I am using a Micro Maestro, powered by a powered USB hub. It is controlling a servo that is moving quite a bit when I shutdown the PC, that is controlling the Maestro. I have set the movement limits but the servo moves past them on shutdown. Any suggestions on what I can do to fix this issue would be greatly appreciated.
Hello.
Just to clarify, are you saying that the servo is moving beyond the limits set in the “Channel Settings” tab of the Maestro Control Center? If so, then I suspect the erratic behavior is just from your servo losing power (and not something the Maestro is sending). Depending on your servo, it might help to stop sending pulses before powering down your PC. You can command a Maestro channel to stop sending pulses by disabling the channel, which you can do from the “Status” tab of the Maestro Control Center or by sending a target position command of 0.
If that doesn’t help, can you post more details about your setup, such as what are you using for servo power and if that is being removed at the same time the PC is shutdown? Also, how are you controlling the Maestro? A video demonstrating the problem might be helpful as well. The forum does not allow users to post very large videos, but it does work well with videos linked from other sites (like YouTube or Vimeo), or you could share a link to a cloud folder with the video (e.g. a Google Drive or Dropbox folder).
Brandon
The servo is getting power from a powered USB hub. The hub is being controlled by a pc , so when the PC shuts down, the hub shuts down. The servo is turning a micro switch on and off. The servo was moving past the switch’s lever when it was moving on PC shutdown. On PC power up, the servo would try to move to it’s correct position, but then would get caught on the micro switch’s lever. I was able to get around this issue by using a switch with a longer lever and bending it in such a way so the servo would not get caught on it.
Have you tried turning off the servo signals before shutting down like I suggested previously? Some digital servos will continue holding their last known position when they stop receiving valid signals, others will stop holding. If yours stops holding its position, removing the signal before power might help.
By the way, it might be okay to power your servo like that depending on your particular servo and powered USB hub, but please note that USB-A ports are typically only intended for 500mA of current, and we typically recommend budgeting at least 1A per standard size servo.
Brandon