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Re: Help needed re: connecting Gemini 2 to PC
David,
Good to hear from you.? I am also a dedicated MI-250 user. I got mine from the original owner back in 2005, and it has performed perfectly ever since. My Gemini I that just got fried was the one that came with the mount back in 2005, so I guess I can't complain about it finally shooting craps. Can't think of another electronic device I bought in 2005 that is still working!
Thanks for yur advise.
Ron |
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Re: Need advice on strange guiding problem
开云体育Paul,I should be able to get an unguided log tonight. Yes, Gemini 1. ?The autoguider is connected to the main camera, which in turn is connected to a Raspberry Pi 4. ?The RPi4 also has a USB cable coming out that goes into the RS232 port on the Gemini 1 (via a USB to serial converter). ?Pretty sure I’ve tried the autoguider plugged directly into the RPi4, but I can try that again to see if if there are any differences. Bill
--? Bill Tschumy Otherwise -- Longmont, CO www.otherwise.com |
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Re: Need advice on strange guiding problem
So the calibration looks good. How about an unguided tracking log over a few worm cycles?
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This is with Gemini-1, correct? How is your autoguider connected to Gemini?
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Regards,
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? -Paul
On Sat, Sep 28, 2024 at 12:44 PM, Bill Tschumy wrote:
Paul, |
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Re: Need advice on strange guiding problem
开云体育Paul,I have calibrated and re-calibrated many, many times. ?I have also tried a variety of different pulse lengths for calibration. ?If calibration is off then there must be some other fundamental problem that is causing it. ?I’ve attached the Calibration Plot that Ekos generates. ?It doesn’t look particularly bad to me. I do use a somewhat longer pulse length (around 1250 ms) because if I do shorter the Dec calibration looks worse. Sometimes the Dec calibration dots can be a bit squirrely although the ones here look fine to me. I should also mention that I’ve tried adjusting the RA worm play ad nauseum and that doesn’t seem to help. Bill
--? Bill Tschumy Otherwise -- Longmont, CO www.otherwise.com |
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Re: Help needed re: connecting Gemini 2 to PC
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The easiest way to connect to a Gemini 2 using Ethernet directly to a PC Ethernet port is to use Ethernet crossover cable or IME a crossover adapter with a standard CAT5/6 cable of appropriate length. I say this is easiest because even though the vast majority of computers these days have Ethernet ports that should automatically . detect what kind of connection they are talking to many people cannot successfully make a direct connection without using a crossover cable / crossover adapter or use a router to manage the connection.?
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Also you can order and receive a crossover adapter from Amazon very quickly as well as a CAT5/6 patch cable as they are cheaper and involve a bit less setup to be successful than using a small router. Using router has its advantages but you may or may not have a use for what a router can bring to the table.? ?
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Chip Louie Chief Daydreamer Imagination Hardware? ? ?Astrospheric - South Pasadena? |
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Re: Need advice on strange guiding problem
Hi Bill, it looks like to me that the autoguider isn't calibrated properly. Corrections are often insufficient in RA, and sometimes overshoot a quick jump. The first step is to measure your periodic error during tracking (capture a few cycles of tracking error while not guiding). See what tracking looks like without autoguider corrections. Then, a guide log may help diagnose what's going on while guiding is engaged. PHD2 also has a number of diagnostic/calibration tools that may help figure out what's going on.
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Regards,
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?-Paul
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On Sat, Sep 28, 2024 at 11:03 AM, Bill Tschumy wrote:
Group, |
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Re: Help needed re: connecting Gemini 2 to PC
Hi Ron,
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First, Serial/RS232 is fully supported by Gemini-2, not sure why you say it isn't. Ethernet is definitely a better way to go, if you want to get the best out of the PC->Gemini link. Is your PC connected to a WiFi or other (home?) network, in addition to being connected to Gemini? If so, there's a little PC networking configuration that may be required, in addition to using a cross-over Ethernet cable (or a switch/router) that's already been mentioned. Here are some instructions that may help:
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Regards,
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? -Paul
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On Fri, Sep 27, 2024 at 10:16 PM, stargazer66207 wrote:
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Need advice on strange guiding problem
Group,
I have been trying to use a 14 year old GM8 mount (non-spring loaded worms; non-tucked motors) for variable star analysis. For this analysis, it is not essential that guiding is perfect, but I’d like to get it better than I’m currently achieving. This is with a small refractor of 740mm focal length. The crux of the issue is that guiding in Dec seems to be reasonable (say 0.3 RMS”) but RA guiding is significantly worse (say 1.5 RMS”). I’ve attached a screen shot showing what the RA guiding looks like (blue is Dec; green is RA). I am using KStars/Ekos for imaging and guiding but I get similar results if I use PhD. The RA seems to bounce around somewhat chaotically. I do have pretty bad seeing where I’m located, but the fact that the Dec doesn’ bouce around as much indicates this in more than bad seeing. I have been working on this problem off and on for some time. I have tried. 1. Stripping the mount and completely cleaning/relubbing it 2 or 3 times 2. Swapped the worm and worm blocks between RA and Dec axes 3. Swapped the gear boxes between RA and Dec axes 4. Swapped the motors between RA and Dec axes 5. Shimmed the RA gear box to correct a slight misalignment at the Oldham coupler 6. Tried lubricating the Oldham coupler 7. Shifted the counterweight around to make it East heavy and East light 8. Tried a different power supply None of this has made a significant difference. I still get poorer guiding in RA. Anyone have any ideas on what is going on and how I might fix this? Thanks, Bill -- Bill Tschumy Otherwise -- Longmont, CO www.otherwise.com |
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Re: Help needed re: connecting Gemini 2 to PC
It might work as you connected them, if one or both ports are auto switching,
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More than likely, you will need a hub or switch connected between the two.
