@JA I'm skeptical I am 'lucky' because I cant see how the tracking issue would cause such huge spikes in dec. I think maybe theres multiple issues at play here. But yeah solving RA would be a great great start and you never know might mysteriously fix dec.
Have some one look at the voltage supply / current used by the motors as a function of time. Perhaps a faulty component or one damaged by the mount crash.
PS: Can you also try a hand controller on the mount with no guiding, just tracking in case something is getting garbled somewhere?
you had me doubting myself, but I did say rowan mod right at the start.
I did try looking at the pulses to the steppers with a home brew arduino oscilloscope, but it was a bit chaotic in there Would love to be able to get some internal info on whats going out to the stepper motors
As I understand it the tracking is handled by the cpu on the PCB. the hand controller /eqmod simply tells the pcb to track or not to track, and what the tracking rate is I wonder if I can pull the eqmod cable and have it still continue to track that could rule out random comms signals doing stuff.
you had me doubting myself, but I did say rowan mod right at the start.
My bad.... Looks like I missed that
Quote:
Originally Posted by dizzy2003
As I understand it the tracking is handled by the cpu on the PCB. the hand controller /eqmod simply tells the pcb to track or not to track, and what the tracking rate is I wonder if I can pull the eqmod cable and have it still continue to track that could rule out random comms signals doing stuff.
That's interesting .... perhaps that is what is going on/off intermittently? It might be instructive to test the mount with only tracking initiated via hand controller alone and then look at the images for any star trailing.
Well heres an interesting result, its still ongoing testing but.
I setup with asiair as normal to make sure I was getting errors. so asiair guiding and doing 60 second exposures seeing spikey errors as usual.
So then I stop the asi guiding and plug the guidecam (asi 120mm) into my laptop and run phd2. (I actually home the mount then point it back to m20 which I wish I hadnt done should have just left it).
But the phd2 monitoring isnt showing any spikes, its showing very bad polar alignment and its showing pec errors but otherwise its normal enough.
I plug the guidecam back into asiair (enable guiding on asiair) and the spikes are back.
My initial reaction is the asi 120mm is some how causing USB errors that are sending the mount crazy.
This is very promising news.
Edit:
When I switched to laptop I used a longer cable from guidecam to computer, am now trying that cable with asiair guiding, if its the usb cable from the guidecam that would be a huge win (cheap) at the same time also mega frustrating that its been months to narrow it down to this 1 thing. Normally this short (40cm) usb c cable would have been plugged into either the asi533mc as a hub or direct to asiair (I tried both incase it was the asi533 hub)
Its been about 4 mins with the new cable and no spikes and rms is at .58''
But scope is almost at miridian so it could be that its coincidentally at a good spot.
Edit2: spoke too soon just had a 8 arc second spike after about 6 mins on new cable
attached is an image of the laptop monitoring the ra /dec error with phd2. while asiair was imaging and was connected to the mount.
Just to be clear I think this is pretty good (polar alignment was crap, we are really just seeing pec and probably some atmospheric noise certainly no gremlin spikes)
On the subject of my bad polar alighment, I align repeatedly with asiAir get it under 30 arc seconds, but meansuring it its often 8 arc minutes out!
My suspicion is that when asiair requests the mount to turn 20 degrees in RA, it might only do 19.6 because of these issues I have, resulting in the maths being ot and the polar alignment ultimatly being wrong. I look forward to trying the polar alignement without the 120mm to see if its aligns better
So
- no spikes when not guiding = nothing wrong with mount
- no spikes when guiding through a PC = nothing wrong with camera, guiding and cables
- spikes when guiding through asiair = something wrong with the ASI air or specific cables used with It?
So
- no spikes when not guiding = nothing wrong with mount
- no spikes when guiding through a PC = nothing wrong with camera, guiding and cables
- spikes when guiding through asiair = something wrong with the ASI air or specific cables used with It?
Great detective work
No Not quite.
The PC and asiair both suffer same spikes.
At this point it appears to be the asi 120mm camera, which is ironic because I cant guide without it and its guiding that I always use as a test to see the spikes in PHD2, and its probably about the one thing thats been consistently plugged in through all my tests. I have always just assumed it must be the mount (having bene through the power supply and eqmod cable alternatives) that the camea worked but produced usb comms errors was not on my radar.
