serial to usb vs serial to parallel

[DrRichy]

I am getting ready to purchase some minor hardware/software for connecting my Meade telescope with Astro Finder to my laptop. The Astro Finder kit includes a cable with a 4 pin phone type connector (from the telescope) and the other a DB-9 serial port connector (to the laptop). The Astro Finder information states that, "If you have a laptop with a USB port instead of a DB-9 serial port you will have to purchase a USB to serial adapter from your local computer store."

My question is this.... Since I have several items already packing the 2 USB ports on my laptop, a quad adapter in 1 and a mouse in the other, can I simply add a AT Serial Adapter, DB9 pin Female to DB25 pin (Parallel Port) adapter. I have one unused/never used Parallel Port open on the laptop.

It is my understanding the only differences with the port types is information packet size. Since the data transfer leaving the scope was origionally intended for connection to a serial port nothing would be lost by using the potentially faster parallel port.

I would appreciate any clarification and/or help.

Thanks
DrRichy

[Wandrille]

so wait r u tryin to plug it in to a different DB port
if they dont have the same number of pins lets just say that ull be havin fun rammin it in
thurs no way u can plug in different number of pins

[DrRichy]

As I noted previously, Can I simply use an AT Serial Adapter, DB9 pin Female to DB25 pin. True I am a neophyte in some respects but the difference between a 9-pin and 25-pin connection port is rather obvious.
Thanks for the input.

[jlreich]

Is this what your looking for? http://www.computercablestore.com/SearchResult.aspx?CategoryID=699

I would guess you can pick one up just about anywhere local. Circuit City, BestBuy etc..

I figure if they make an adapter for it then it should work. In theory anyway. :p

[Wandrille]

o u just wanted an adapter
u shuld have just asked lol (jokes)

[DrRichy]

I think I had better state this in a different way. Hardware, is not the problem.
Can a LPT (parallel) port be reconfigured to receive Serial port data?

[beerbelly]

Check out Cables to go. (http://www.cablestogo.com/product_list.asp?cat%5Fid=101&engine=adwords!654&keyword=%28db9+db25%29)
I would think you just plug it in and it will work. I'm sure someone will correct me if I'm wrong.

[Paleo Pete]

Sometimes yes, sometimes no. You can try it and see, but I think it probably won't work. The Meade cable is going to communicate with he computer similar to the way an external modem does, since it uses a serial port, and probably won't work correctly on a parallel port, due to the difference in the way they work. Serial can't handle the return traffic. I had the same connector on my old telescope but never found just the cable, so I never used it. Everyone wanted $40 or more for cable AND software, I already had the software, just needed the cable...anyway, my current scope, an Orion Skyquest 6 incher, (I like the Dobsonian mount) is all manual and has no electronics, so it's no longer an issue for me, and I LIKE the new scope...I was going to try and make the cable for the old one, from an old phone cord, but I found out the connector on the scope is the one from the handset, not the wall plug, they are different, and I didn't have one lying around. You can get the DB-9 plugs easily. All I could find here for handset cords were the coil cords and that would really suck for telescope and laptop usage...

Check your laptop, it might have a serial port already and unused, many do have them since a lot of people used external modems with them or serial mice. Mine has one but it's an older P-II 266, not a newer laptop. If it does have a DB-9 serial port, just use that. If not, get a USB hub and an adapter, having several USB devices won't hurt a thing, USB is designed to use numerous devices at one time. USB hubs usually plug in and work with no software installation necessary, and the extra cable can be helpful, especially with a telescope, since you want the scope and laptop far enough apart they don't interfere with each other and the light from the display does not ruin your night vision. Trust me, the display is certainly bright enough to ruin your night vision. I use Linux, which has its own star chart program, I have to put my laptop in the bed of my truck to use it, and set it up for the night vision display, and the toolbars are still bright enough I have to let my eyes adjust again after looking at it. I've basically quit using it, I print out charts of the areas I want to look at and use a red filtered flashlihgt to look at the charts. Just don't mark objects you want to look for with a red sharpie... :eek: I did that once, didn't realize it would cancel out the red ink till I tried to look at it with my flashlight...dumb, dumb, dumb.... :rolleyes:

