On 04 Jul, in article <871wt159ha.fsf@localhost.localdomain>
no@spam.thankyou "Ian Braithwaite" wrote:
>paul$@pcserviceselectronics.co.uk (Paul Carpenter) writes:
>> no@spam.thankyou "Ian Braithwaite" wrote:
>>
>> >I'd have thought USB 1.1 was fine for a webcam.
>>
>> I would have thought, by looking at earlier post in the thread, that
>> mentions some figures, it should become clear. USB1/1.1 has a CLOCK
>> rate of approx 12MHz, so you might be lucky and get 2 frames a second
>> (depending on size of image and if camera has compression).
>
>I've seen the Philips 740/840 webcam used with Linux on some mobile robot
>projects with great success.
>With USB1 it manages 5fps at 320x240 uncompressed (that comes to 4.6Mb/s
>data) and 30fps, or 640x480 at 15fps, with the camera's built in compression.
Which exactly echos my point above stated again below
(depending on size of image and if camera has compression).
In my books 320 x 240 is toy vision (and usually very grainy on most cameras)
640 x 480 (as raw size) is the smallest frame size I even consider.
The original poster was trying to achieve 30fps and preferably 640x480.
> no@spam.thankyou "Ian Braithwaite" wrote:
>
> >I'd have thought USB 1.1 was fine for a webcam.
>
> I would have thought, by looking at earlier post in the thread, that
> mentions some figures, it should become clear. USB1/1.1 has a CLOCK
> rate of approx 12MHz, so you might be lucky and get 2 frames a second
> (depending on size of image and if camera has compression).
I've seen the Philips 740/840 webcam used with Linux on some mobile robot
projects with great success.
With USB1 it manages 5fps at 320x240 uncompressed (that comes to 4.6Mb/s
data) and 30fps, or 640x480 at 15fps, with the camera's built in compression.
(http://www.lavrsen.dk/twiki/bin/view/PWC/ApplicationProgrammingInterface
has the full table.)
So it might not be quite as hopeless as you seem to think.
It depends on the application.
Ian
Reply by ●July 4, 20062006-07-04
On 04 Jul, in article <87u05xmaiq.fsf@localhost.localdomain>
no@spam.thankyou "Ian Braithwaite" wrote:
>"linnix" <me@linnix.info-for.us> writes:
>> Ian Braithwaite wrote:
>> > deja@chronofish.com writes
>> >
>> > > It seem I could go several routes. I could go the Linksys route and
>> > > find a WAP for about $30. But I don't know about adding USB ports to
>> > > it.
>> >
>> > Have you looked at OpenWrt? It runs on wireless routers with built in
>> > USB, like the various Asus WL-500...
>>
>> Please correct me if I am wrong about this. The above router, as well
>> as others, has USB 1.0 (<1MB/s) device (not host) and typically less
>> than 50 MHz equivalent mips, less than 4 MB flash and 32MB ram if your
>> are lucky.
>
>The WL-500g has a single USB 1.1.
>The WL-500g Deluxe/Premium have two USB 2.0.
>All the ports are host ports, they tend to be used for things like
>external disks and printers.
Which have extremely slow data rates compared with 15 frames per second
and upwards of cameras. Even webcams doing continuous video.
>I'd have thought USB 1.1 was fine for a webcam.
I would have thought, by looking at earlier post in the thread, that
mentions some figures, it should become clear. USB1/1.1 has a CLOCK
rate of approx 12MHz, so you might be lucky and get 2 frames a second
(depending on size of image and if camera has compression).
>I don't know how much CPU the application would require, you may
>be right that it would be hopelessly underpowered.
> Ian Braithwaite wrote:
> > deja@chronofish.com writes
> >
> > > It seem I could go several routes. I could go the Linksys route and
> > > find a WAP for about $30. But I don't know about adding USB ports to
> > > it.
> >
> > Have you looked at OpenWrt? It runs on wireless routers with built in
> > USB, like the various Asus WL-500...
>
> Please correct me if I am wrong about this. The above router, as well
> as others, has USB 1.0 (<1MB/s) device (not host) and typically less
> than 50 MHz equivalent mips, less than 4 MB flash and 32MB ram if your
> are lucky.
The WL-500g has a single USB 1.1.
The WL-500g Deluxe/Premium have two USB 2.0.
All the ports are host ports, they tend to be used for things like
external disks and printers.
I'd have thought USB 1.1 was fine for a webcam.
I don't know how much CPU the application would require, you may
be right that it would be hopelessly underpowered.
> If you can replace the USB chip with on the go hardware, it would be
> great for transmitting postage stamp sized images.
