GPUSB

[DIYASTRO]

Has anyone tryed to use the GPUSB shoestring adapter for an opto isolater relay switing circuit, if so I would like to hear from you. I want to use the GPUSB as a multi function motor drive via relays to opperate focus and filter wheels etc.

CAN ANYONE HELP?

[Dave Moulton]

I've got one of these little beauties but never tried to make it do anything other than what it is intended for.

I would be guessing that the unit has a common and four zero volt opto isolated switches to input guide corrections for the motors. Would you need two for the focusser forward & reverse. Not sure how many you would need for the wheel another two probably so sounds feasable to me, interesting stuff.

I seem to remember that there was a software simulator available from shoestring as a freebie for the GPUSB to test each motion. May be a good way of interpreting the wiring outputs from the GPUSB box. You could even use it I guess to control focus and the wheel once you have hosed up the wiring

Dave

[Dave Moulton]

A couple of shoestring links for you

http://www.store.shoestringastronomy.com/guide_port_cables.pdf

http://www.store.shoestringastronomy.com/downloads.htm

Good Luck,

Dave

[DIYASTRO]

Thanks Dave,

I have the links that you quote and have looked at various other links which I dont trust too much. You are correct in that the 6 pins has one N/C the others are just what you anticipate except like me you suspect that a common ground would be normal! From what I can see so far its the reverse in that we have a common positive and 4 negative outputs that seem to be low until we opperate the desired function via the software that you mentioned which is the GPUSB check.

It should be possible to make up a small relay board with opto isolators for protection against feedback so that you would be able to do all manner of things eg operate camera shutters filter wheels focus devices you name it. Will let you know how I get on. Thanks

[Psychobilly]

if your up for a bit of programming then this is quite a nifty little kit...

http://www.maplin.co.uk/Module.aspx?ModuleNo=42857

Billy...

[DIYASTRO]

I have seen this bit of kit Billy, ands thanks for the link.

My problem is time and I dont have enough for prog. with pc each time I want to change application. I also like to put all my equipment through its paces and get as much from what I have as possible, I would like another GPUSB though if anyone has one that they dont need!

[Psychobilly]

Im wondering is you can run 2 GPUSB's ont he pc at the same time....if the software supports multiple instances...would be good to try before you buy...

I know for their focus contol product they have a "1" and "2" which are identical excpet they have different USB identifiers so that you can use 2 on the pc at the same time - one for main and one for guidescope for example

Billy...

[DIYASTRO]

Billy, interesting that, I have this problem on an intermitent basis with webcams in particular spc900nc so I have now got two dedicated del pc's to seperate any system that I wish to run that can produce the recognition problems that you point out. I also could not get along with my guiding camera and imaging system on the same screen or pc which tends to slow everything down.

So if you know anyone who has a GPUSB going cheap let me know?

[Psychobilly]

Every time you plug a usb device into a differnt port ot onto the end of an active extension lead or hub etc it creates a new instnce of the device which is what can lead to the confusion.

If you look in device manager you will only normally see active decives - ones actually connected at the time there are a couple of command line switches that allow you to see al instances of the devices and have a clear out...

this text comes from here

http://www.starrynightsupport.com/support_trio/index.php?action=kb&article=201

its about com ports but the same technique can be used for any "device" category at oen point I thinkj I had 11 instnces of a Meade DSI and dimilar for my SPC900 as i had been movign them around ports on a hub and the hub around different ports on the laptop...

1. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.

2. At a command prompt, type the following command , and then press ENTER:

set devmgr_show_nonpresent_devices=1

3. Type the following command at command prompt, and then press ENTER:

start devmgmt.msc

4. Click View > Show hidden devices. This will display devices that are not connected to your computer but Windows XP still reserves space for them.

5. expand the section that the device your havign problems with is in.

6. remove the instances of the device...

Reconnect devices... and hopefully everything should be ok...

I know have all the ports labelled so I connect the same usb devices to the same place every time.

Billy...

[DIYASTRO]

Billy,

I shall most certainly try this when I get the chance. In practical terms I think that the best bit of pc management advice I have had in a long long time! Thanks