Controlling servos with pot doesn't work

I'm able to control the servo with a potentiometer perfectly fine when the servo is using the power from the arduino. but when i hook up the servo to a 6v power supply it just stops working. I'm using a HS-645MG Ultra Torque Servo.

You need grounds to be commoned.

MarkT: You need grounds to be commoned.

That doesn't seem to be fixing my problem.

Also is it possible to break a servo if you connect the ground to the positive and vice versa?

superhb: That doesn't seem to be fixing my problem. Also is it possible to break a servo if you connect the ground to the positive and vice versa?

Yes. Did you do that?

OldSteve:
Yes. Did you do that?

I think i might have. Im using wires that were the same color and i probably got them mixed up and plugged it in like that…

superhb: I think i might have. Im using wires that were the same color and i probably got them mixed up and plugged it in like that...

All you can do is connect it up taking power from the Arduino again, (last known good configuration), then cross your fingers and test it. If it doesn't work, your servo has gone to servo heaven, Hopefully the problem is something else.

OldSteve:
All you can do is connect it up taking power from the Arduino again, (last known good configuration), then cross your fingers and test it.
If it doesn’t work, your servo has gone to servo heaven, Hopefully the problem is something else.

Well… It’s broken… I still need help with this problem while I order a new servo…

superhb: Well... It's broken... I still need help with this problem while I order a new servo...

What problem? I was assuming it didn't work on 6V because you connected it backwards and killed it.

Do you mean that when connected properly, and before it was connected backwards, it still wouldn't work on 6V? Are you sure it was connected properly for that test?

I make a habit of always using colour-coded wires, with red for +V, black for 0V, and various colours for signals. Besides helping to avoid connecting things up improperly, it helps for tracing connections when troubleshooting.

OldSteve: What problem? I was assuming it didn't work on 6V because you connected it backwards and killed it.

Do you mean that when connected properly, and before it was connected backwards, it still wouldn't work on 6V? Are you sure it was connected properly for that test?

I make a habit of always using colour-coded wires, with red for +V, black for 0V, and various colours for signals. Besides helping to avoid connecting things up improperly, it helps for tracing connections when troubleshooting.

Im talking about the original problem I made this post for. I can't get the potentiometer to control the servo when the servo is on a separate power supply. I got a reply earlier saying the grounds need to be common but I don't know if I did that correctly.

superhb:
Im talking about the original problem I made this post for. I can’t get the potentiometer to control the servo when the servo is on a separate power supply. I got a reply earlier saying the grounds need to be common but I don’t know if I did that correctly.

Right. I just automatically assumed that the reason it didn’t work on a 6V supply was because you’d fried it in the process of connecting to 6V.

I guess you can’t test it now until your replacement servo arrives, but to run the servo on 6V, controlled by the Arduino on a separate supply, the connections need to be as shown on the diagram I just drew up, (attached below).

Servo Arduino & 6V Supply.JPG

OldSteve: Right. I just automatically assumed that the reason it didn't work on a 6V supply was because you'd fried it in the process of connecting to 6V.

I guess you can't test it now until your replacement servo arrives, but to run the servo on 6V, controlled by the Arduino on a separate supply, the connections need to be as shown on the diagram I just drew up, (attached below).

I have a lot other servos to test with. That did get it to work for me. Thank you.

superhb: I have a lot other servos to test with. That did get it to work for me. Thank you.

Oh good. Glad I could help, but MarkT deserves most of the credit for realising what the problem might have been.

At least you're back in business, and learned something along the way. :D