On 09/01/2011 10:43 AM, Peter Reilley wrote:
Perhaps another approach might be easier. Use a PC and an A/D
input device. You could create an application that read 2 analog
inputs and displayed them in an X/Y manner in a window. You would
not have to worry about screen resolution. The trick is finding
an A/D input device with at least 2 input channels. I was thinking
an audio input device but I don't think that they handle DC.
Pete.
----- Original Message -----
From: "Kuba Ober"<ober.14@...>
To:<hp_agilent_equipment@...>
Sent: Thursday, September 01, 2011 10:17 AM
Subject: Re: [hp_agilent_equipment] X-Y to VGA/USB converter
Further thoughts: Now I think that the resolution will have to be
adjustable to fit to popular
widescreen LCD monitors. A 1024x768 output does not look too good when
horizontally stretched.
I think the output will have to be matchable to common LCD aspect ratios,
so even if vertically
it's 768, horizontally it may need to be more than that. I think that the
device should read the
DDC information from the monitor and use it for initial setting.
I think that having a DVI output would also be nice, since supposedly
analog inputs on monitors
are going the way of the dodo. DVI shouldn't be an issue since memory
bandwidths to a DAC and to
the DVI are obviously same.
Cheers, Kuba
On Sep 1, 2011, at 10:08 AM, Kuba Ober wrote:
I'm thinking of biting the bullet and making an affordable X-Y-(Z) to
VGA/USB converter for use with various instruments where existing X-Y
displays are dying.
I'm looking for input about the required specs and functionality:
1. Bandwidth
2. Input voltage ranges
3. Required accuracy on voltage-to-coordinate transformation
4. Requirements for sequence triggers to change colors: for example, if a
display
draws some nomenclature, and then goes on to draw traces, it'd be good to
have a way
of setting it up to switch colors automatically on certain events (X,Y in
a certain
area, retrace on X, etc).
5. Other inputs needed for interfacing with particular instruments
6. Resolution: I'm thinking it'd be a 1024x768 24bit framebuffer
7. Persistence adjustments: how many rectangular areas should there be
(upper limit),
each with its own persistence value.
I'm also wondering if there are any spectrum analyzers where display
accuracy would benefit
from taking some IF frequency/ies as the X coordinate instead of a
voltage. Counting frequency
is easy. For my 7L14 I was thinking of using both IFs as the inputs; that
would improve
the accuracy of the display and would make it fixed-frequency.
I don't have any HP SAs or other instruments like that, all I have is a
7L14 spec an.
I'd try to make it as low cost as possible of course, but specs come
first.
Cheers, Kuba Ober
/snip/
Look up Dataq Instruments. Look for model DI-194RS. It has 4 analog input channels.
--doug
--
Blessed are the peacemakers...for they shall be shot at from both sides. --A. M. Greeley
