Let me ask my question a different way...

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Here's what I need to do, can someone tell me what I should use:

I need to capture a digital image (med - high res color), and send
that image to a remote computer via modem. I know I could do this with
a laptop and other devices, but I need to do it relatively low cost
using an single board computer.

Any suggestions, much appreciated.

Thanks
JS

Re: Let me ask my question a different way...
On 22 Sep 2004 15:22:02 -0700 in comp.arch.embedded, snipped-for-privacy@hmctech.com
(Junior Sanders)

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To provide the best answer to your question, we'll need to know a few more
things.

1. Saying medium to high res color isn't nearly enough information. What are the
dimensions (horizontal, vertical, bits-per-pixel) and frames per second? How are
the
images being captured and how are they being presented to the system? Is the
capturing
device stationary or in motion? How much preprocessing will the system be
expected to
perform?

2. Saying that your device will send images to a remote computer via modem is
also
insufficient. At how many bits-per-second can the modems communicate, will they
be
synchronous or asynchronous, always connected or not? These parameters will give
you a
rough esitmate of the bandwidth you have available. This in turn will tell you,
again
roughly, how long it will take to transmit a single image. If the time is
inadequate, can
you compress the image to reduce transmit time? Do you plan to send images as
they are
acquired or batch them up for mass transmittal? Will the images need to be
time-tagged?

3. You've said nothing about environmental conditions. The requirements for a
rocket-mounted image capture system are quite a bit different from those of a
stationary
hallway monitoring system. What are the ranges of temperature, pressure &
humidity to
which your system may be subjected? How much power is available to your system
(and in
what form)? Is the shape of the system an issue?

4. What is your budget and is the system intended to be a one-time project or a
production
unit? What is the intended lifespan of the system? What MTBF is acceptable?

Answering these questions in greater detail will help you decide how much
processing
power, memory & mass storage (if any) will be required. It will help you
determine what
systems, if any, meet your operational requirements.

I appreciate that you may not want to be too specific about the details of your
project,
but the more information you can share, the more help any answers here are
likely to be.

Let me speculate, given your email address, and say that you are looking for a
system
intended for use inside a manufacturing shop of some sort. Cleanliness will
probably be a
big issue there - the cleanliness of the power getting to your system (shop
power is often
spikey), the cleanliness of the signal between the modems and the cleanliness of
the air
(can you imagine what metallic dust could do if it got inside your computer?) If
this is
meant to be part of a quality & uniformity inspection you'll need real-time
transmittal of
images. This suggests greater need for processing power (because they'll need to
be
packaged and possibly compressed for rapid transmittal) and lesser need for mass
storage
(because once sent, the images can be forgotten.)

good luck

Joe Power


Re: Let me ask my question a different way...
snipped-for-privacy@hmctech.com (Junior Sanders) wrote in message
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Forget about JackRabbit, microcontroller and USB host/bridge adaptor.
None of them give you the resources and low-level access you need.  I
am running a  233MHz Geode GX1 (approx 88 BogusMIPs) with 128M SDRAM
for an USB web-cam.  I am getting 2 to 3 frames (approx. 300x200) per
second without doing anything else.

You need a fast processor to grab the video frames and lock them in
RAM.  Otherwise, you will be losing frames or mixing data from
adjacent frames.  You also need to compress the raw data into jpeg or
mpeg.  The expensive webcams compress the images for you.  The cheaper
ones don't.

On a 900 MHz Celeron with 512M SDRAM, I got about 15 fps.  USB is the
bottle neck here.

You probably need something in-between, perhaps a 500 MHz CPU.  Beyond
that, your CPU is just waiting for the USB.

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Re: Let me ask my question a different way...
snipped-for-privacy@linnix.info-for.us (Linnix) wrote in message
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Ok, let me try to be more specific. The environment will be outdoors.
I can handle this with an enclosure. It will have to run off battery
since there will be no other power available. The device will only
have to take 1 picture and transmit it about every 5 or 10 minutes, so
the connection speed and image size is not that big of an issue. The
image will need to be a jpeg similar to that of a 3 megapixel digital
camera. The device will not have a permanent connection to the remote
computer, it will dial up to the remote computer each time a picture
is taken. Budget is still in the air, I will be producing more than
one of these, so I would like to stay as low cost as possible.

Re: Let me ask my question a different way...

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Run off battery for how long?  IOW, how often do you plan to go out
there and exchange the battery?  Are you aware how hard it is to make
an enclosure that is weather-proof, yet still accessible enough to
allow for regular exchanges of a battery?

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I would advise to re-think that decision.  An analog modem takes on
the order of a minute just to dial and set up a connection.  Doing
that every 5 minutes is quite a waste of time, and possibly also of
money, since you won't be transmitting any payload data during that
time.  On the other hand: if you have a connection to a telephone
line, how come you don't have a connection to a power line?

For most other purposes, you've just described a GSM/GPRS cell-phone
equipped with a camera.  Now all you need is a Java program that tells
it to take a picture and send it, every couple of minutes.  And
somebody rich enough to pay the GPRS service fees for all that.

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

Re: Let me ask my question a different way...
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I hope he meant auto battery, perhaps with a solar charger.  If you
need
5 Watts (such as ours: lower power CPU & Compact Flash Drives), you
need
at least a 15 Watts solar charger (including overnight stand-by).  The
newest solar panels can probably do it in three to four square foot.

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Since it is unlikely to be a digital telephone loop, 33K is the max.
and
takes several miniutes for a typical jpeg image anyway.

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Except that he is not just taking about tiny camera phone quality
(160x140);
not just cheap webcam quality (320x280); not just good webcam quality
(640x480); not just low-end camera quality (800x600); but 3M pixels
high-end camera quality (1200x1000).  It is possible to build such
super camera phone, but we are taking about hundreds, perhaps thousand
dollars each.

Re: Let me ask my question a different way...
snipped-for-privacy@hmctech.com (Junior Sanders) wrote in message
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Well, that would elimate all the webcams and most of the low end
digital
cameras.  I assume that you want a computer controlled digital camera,
not just downloading images.  Only a few high end digital camera would
do so, perhaps two to three hundred dollars each.  Have you selected
the camera?  The camera might be more important than the SBC.  Another
consideration is:  Is your target location secured enough to put in a
three hundred dollar camera?

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Re: Let me ask my question a different way...
On 22 Sep 2004 15:22:02 -0700, snipped-for-privacy@hmctech.com (Junior Sanders)

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Look at http://home.pacific.net.hk/~comedia/mod_JPG.htm for a module
which will give a JPEG image over a serial link. To send it over a
modem a small 8 bit micro will handle this.

Regards
   Anton Erasmus


Re: Let me ask my question a different way...

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Round Solutions have a GSM modem that has a digital camera interface, the
GM-862-PCS.
They sell the camera, connector and GSM/GPRS modem for about EU 115.
Alternately, they have a kit for evaluation of the camera for EU 275

http://www.roundsolutions.com/gsm-modem/index.htm



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