Would Like To Control My Scope With A Laptop ...

[Vortex]

Hi,

Not sure if this question has been asked before, however being a bit of a newbie ....

The ultimate aim of my project is to be able to have my scope set up outside as normal, but to be able to sit in my house and control the scope from my laptop and be able to take video images of what I see. I have the modded Phillips SPC800NC webcam.

Being a Microsoft Engineer the laptop/software side of things doesn't pose a real problem for me, however only beginning to get into amatuer astronomy my scope is currently very basic (Skywatcher 130 M).  Due to costs, I was looking at a EQ3-2 Deluxe Goto Synscan mount to put my scope on, but not sure if this would have the PC connections necessary to be able to control the scope from ?  Ideally would like a HEQ5 mount, but cannot run to that currently.  Alternatively I understand that some of the Celestron mounts have a nice convenient power plug that can be purchased and plugged into the mains used to power them - so saving costs on a power tank.

What would be any advice that you could give ?  How do you currently control your scope remotely whilst sitting in the warmth of your home?   (I know - what a wimp eh ?)

Any advice gratefully received - many thanks

[malc-c]

Its hard to answer your question as you need to give us some indication of how remote "remote" is.  If you plan on having the scope less than 5m away from your PC in the lounge then you could run active USB cable for camera, and a long serial lead for the sysmscan connection.  If on the other hand you want to set up at one end of the garden and the house is 30m or so away then you'll need a small netbook / laptop setup and RDC into it.  Most of us with observatories use this method.

A typical set up would be:

• PC, laptop or netbook running EQMOD scope control, CdC planetarium software, sharpcap for your webcam.
• Direct connection to the mount via an EQDirect cable (can be DIY or purchased for around £50)
• Powertank or suitable low voltage mains supply (main supply housed in a shed or outbuilding and the low voltage run to the scope)

The computer would need to have network connectivity so you can RDC to it

As for the connection between the PC and the mount, there are two ways to do this with SW goto mounts.

• Make or purchase an EQDirec cable.  This is basically an RS232 5vTTL USB cable (most of us use an FTDI 232TTL5V cable spliced to a cat 5 cable - or you could crimp the RJ plug directly on the end - )  this plugs direct into the same socket as the handset - so you don't need the handset connected.
• Purchase the serial PC lead for a SW scope - around £15 for 5m - and a USB to serial adaptor (assuming the PC has no serial port) and connect this to the handset and place the handset into PC-DIRECT mode.

Hope that helps -

[Squagnut]

If you're thinking primarily of imaging with a webcam then you don't *need* an equatorial mount - you may *prefer* one, but I don't see that it will bring any significant advantage. A SynScan AZ alt-az mount, which can easily be connected to a PC, would be fine and should be able to take the weight of your OTA. EQMOD is very useful and powerful, but it doesn't work either on alt-az mounts or on Celestron equatorial mounts.

As Malc said, how you connect PC to mount depends on distance. I'd use a powered USB hub at the far end of a 10m extension cable, and connect both webcam and mount to it. Further than that and I'd look at wireless options.

If your laptop output is a USB port, you'll need a USB-serial adapter. These are cheap and easy to find.

You might also like to consider focusing. Popping out and in to get your webcam is in focus would be annoying! There are ways of remotely controlling focus too, but practical astronomy is often about doing legwork to make the most of the kit you have.

[Vortex]

Thank you Malcom and Phil for taking the time to post your detailed replies - it is very useful information and very much appreciated