It was only when the asiair controlled the mount (really just leaving it tracking) and the guidecam was connected to the pc as a phd2 monitoring tool that I got good phd2 results (no spikes)
So my next test will be recreate the spikes (easy) then disconnect the 120mm camera and use the asi 533 for guiding. view the guide graph, do I get spikes, swap back and forth a bit. If it still indicates the asi120mm is the problem, double check with a few different usb cables on the asi 120mm.
Assuming it is the asi 120mm and not a cable or two! (unlikely) I will make a warranty claim, its 2 year warranty and is 18 months old.
Am really hoping its not just random coincidence playing with my conclusions. and it really is the guidecam.
Hmm….
I had ongoing issues with PHD2 using the 120MM USB2 camera
Bought the 120MM-S USB3 camera and has been working flawlessly ever since
Which 120MM camera do you use ?
The older 120MM USB2 camera did have inherent connectivity and data flow problems ( ZWO offered a driver patch but I ditched the camera )
If your using the 120MM-S USB3 with a quality certified USB3 cable no longer than 1.5m ( eg Startech brand or similar ) then ignore this post
Cheers
Martin
Its described on the invoice as "ZWO ASI 120MM Mini Guider"
It has a usb C connector and a st4 connector. and came with a cable 1.5m , but I think I may be using a cable that came with the asiair pro its a very small one. But It might just be a cable I bought at some point, to have a short cable to the asi 533mc hub
I use the 120MM Planetary camera for guiding , not the mini
As far as I know the Mini cameras are ok provided you have all the latest ZWO and Ascom drivers installed and latest windows updates
Just another suggestion , have you checked the power management of your USB drivers on your computer
Attached is how to check Windows 10
I’ve been watching this post with interest although I haven’t had any solutions so that’s why I’ve stayed quiet. From the last few posts where you seem to be leading towards the camera, I just want to clarify something. Is your 120MM mini connected to your camera as a hub or directly to the AIR ? I have always run mine direct to the AIR. It all seems a bit interesting though given it’s something that has just started happening.
I use the 120MM Planetary camera for guiding , not the mini
As far as I know the Mini cameras are ok provided you have all the latest ZWO and Ascom drivers installed and latest windows updates
Just another suggestion , have you checked the power management of your USB drivers on your computer
Attached is how to check Windows 10
Cheers
Martin
Yep the windows usb power management was an early attempt to fix (I should have included it in my initial post). Plus wouldnt be relevant for the asiair.
My computer asi drivers probably are a bit out of date, but the asiair is bang up to date.
Doesnt look like theres such a thing as firmware for the camera so thats a shame.
I’ve been watching this post with interest although I haven’t had any solutions so that’s why I’ve stayed quiet. From the last few posts where you seem to be leading towards the camera, I just want to clarify something. Is your 120MM mini connected to your camera as a hub or directly to the AIR ? I have always run mine direct to the AIR. It all seems a bit interesting though given it’s something that has just started happening.
Cheers
Ryan
As part of my trouble-shooting I have tried both, as at one point I thought maybe its the asi 533's usb hub because I had seen people having issues with USB hubs. Either direct or via 533's usb hub spikes happen.
As part of my trouble-shooting I have tried both, as at one point I thought maybe its the asi 533's usb hub because I had seen people having issues with USB hubs. Either direct or via 533's usb hub spikes happen.
I must say it’s a really interesting problem you’re having. The non periodic nature rules out some things and the fact that it’s the same magnitude excursion but on both axis really does confuse things. I shall continue to watch. I hope you find a solution to it.
I must say it’s a really interesting problem you’re having. The non periodic nature rules out some things and the fact that it’s the same magnitude excursion but on both axis really does confuse things. I shall continue to watch. I hope you find a solution to it.
Probably a long shot, but do you know anyone local to you with a known-working mount that you could put your cameras and ASIair onto?
You seem to have tested just about everything else.
Cheers,
V
Unfortunately no.
I dont think the cameras or the asiair are the issue anyway (now).
Its unlikely the 120mm and the 533mc both have the same issue.
Its unlikely my windows laptop and asiair both have the same issue.
Currently wondering if the spikes were combined from both cameras would that display a similar frequency to when I have normal guiding and image capture going on. And if so that would imply more traffic on usb equals more errors. having said that normal imaging would not create much USB traffic from the imaging camera (once every 60 seconds or whatever the exposure is)
The only thing I really have conclusive is sending guide pulses to the mount seems to cause spikes, and the spikes are in proportion to the guide rate.
because I cant see how the tracking issue would cause such huge spikes in dec. I think maybe theres multiple issues at play here. But yeah solving RA would be a great great start and you never know might mysteriously fix dec.