I know this is going to throw this thread way off topic, but I'm curious, what Meade scope do you have? Mine was a small beginner scope, 60mm refractor, great for a beginner and I was quite pleased with it. I just went to a "star party" recently with a local astronomical club and got to see Meade's 8", 12" and 14" Schmidt-Cassegrain scopes, those are really nice. Check Ovalskies (http://www.ovalskies.com/) for some nice pictures taken by some of the local guys, some of them with larger Meade "light bucket" scopes. Unfortunately the pictures taken the night of the star party have been taken down in the past day or two, they got some really nice shots of a couple of galaxies and star clusters, Ring Nebula, Dumbbell Nebula, Crab Nebula and several other deep-space items. I missed the Mars viewing, was going to take my scope and join in but by the time I got ready the clouds were rolling in, I got a late start because I had some carpenter work to do that day and couldn't be ready to go till after dark. Soon as this nasty weather rools on through I'll be out there bundled up and staring at the sky...I plan to try and get some more moon pictures before full moon, since my scope is all manual I can't track, so I can't get deep-space photos, but I can see Jupiter, Saturn, Mars, Venus, the Ring Nebula, Dumbbell Nebula, Orion Nebula, Double Cluster and Andromeda galaxy from the back yard, and lots of other goodies if I head out of town a few miles to some dark sky...

Keep looking up!

[DrRichy]

You have captured the root of my problem to a tee! As it turns out you are very right.
I connected the line as stated. Modified the port address in the system manager and was able to access the handheld of the scope. But……!!!! As you recognized the two way communication with the device, primarily due the software design, communicates only through com ports. This is easily modified to USB for pass thru data. I was simply trying to avoid having to buy another ganged USB (6+ port) hub. Oh well. And no the Toshiba A35-S159 is not supplied with a serial port.

“If all the world is a stage, where is the audience sitting?

Latitude 34° 29´N
Longitude 114° 21´W
And below my Elevation at 210 meters, a place where 350+ nights are perfectly clear category 5 (4 in the summer due to thermal aberrations) viewing! A little bragging rights taken here after seeing the “Clear Skies Chart” at the bottom of the Ovalskies website….LOL! Great photos by the way.

Threading off the topic as you say, I am putting together a little backyard technical entertainment center, for ME, when the evenings are short and it is to cold for the H2O sports. The main scope is AR-5, using LXD75 mount and stationary pier with a piggybacked DS-80mm as an electronic guide scope using GuideDog software. I am in the process of modifying a QC4000 to a SC4 configuration and using a Minolta DiMage A2 coupled with a MaxView II. Who know how well this will work, I’m a newbie in this arena. But from experience it’s the journey not the destination!

Thanks for your excellent response!

[Paleo Pete]

I wasn't positive, but suspected that would be the case, since parallel has the return signal it would require compatible programming.

Sounds pretty good, the Meade site says the AR-5 is a refractor, which should probably be better than a reflector for photography. I'm not familiar with the other scope by model, or the imager, so I can't say much about either, but my smaller NGC 60 refractor did quite well for an inexpensive, entry level scope. Meade makes or uses good optics, even in their lower end and beginner scopes.

Yeah, the viewing quality around here pretty much stinks, I have to get at least 10 miles outside town to get a decent look around. 30 miles is better...Fortunately the closest town is small, nothing like one of the larger cities, I'd hate to try and use a scope anywhere within 75 miles or so of Houston or Dallas. :eek:

I'm not too familar with this type of photography either, since neither of my scopes has/had the ability to track objects for the necessary long exposures. About the best I can hope for is a few 5 second moon shots. I did find out I can get a decent moon picture just before dark with a digital camera on a tripod almost touching the telescope's eyelens. I got one shot last fall that turned out really nice of just under a half moon.

As far as what I've picked up so far about astrophotography, your scope needs to be able to track solar system or deep-space objects very closely and without vibration, to get a clear image. Meade motor drives are usually pretty good at that. If the tracking is slightly off, you'll get an elongated image. different color and type filters are used to get color images, then "stacked" on top of each other, usually by software these days, to compose a final color image. Don't expect to get the kind of detail and resolution you see on websites, such as the one I posted. Most of those are taken with 12" and 14" scopes, almost 3 times the size of yours, so that scope is optically unable to match the resolution and detail of those. It still should get some good images, especially of the moon and planets. I've seen pictures taken with 8" scopes of Saturn and Jupiter that were nice, and with the kind of viewing conditions you descrine, the 5" scope you're using should get some nice shots, possibly as good as an 8" scope in poorer viewing conditions..

I suppose it might also be a good idea to post a quick reminder...

DO NOT look at the sun through any telescope without a GOOD solar filter. Doing so can and will cause permanent eye damage. If you do wish to get one, get the type that fits the objective (larger) lens, NOT the eyelens, the eyelens type has a possibility of letting in unwanted direct sunlight.

[deddard]

Nice to see some astronomers here! I haven't been able to do any for a while now (time and being in one of the worst light-polluted places in the country!)

here's a couple of links I came across which may help if you want to check out astrophotography

http://www.astronomy.net/forums/astrophotography/
http://www.cloudynights.com/ubbthreads/postlist.php/Cat/0/Board/Film