----- Original Message -----
Sent: Thursday, April 17, 2003 10:37 PM
Subject: Re: [M]: Interface cable


> Roger,
>
> Well, that's what I needed to know. I sure wish there was some way to
> [1] speed up the data flow and [2] to let me do imaging from inside a
> warm house without having to try to get a bunch of networking cards
> to hold hands.
>
> Thanks,
> Tom
Getting a 'bunch of networking cards to hold hands', is not that hard!. It
is especially worth realising, that many of the wireless 'access points',
also include a dhcp server, so with the wireless networks, it it often just
a matter of installing the cards, installing the drivers, and telling the
wireless cards at both ends to use the same encryption passwords.
Despite my comments about the two systems using the same channels, I have
had my laptop, controlling my scope, and had a 'virtual PC' program, working
in the house, to access everything, but also had a planetarium program in a
Palm, and used this to actually choose the targets, talking bluetooth to the
laptop, which is also talking 802.11 to the house!...

Best Wishes

> Roger Hamlett wrote:
>
> >----- Original Message -----
> >Sent: Thursday, April 17, 2003 3:43 PM
> >Subject: Re: [M]: Interface cable
> >
> >
> >
> >
> >>Randy,
> >>
> >>There is absolutely no hurry but please do provide that info when it is
> >>convenient. For the record, I do not presently have any bluetooth
> >> equipment but the possibility that a link could eventually added to CCD
> >>cameras is particularly exciting.
> >>
> >>Thanks,
> >>Tom
> >>
> >>
> >Unfortunately, the data rate is not really adequate for this. Think in
terms
> >that with a camera, using say 2M pixels, it'd take 32seconds to transfer
one
> >image (assuming 16bit A-D depth, no compression, and perfect
> >communications). The higher data rates offered by the 802.11 wireless
> >network interfaces, are a more practical proposition (especially with the
> >latest higher rates, 22Mb/sec, and 55Mb/sec). Even assuming you can only
get
> >to perhaps half the theoretical data rate, the time drops to under 3
> >seconds. Rather more practical. The faster Bluetooth specifications, go
to
> >12Mb/sec (not 115200 - the older standard manages 1Mb/sec), which is a
lot
> >more reasonable, but the available performance falls off at longer
ranges.
> >Bluetooth, is perfect for 'control' functions, but not really for the
data
> >rates needed for astronomical imaging.
> >Sadly, the current versions of both Bluetooth, and 802.11, use the same
> >frequency bands, ands the longer range versions, increase the risk of
> >interference (Bluetooth handles this better than 802.11).
> >
> >Best Wishes
> >
> >
> >
> >>Randy Marsden wrote:
> >>
> >>
> >>
> >>>Yet another option is bluetooth. We have recently been using this to
> >>>implement a wireless data link for instruments that my company sells.
> >>>The PC end is as simple as adding a USB/bluetooth module onto a laptop
> >>>or desktop computer and an RS-232/Bluetooth converter at the
instrument.
> >>>The newer and longer range bluetooth module have up to 100 meter (330
> >>>feet) range with very high data reliability at baud rates up to
115,200.
> >>>I imagine that in the near future a bluetooth link could be added to a
> >>>CCD camera allowing a completely wireless connection between the
> >>>computer and the telescope.
> >>>
> >>>If anyone is interested, I can supply manufacturer and model
information
> >>>for these bluetooth modules. I am at home or I would have added it to
> >>>this email.
> >>>
> >>>Randy Marsden
> >>>
> >>>
> >
> >
> >
> >
> >
>
>

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