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Another possibility is to use a "cross-over" patch cable, assuming you are not already using one.
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Your post is coincidental to what I will need to do for my recent upgrade of an MI-250 mount from Gemini I to Gemini II.
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Help needed re: connecting Gemini 2 to PC
Hello group,
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Recently my trusty old Gemini I shot craps after 19 yrs of faithful service. I had to upgrade to the new Gemini 2 and Hand Controller.
As you know, the old Gemini I connected to a PC via a Serial/R12 connector cable which plugged in to one of the RJ 12 sockets on the control box. This does not work on the new Gemini 2.
I decided I want to connect via an ethernet cable (Cat 5) directly from the Gemini 2 to the ethernet port on my PC.? I have now installed this.
My question is: Now that I have the connection, what are my next steps to make it operational so that I can use programs like The Sky 6 and N.I.N.A. to run my mount?? I am a Newbie to Gemini 2, so any assistance you experienced Gemini 2 users can give me will be greatly appreciated! Thanks.
Ron Abbott |
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Re: North Dec button not working
开云体育Brendan,Are you saying that a standard VGA cable will work? ?I have several of those laying around. ? I don’t understand your comment about “Aldo”. ?Is that a particular manufacturer? ?Or is this a comment that VGA cables will not work? Can you give me a link to one you know works? Bill
--? Bill Tschumy Otherwise -- Longmont, CO www.otherwise.com |
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Re: North Dec button not working
开云体育Sorry for the delayed answer. ?Yesterday I was playing with the mount and noticed the North button was working again. ?After a few experiments I found that it was indeed the cable between the HC and the Gemini unit that was going bad (René was right). ?If the cable is flexed one way it fails and if flexed the other it works. ?I could probably temporarily work around it by splinting the cable.It doesn’t seem that Losmandy sells replacement cables for the Gemini 1 anymore. ?Anyone have an idea where to get one or a suitable substitute? Bill
--? Bill Tschumy Otherwise -- Longmont, CO www.otherwise.com |
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Re: North Dec button not working
开云体育Brendan,Thanks for the additional info. ?I will test this tomorrow. Bill
--? Bill Tschumy Otherwise -- Longmont, CO www.otherwise.com |
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Re: North Dec button not working
Hi Bill, I'm home now so can attach more info on this:
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Just remember the "DEC+" out (Pin 9 HC)? becomes DEC "-ve" when "REV DEC" is selected.??? This is why the fault appears to change.?? In reality it doesn't as it uses same HC pins and by proxy Cable pins and wire.
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It comes in Pin 9 on main board to D3.? When you press "DEC +" this point "D3 Anode" will go high as long as button is pressed.?? See diagrams
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A cheap small Multimeter will suffice.
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“顿贰颁+”: DEC+ is out pin 9 J1 to Pin 9 J10 to diode D3 (& R2 to GND, main PCB). The cathode side D3 (between the D3 and R2) is fed to CPU pin 14. Depressing DEC+ you can measure at D3 or Pin 14 (CPU) for a “high”. ?
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Any more assistance....fire away
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cheers
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Brendan |
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Re: North Dec button not working
On Tue, Sep 10, 2024 at 02:37 PM, Bill Tschumy wrote:
Michael Hermann also thinks the logic chip is the likely culprit. ?Can you even get another of those now a days? ?
Back in the ancient days when digital stuff was more flakey and there were no real I/O chips we used to use ICs to buffer/hold data bits for downstream controllers to read the last data bits or sometimes used them to hold status bits. I think whatever holds these bits is stuck or faulty.? It used to happen on occasion and something like this could be what is happening here.? ? ?
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Chip Louie Chief Daydreamer Imagination Hardware? ? ?Astrospheric - South Pasadena? |
stargazer66207
Bill Tschumy
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