>
> It would only take a few minutes of research before posting pie in the
> sky proposals.
:-)
Ian
Reply by linnix●July 4, 20062006-07-04
Ian Braithwaite wrote:
> deja@chronofish.com writes
>
> > It seem I could go several routes. I could go the Linksys route and
> > find a WAP for about $30. But I don't know about adding USB ports to
> > it.
>
> Have you looked at OpenWrt? It runs on wireless routers with built in
> USB, like the various Asus WL-500...
Please correct me if I am wrong about this. The above router, as well
as others, has USB 1.0 (<1MB/s) device (not host) and typically less
than 50 MHz equivalent mips, less than 4 MB flash and 32MB ram if your
are lucky.
If you can replace the USB chip with on the go hardware, it would be
great for transmitting postage stamp sized images.
It would only take a few minutes of research before posting pie in the
sky proposals.
Reply by ●July 4, 20062006-07-04
On 3 Jul, in article
<1151987686.620715.174570@v61g2000cwv.googlegroups.com>
deja@chronofish.com wrote:
>Thank you for taking the time to respond.
>
>Paul Carpenter wrote:
>> On 3 Jul, in article
>> <1151948309.418816.240620@v61g2000cwv.googlegroups.com>
>> deja@chronofish.com wrote:
>>
>> >Hello,
>> >What I *think* I want is a single-board computer that:
>> >*Can fit in a 4"x4"x1" space (can be bigger, but not much)
>> >*Has 1-3 USB ports that can handle a web cam, wireless ethernet, and a
>> >USB drive (thumb or SDcard) from which it can boot.
>>
>> Why have wireless ethernet from USB? Sounds like you will need extra
>> drivers and layers of software to gobble up RAM and overhead slowing
>> your system down and making the main board _possibly_ more expensive.
>> Due to extra USB and RAM requirements, when they may well have ethernet
>> ports already and wireless access points are very cheap anyway.
>
>You're right. USB because I knew that many SBC computers have them
>(even my old 133mhz Pentium MMX laptop has a USB port), and I know that
>USB 802.11b/g adapters are small and cheap. Most PC104 boards do have
>ethernet as you indicated - though few (that I've found) are wireless.
>Obviously if I can get it onboard then I would not also need to go
>through the USB port. Seems like even if I go the PCMCIA route that it
>would still require drivers of some sort.
Consider this ethernet port or wireless adapters appear as network adapters
to the OS so the data is sent from/to network card as packets to/from the
network software stack (in simplistic terms).
For USB to wireless/ethernet adapters the data is sent from/to the network
stack to/from a pseudo network driver, that then encapsulates the data
to send to the USB controller driver (under the same OS) to send to the
USB device to de-encapsulate the network traffic to send to/from the
wireless/ethernet.
The extra hoops and encapsulation steps (let alone doing any compression)
puts extra load on the cpu and RAM requirements, which in turn limits your
dataflow. Also more layers of software/drivers to go wrong, be incompatible
and other such problems.
Even a PCMCIA wireless card is closer to a network card than a USB device.
>> >*Preferrably is compatible with the x86 architecture
>> >*Would like to have a parallel printer port
>> >*Has sufficient Memory - (Not really sure at this point : enough to run
>> >apache/php in addition to the OS (Linux))
>> >*Speed-(Not really sure - see "the jist of it")
>> >*Is Cheap (less than $100 - preferably less than $50)
>>
>> Considering your requirements and later items I doubt you will get
>> near this price.
>
>About the best I've found so far is $69 for a new PC104. I could go
>that high. I'm also contemplating an HP 720LX handheld which are going
>for about $35 in a "used" condition.
I would still suggest using a dedciated USB web cam server plus wireless
access point and a LARGE battery.
e.g. <http://www.digidave.co.uk/product_info.php?products_id=254>
Plug your USB 2.0 camera into the server, test with wired ethernet first.
(this unit can take TWO webcams).
The server is a small box that costs about 80.00 UK pounds!
If you were willing to replace the camera there are webcams like ones
reviewed here that are webcams to 802.11g in one unit around 100 UK pounds
already.
<http://www.filesaveas.com/wifiwebcam.html?gclid=CLmBgLH194UCFSFsEAodyXIjuA>
Even the Dlink wifi camera DCS-5300W can be got for around 70 UK pounds.
That is your camera and most of your system.
Alternatively look at
<http://www.x10.com/key_products/wireless-webcam.htm>
This is wireless but to a TV not the web.
Looking at wireless CCTV that gives a receiver and TV output such as
<http://www.y3kvision.com/acatalog/3k15.html>
About 50 UK pounds including camera and receiver.
