working load confitions (other than turning the gearing and the pot),. I would be grateful if you could tell me which model of the jrk series would be the one to use that could easily handle the max current that this motor can draw, bearing in mind that I will be using either a 5 off 1.2v rechargeable 2600ma AA CELLS in series (nominal 6V) battery lump or a 2 cell Lithium ION battery 1000ma 7.2v to drive it

~George

The jrk 12v12 can continuously handle the full stall current of that motor. However, the lower operating voltage of the jrk 12v12 is 6V, so it would be better to use your 2 cell lithium ion battery instead of your 6V rechargeable AA battery. You might also consider using a 6 or 7-cell rechargeable battery pack, which would have a more appropriate voltage for the 12v12.

By the way, it looks like you edited your post to remove the details of your motor. In general, we prefer not to remove content from a post, since it could be helpful for anyone else reading the thread that has a similar question or issue.

-Jon

I was about to change the motor spec because of the overload condition and didn’t want anyone to buy the wrong motor because of me.
However thinking about it now would be better to leave that blank and let them get advice from yourself about the correct spec of motor that is required.

~George