Re: Re: Alternative circuit for caller ID converter?

[Stuart Grimshaw <stuart@xxxxxxxxxxxxxxxx>]

On Fri, Apr 16, 2004 at 11:05:54AM -0000, Patrick Lidstone wrote:
> --- In ukha_d@xxxxxxx, Stuart Grimshaw <stuart@s...> wrote:
> > Maxim have the following datasheet for http://pdfserv.maxim-
> ic.com/en/ds/MAX250-MAX251.pdf
> >
> > Does figure3 look like a circuit that could be used instead of
the
> one described on Jon Payne's website?
> >
>
> You don't really need the optoisolated element of this solution. Look
> for a MAX232 data sheet instead.

Are you sure? Isn't it safer to isolate the PC from the other equipment in
this manner?

>
> > My idea is to try and grab the serial data as it's sent to an
> existing LCD, much like the CLID, but instead this is a vending
> machine, I'm fed up trapesing all the way downstairs only to find out
> it's out of coffe/cups/change
> >
>
> Are you sure the data is sent to existing LCD on a serial basis - it
> would be a bit surprising if it was. The caller id hack doesn't
> intercept LCD data, it intercepts what is effectively the modem data
> stream that is the CID data.

Maybe it's sent in serial form somwhere on the way to the LCD, in a similar
way to the caller ID?

>
> You'll probably hate me for saying this, but I reckon you'd be better
> off with an axis-type wireless webcam, zoomed in on the panel. Plus,
> then you can also see if there is a queue :-)

That would be the easy solution, not the UKHA solution :-)


I doubt this will make it past the ideas stage, I bet we rent those
machines, rather than own them so hackery of this kind ist verbotten.

--

-S