interesting servo actions

[tilky]

we installed the servo on a practice robot, and tried to run code. The y axis wasn't moving at all so I assumed it was my code. So I open the Servo example vi and run it. I get the same problem. What the problem is: When I run it normally, only the x works. We thought that the y axis servo is bad. So to verify this we switched the two pwm's. Now only the y axis works (changing the x value on front panel, but it affects the y axis on the physical servo). So for whatever reason that I can't figure out for the life of me, whatever value the computer sees at y axis doesn't work, which doesn't make any sense since you would set the x and the y axis values the exact same way

[Alan Anderson]

Can you be more specific about what part you're talking about? The servos with which I am familiar don't have an X and a Y axis. They have a single output shaft that rotates through approximately 200 degrees of travel, give or take.

[tilky]

I thought all servos are like this, but there is a single motor for tilt, and another one for pan. sorry for the terminology errors, but I was referring the the pan as the x axis and the tilt as the y axis. I'm pretty sure the example program on labview calls it this also.

[Greg McKaskle]

You are referring to a pan/tilt assembly using two servos, sometimes called a gimbal.

Before enabling vision, move the sliders and determine if the servos work and if they are on the correct ports. Remember that you need a jumper next to the Digital Sidecar PWM for each.

Once you have working servos, you can enable vision, calibrate the color, and have the camera track the colored target.

Please indicate where the failure is again?

Greg McKaskle

[tilky]

whenever I try to set the y value, on whatever PWM, it doesn't set it (tilt). But if I switch the PWM's manually to see if the tilt servo is working, only that one works and the pan doesn't. So whatever one is supposed to be the y doesn't work

[RufflesRidge]

Check that both ports have the Jumper installed correctly. You can also try changing the port for the "y" servo to verify it isn't an issue with that one specific port on the Digital Sidecar.

[tilky]

I did and I thought I said that I did

[RufflesRidge]

Originally Posted by tilky

I did and I thought I said that I did

And? What was the result? Does the issue stay with the port (PWM 9 for example?) or does it follow the code?

If you, in software, change the Y to be on the currently working 'x' port does it work? If not, the problem is in code; if so, then the problem is either in the Digital Sidecar or your DB37 cable to the Digital Sidecar, it is possible to reconstruct the cable in a way that not all pins fully make contact.

[tilky]

I left the code the way it was when only pan worked and switched the two PWM wires. Then only the tilt worked. is it at all possible that it is code or should I get the electrical team

[RufflesRidge]

Originally Posted by tilky

I left the code the way it was when only pan worked and switched the two PWM wires. Then only the tilt worked

Which is great, that rules out an issue with the PWM cable and the servo. You still have the code, Digital Sidecar and DB37 cable left to troubleshoot which is where my suggestions differ from what you have already tried.

[tilky]

Originally Posted by Mike AA

You may just have a bad cable. Check the cables with a continuity tester.

can you please read all of the posts before you reply. We already ruled that out numerous times

[tilky]

to troubleshoot sidecar, run drive motors on the pwms I was using???

[RufflesRidge]

That would work, or the 'x' servo code that you know is working properly. Any code that you know 100% is correct and you can just change the PWM port to try to test the DB37/Digital Sidecar. To narrow it down between those two you would have to swap one of them out or test the continuity of each pin of the DB37 as MikeAA suggested above.

[tilky]

I think drive would be the most logical. Will test