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Is this a misbehavior?

Prasad
 

This morning I had my OnStep controlled Vixen GP mount out on the deck and I was observing the sun. Since I had not done any polar alignment sun was drifting. So I had to, sometimes, push a direction button on my phone that runs the OnStep app to bring sun back to the center. Everything was fine until about 2 hours into the session when I noticed the misbehavior. When I make a quick/short push on North button my scope would go the other way. Push the same button again then it went the right way. A third push would make it go the wrong direction and back in the right direction for the next push. I think I had experienced this behavior once before but I ignored it blaming it on an operator error. 

I did a power reset and all was fine after that. I wonder what was the cause? 

Prasad

Dave Schwartz
 

This is typical (expected) behaviour if OnStep thinks you are close to a celestial pole... the direction of north keeps changing if your last north slew passed through a closest approach to the pole.

If you did not do any sort of alignment then who knows where it thought you were pointing when you turned it on and moved to the sun. When you turned it off, the model would have been reset and your perceived issue would have not appeared.


On November 3, 2019 1:31:37 PM EST, "Prasad via Groups.Io" <ad_prasad@...> wrote:
This morning I had my OnStep controlled Vixen GP mount out on the deck and I was observing the sun. Since I had not done any polar alignment sun was drifting. So I had to, sometimes, push a direction button on my phone that runs the OnStep app to bring sun back to the center. Everything was fine until about 2 hours into the session when I noticed the misbehavior. When I make a quick/short push on North button my scope would go the other way. Push the same button again then it went the right way. A third push would make it go the wrong direction and back in the right direction for the next push. I think I had experienced this behavior once before but I ignored it blaming it on an operator error. 

I did a power reset and all was fine after that. I wonder what was the cause? 

Prasad

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Prasad
 

That's odd because I live at 40 degree latitude, near Philadelphia PA. I must try again and see if I missed something. 

Thanks
Prasad

On Sunday, November 3, 2019, 04:02:39 PM EST, Dave Schwartz <dave.schwartz@...> wrote:


This is typical (expected) behaviour if OnStep thinks you are close to a celestial pole... the direction of north keeps changing if your last north slew passed through a closest approach to the pole.

If you did not do any sort of alignment then who knows where it thought you were pointing when you turned it on and moved to the sun. When you turned it off, the model would have been reset and your perceived issue would have not appeared.

On November 3, 2019 1:31:37 PM EST, "Prasad via Groups.Io" <ad_prasad@...> wrote:
This morning I had my OnStep controlled Vixen GP mount out on the deck and I was observing the sun. Since I had not done any polar alignment sun was drifting. So I had to, sometimes, push a direction button on my phone that runs the OnStep app to bring sun back to the center. Everything was fine until about 2 hours into the session when I noticed the misbehavior. When I make a quick/short push on North button my scope would go the other way. Push the same button again then it went the right way. A third push would make it go the wrong direction and back in the right direction for the next push. I think I had experienced this behavior once before but I ignored it blaming it on an operator error. 

I did a power reset and all was fine after that. I wonder what was the cause? 

Prasad

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Dave Schwartz
 

Did you set up the mount in approximately the home position, move it manually to the sun and then power on and enable tracking? If so, it would have thought you were pointed at the pole and you would have seen this behaviour. First question in the FAQ https://onstep.groups.io/g/main/wiki/Frequently-Asked-Questions-%28FAQ%29.

On 2019-11-03 5:03 p.m., Prasad via Groups.Io wrote:
That's odd because I live at 40 degree latitude, near Philadelphia PA. I must try again and see if I missed something.

Thanks
Prasad

On Sunday, November 3, 2019, 04:02:39 PM EST, Dave Schwartz <dave.schwartz@...> wrote:


This is typical (expected) behaviour if OnStep thinks you are close to a celestial pole... the direction of north keeps changing if your last north slew passed through a closest approach to the pole.

If you did not do any sort of alignment then who knows where it thought you were pointing when you turned it on and moved to the sun. When you turned it off, the model would have been reset and your perceived issue would have not appeared.

On November 3, 2019 1:31:37 PM EST, "Prasad via Groups.Io" <ad_prasad=yahoo.com@groups.io> wrote:

This morning I had my OnStep controlled Vixen GP mount out on the
deck and I was observing the sun. Since I had not done any polar
alignment sun was drifting. So I had to, sometimes, push a
direction button on my phone that runs the OnStep app to bring sun
back to the center. Everything was fine until about 2 hours into
the session when I noticed the misbehavior. When I make a
quick/short push on North button my scope would go the other way.
Push the same button again then it went the right way. A third
push would make it go the wrong direction and back in the right
direction for the next push. I think I had experienced this
behavior once before but I ignored it blaming it on an operator
error.

I did a power reset and all was fine after that. I wonder what was
the cause?

Prasad


--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Prasad
 

Wow, that explains it. Initially I had started moving it to point at the sun using the phone app but after a few seconds I changed my thinking to moving it manually. OK, I get it. It has to go through the slewing sequence. A useful lesson learnt. 

Thanks for the help
Prasad

On Sunday, November 3, 2019, 05:19:10 PM EST, Dave Schwartz <dave.schwartz@...> wrote:


Did you set up the mount in approximately the home position, move it
manually to the sun and then power on and enable tracking? If so, it
would have thought you were pointed at the pole and you would have seen
this behaviour. First question in the FAQ
https://onstep.groups.io/g/main/wiki/Frequently-Asked-Questions-%28FAQ%29.

On 2019-11-03 5:03 p.m., Prasad via Groups.Io wrote:
> That's odd because I live at 40 degree latitude, near Philadelphia PA.
> I must try again and see if I missed something.
>
> Thanks
> Prasad
>
> On Sunday, November 3, 2019, 04:02:39 PM EST, Dave Schwartz
> <dave.schwartz@...> wrote:
>
>
> This is typical (expected) behaviour if OnStep thinks you are close to
> a celestial pole... the direction of north keeps changing if your last
> north slew passed through a closest approach to the pole.
>
> If you did not do any sort of alignment then who knows where it
> thought you were pointing when you turned it on and moved to the sun.
> When you turned it off, the model would have been reset and your
> perceived issue would have not appeared.
>
> On November 3, 2019 1:31:37 PM EST, "Prasad via Groups.Io"
> <ad_prasad=yahoo.com@groups.io> wrote:
>
>    This morning I had my OnStep controlled Vixen GP mount out on the
>    deck and I was observing the sun. Since I had not done any polar
>    alignment sun was drifting. So I had to, sometimes, push a
>    direction button on my phone that runs the OnStep app to bring sun
>    back to the center. Everything was fine until about 2 hours into
>    the session when I noticed the misbehavior. When I make a
>    quick/short push on North button my scope would go the other way.
>    Push the same button again then it went the right way. A third
>    push would make it go the wrong direction and back in the right
>    direction for the next push. I think I had experienced this
>    behavior once before but I ignored it blaming it on an operator
>    error.
>
>    I did a power reset and all was fine after that. I wonder what was
>    the cause?
>
>    Prasad
>
>
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.
>



Bojan
 

On Sun, Nov 3, 2019 at 02:45 PM, Prasad wrote:
This is situation when encoders are very useful...