Servo movement on power up

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michaelr87
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Servo movement on power up

Postby michaelr87 » Tue Jan 24, 2012 10:35 am

I am working with a team building a flight simulator and we are planning to use the AdvancedServo 8-motor controller (1061) and several servo motors to run a number of gauges in the cockpit. However, due to the design of the gauge we cannot have the servo overshooting the desired position or it will sweep the needle into the case of the gauge. I can keep the servo in the desired range during use, but does anyone know if it is possible to stop the servo from moving when it is first powered up? Thanks in advance for any input.

Michael

erik
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Re: Servo movement on power up

Postby erik » Tue Jan 24, 2012 11:00 am

You can set the servo to the desired position before enabling and powering up the servo. This will allow the servo to always move to the known position when started.

Otherwise, you will have to save the last position of the servo before powering it down and then set that to the target position before enabling it.

michaelr87
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Re: Servo movement on power up

Postby michaelr87 » Tue Jan 24, 2012 11:18 am

I understand what you are saying, but that isn't exactly the problem. It isn't moving when enabling, it is moving as soon as the USB cable is plugged in (or computer is powered on), without any controlling software running. Sorry for not being clear in my first post.

Michael

Jacob
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Re: Servo movement on power up

Postby Jacob » Thu Feb 02, 2012 9:27 am

They should always initialize to the same position (the center on most servos). If the problem is that the needle swings into the case, angle the needle so that when the servo is in the center, it doesn't hit the case, and adjust your code accordingly.

michaelr87
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Re: Servo movement on power up

Postby michaelr87 » Thu Feb 02, 2012 10:24 am

Then we must have got a faulty servo motor, because this one will move every time it is connected and if you connect and disconnect it the servo will ultimately do complete circles, it never settles on it's zero position.

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Patrick
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Re: Servo movement on power up

Postby Patrick » Thu Feb 02, 2012 11:15 am

Hi,

We have tracked this down to a firmware bug on 1061. You are welcome to contact support@phidgets.com about getting your firmware upgraded/swapping for a replacement.

You may find that the effect is less severe on some of the servo channels - but it definitely affects all channels to some extent.

-Patrick


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