Erroneous goto slews...
The Raspberry Pi is connected to my Star Watcher EQ6-Pro mount through a USB/D-sub 9 pin cable bought at a specialized store.
- mount is polar aligned, usual observation site coordinates: 48.767122, 1.539318,
- mount is set to the home position.
- While operated through the SynScan handheld control provided with the mount, once the initial setup is done (coordinate, time, etc.), I’m able to 3-star align the mount and to goto to various objects afterwards, with only small corrections needed.
- While operated using Kstars on the Macbook through the Raspberry Pi, after having set the geographical position accordingly and checked the date & time, I’m able to slew the mount from Kstars.
When the mount is connected to the Raspberry Pi, there is no way I can goto any object. Any object that I select will make the scope pointing to a completely different position. I explored a possible date and time mismatch, but this is not the cause for the scope will point in a direction where the target object cannot be. For instance, when instructed to goto the Moon, it would point a direction that is definitely not on Moon’s path, no matter the date.
The mount will go back to the home position if the Park button is pressed on Kstars.
I considered the possibility of a geographical coordinates mismatch, but the location selected in Kstars matches the current position of the mount. I have tried to select the city of Paris that is 50 kilometers straight east, which shouldn’t make a huge difference, but with no avail.
I’m at my wit’s end here and I wonder if someone may have some pointers for me…
knro wrote: Hi Ron,
Did you check the date/time on StellarMate? is it correct?
Okay, if my Kstars runs on a Macbook that is connected to Raspberry Pi running Stellarmate, is the Pi's clock any relevant?
And again, a date & time mismatch would make the scope slewing to a position the object would be, not to a position the object cannot physically be!
Also, do you have it set in the KStars options to sync the date and time and coordinates from the computer to the device? When you connect, this would change the date, time, and location on the mount. This would be desirable in most cases since the computer clock and location is more likely to be correct and since they will match now. It would not be desirable if in fact the computer's date, time, or location is wrong since that will then change the mount's information to be incorrect. If you aligned using the hand paddle and then it updates the date, time, location from the computer and one of those is significantly wrong, then yes your gotos would be insanely wrong.
My recommendation is to make sure that your computer's information is all correct and make sure KStars is set to sync the time and location with the mount. Connect using the EQ Direct cable. Then turn on your mount. Then plate solve a couple of times and you will be good to go.
rlancaste wrote: When you say you did the alignment, do you mean that you plate solved in 3 different places in the sky or that you did the mount's 3 star alignment with the hand paddle before connecting the eq direct cable?
Thanks for your answer. No, as I said, I did the 3-star alignment with the handheld. No Kstars involved. This was just to check if there was nothing wrong with the mount itself before trying to plug Kstars. I'm unfortunately nowhere close to do plate solving yet. Connecting the Raspberry Pi with the EQDirect cable to the mount and being able to connect the Macbook and having Kstars slewing the scope was already an achievement for this noob!
rlancaste wrote: Also, do you have it set in the KStars options to sync the date and time and coordinates from the computer to the device? When you connect, this would change the date, time, and location on the mount.
Okay, I don't think I did that. I need to investigate how to do it.
rlancaste wrote: This would be desirable in most cases since the computer clock and location is more likely to be correct and since they will match now. It would not be desirable if in fact the computer's date, time, or location is wrong since that will then change the mount's information to be incorrect. If you aligned using the hand paddle and then it updates the date, time, location from the computer and one of those is significantly wrong, then yes your gotos would be insanely wrong.
Which again brings me to my previous question, in my configuration in which the Raspberry Pi acts as an INDI server, the Kstars client being on the Macbook (well, that is if I got this right), which clock are we speaking of here? The Macbook's (my guess), or the Raspberry's?
In the meantime, I've got new developments. Last time I set the gear up, the problem didn't materialize. But then someone else operating a similar mount started to complain because his gear began to slew erratically, just the same way mine did the time before.
So, I disengaged my mount and slewed it around manually a bit, then I locked it back and parked it. I restarted everything and there you go, crazy slews again.
I switched the power off and on again few times and everything returned to normal. At this point I need to perform some more tests to confirm my current theory, but I believe that the mount keeps a kind of state (does an SW EQ6-Pro have such a memory?) that has to be reset at some point.
I'll keep you guys updated...