Random N / S direction change Onstep Android app.


 

‌Hello,
I just saw when using the Onstep app on Android (tablet) that the N / S direction was random.
Let me explain: I press the N key, the telescope goes south. I press the S key, the telescope goes south, I press the N key again, the telescope goes north. After all is back to normal. The case is random and does not always do.
Sometimes it is enough to press the E / W keys (which have no problem) for this to happen again.

Any ideas?

Thank you!


adraasch
 

How close to the pole are you when you make these moves?

Arlen

On Tue, Aug 3, 2021 at 11:07 AM Dahle <dahle@...> wrote:
‌Hello,
I just saw when using the Onstep app on Android (tablet) that the N / S direction was random.
Let me explain: I press the N key, the telescope goes south. I press the S key, the telescope goes south, I press the N key again, the telescope goes north. After all is back to normal. The case is random and does not always do.
Sometimes it is enough to press the E / W keys (which have no problem) for this to happen again.

Any ideas?

Thank you!


Chad Gray
 

I also questioned this.  The N/S gets flipped depending on how close you are to Polaris.  I think there is an explanation on the FAQ.


On Tue, Aug 3, 2021 at 11:16 AM adraasch <araasch@...> wrote:
How close to the pole are you when you make these moves?

Arlen

On Tue, Aug 3, 2021 at 11:07 AM Dahle <dahle@...> wrote:
‌Hello,
I just saw when using the Onstep app on Android (tablet) that the N / S direction was random.
Let me explain: I press the N key, the telescope goes south. I press the S key, the telescope goes south, I press the N key again, the telescope goes north. After all is back to normal. The case is random and does not always do.
Sometimes it is enough to press the E / W keys (which have no problem) for this to happen again.

Any ideas?

Thank you!


Drew 🔭📷🚴‍♂️
 
Edited

It doesn't really depend on how close you are to Polaris. It has everything to do with true North and the direction you pressed on the controller.

Here is how I explain the behavior.

The basic rule is that it always wants to go North when you press the N button.

OnStep starts with the telescope at NCP (North Celestial pole). Pressing the N button will cause the telescope to head South. This is the only direction it can go since it is already at North. Release the button and press North again. It will reverse direction because now it can and will go North. Keep holding the button passing the polar axis (scope aligned with mount) and it  will continue, but now it is actually going South. Let go of the button and press North again. It will reverse direction again,  heading North.

This can take awhile to wrap your head around. Play with it and it will become obvious.  Of course, all of this is reversed for our friends below  the equator.


Khalid Baheyeldin
 

This is the most Frequently Asked Question on OnStep. Read the link.


 

Thank you for all the answers.
Indeed it's my fault because having a new mount (friction mount from JTW Astronomy) I wanted to see its behavior during changes of direction ..... without using a celestial map !! therefore impossible for me to know where the telescope was pointing! and indeed, if at Onstep startup it points the NPC and my telescope points in another direction, there can only be one big problem!

Thank you all once again!