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PEC in PMC-8


Dan Winn
 

Looks like PEC is not yet implemented in PMC-8.  Has anyone looked at implementing this in the software?  Anything about the hardware that fundamentally prevents it?


r_hoskin@...
 

Dan,

There was a 'new mount coming' thread on this over at Cloudy Nights a while ago, that should help you with your question.

First page of the thread is just chatter. Later on page 2, Scott Roberts jumps in and introduces Jerry, then Jerry pick up for the following pages.  If you read through his posts in that thread, he lays out his rationale for omitting PEC in rather a lot of detail.  He raised some eyebrows with that, and it made for an animated discussion - I thought it was pretty interesting. 

https://www.cloudynights.com/topic/527714-new-es-mount-coming-to-market/page-2


- Bob


Dan Winn
 

Super helpful.  Thank you, Bob.  I hadn't seen that thread.

Jerry (or anyone else at ES), is there any thought to open sourcing the PMC-8's firmware?  This would enable the community to consider implementing PEC, improving wifi support, and might get you out of doing the custom builds for auto-guider configs I saw referenced elsewhere...


hubbell_jerry@...
 

Hi Dan,

No, the firmware is our intellectual property and is the heart of the PMC-Eight system. Making the firmware open would be giving the store away. We have spent hundreds of thousands of dollars and 4 years of hard work to get the system where it is. So that is not going to happen.

We have shared our command language so that it is easy to implement your own programs using the command language directly, or if you want to create an ASCOM client, you can use our driver to develop it as you see fit.

The custom firmware I build for the ST4 calibration for user cameras is currently just a work-around and is not meant to be a long term design. It's a long story, but suffice it to say, the current analog multiplexer design for the guide port inputs was a design compromise which will be solved in the next version of the PMC-Eight system for the G-11 and EXOS 2. 

There are changes that can be done to the driver to make it more transparent for the user to switch from WiFi to serial. Solving the ST4 calibration for existing PMC-Eight customers would require a firmware update, but that is not priority at this time. Fortunately, acquiring the necessary data and installing the customer firmware does not take long. I will probably create another Application Note on how to get the data and how to submit it to me to receive a customer firmware binary file to load onto your system. 

Thanks

Jerry Hubbell
Director Electrical Engineering
Explore Scientific, LLC.


hubbell_jerry@...
 

I meant to say something about PEC.  The mounts that we sell do not have a worm position sensor to synchronize the worm position with the correction curve so it cannot be implemented. Now, if the user is willing to have to acquire a PE curve every time he starts up, then that possibly could be done in the ASCOM driver. This would stick until the clutches are loosened and the scope repositioned. Even with this, the worm itself still doesn't move, so as long as the worm/motor is not moved when the power is off the mount, then, theoretically, the worm is repositioned back to its beginning place when the mount is homed, or parked.  As you saw in my postings on CloudyNights, there wasn't and still isn't a pressing need for this.

Thanks

Jerry Hubbell
Director Electrical Engineering
Explore Scientific, LLC.