These from simple google searches for 'webcam server' or 'wireless
webcam server'.
>> >I don't need keyboard input, video, or HD/FD controllers
>> >
>> >The jist of it:
>> >I would like to be able to run a wireless webserver that can serve up
>> >web-cam pictures at 30fps.
>>
>> Have you done the calculations for how much data just the 30fps at
>> whatever resolution you are choosing will be?
>>
>> Have you even worked out what picture resolution you need or want?
>>
>> I doubt it to BOTH of the above questions!
>
>You're right. Maybe 30fps is a bit optimistic. I will have to think
>about that some more. I think the standard web-cam does 320x240 and
>640x480 for "hi rez". Maybe 15fps at the lower res will be palletable
>(I'll have to experiment).
This information determines your system requirements, and requirements
for the parts of the system (camera, wireless end, what processing e.g.
compression, etc.).
>> You have to get this data at 30fps from the camera via USB to your
>> very cheap system, then out again over the same USB controller
>> to a USB to wireless.
>>
>> Work out how much data continuous video is and whether you have the
>> available bandwidth in BITS per second to achieve your requirements
>> bearing in mind the overheads of USB and Wireless AND ethernet.
>>
>> What is it with people that think USB is cheap therefore it is
>> the answer to EVERYTHING!
>
>Because when you don't have a lot of cash to blow you don't have a lot
>of choices. In my case I'm trying to stick with what I've got laying
>around the house. It doesn't need to be perfect or pretty. Even if I
>get this project to simply limp around I will consider a great
>accomplishment. How's that for setting the bar high.
It is fine to use what you have if it is capable of doing what you need.
"If all you have is a hammer, everything looks like a nail".
>> >The parallel port is not for printing but for throwing switches. I
>> >supose this could be done through a USB/serial port, but I am not much
>> >of a hard-ware guy, so I don't want to mess with programming a PIC to
>> >translate a serial command to throw a switch.
I would actually say whatever you do you will _probably_ need to write some
software and depending on how the 'throw a switch' translates into hardware
interfacing could be an issue in creating interface hardware. If nothing
else to take some commands from a web form to execute a CGI programme
to then access the parallel port. This turn will need hardware to interface
to your 'switches' whatever they may be.
No 'solutions' I have seen do both video transmission and control up stream
except to control specific pan/tilt/zoom camera protocols. These are usually
specific to each camera.
I would look at telemetry devices and see if you can find a telemetry device
that works one way on a different frequency to send a serial byte to a
telemetry device with parallel o/p. I am sure they exist and relatively
cheaply.
It all depends on what the 'throw a switch' means as in how many, what the
'switch' is controlling in terms of load voltage/currents etc..
>> >It seem I could go several routes. I could go the Linksys route and
>> >find a WAP for about $30. But I don't know about adding USB ports to
>> >it. Or I could go the "broken" laptop route and shove the guts into my
>> >box. But maybe someone from this group could suggest a SBC that will
>> >do what I'm looking for.
>>
>> Possibly see if you can just simply find an ethernet or wireless webcam
>> that already exist!
>>
>> Ethernet cameras ALREADY exist!
>>
>> Wireless cameras (many NOT using wireless ethernet) ALREADY exist!
>
>Yes but I have a USB web cam.
Which may be part of the problem, I know you have it but it may be easier
cheaper (in money and time) and much quicker to use a better tool.
>> This data is being sent to some central point (no doubt to connect to
>> internet for a school project), which will have all the grunt power
>> required and more capability to run things like apache/php EASILY.
>
>Ah... That's where you're wrong (with all due respect). This project
>IS the central point. I can see why you think I'm a student (due to
>your preceived short-comings of me)
Hmm this may be central point but I assume the wireless is connecting
to something. If you don't need this accessible via the internet I would
still consider the wireless CCTV to a TV/VCR option. Unless you need to have
the video on another PC for other reasons.
The main thing that made it look like a school project is the method
and requirements. Too often I see
must have x86
must use a cheap web cam
must have wireless
The standard ingredients of a school project.
> - but no - I am just a software
>developer who was fortunate enough to find a really cool robot platform
>at a garage sale for $2, and who is helping out at "robot camp" in
>about two months (two of my nephew's are visiting grandma for "robot
>week"). We have a couple of old radio shack "Arm-a-trons" and small
>"robot" kits for them to build - as well as the obligatory showing of
>the animated "Robots" etc. For a 7 and 10 year old (and my 1 month
>old) it should be quite fun even if this particular project doesn't get
>very far.
I would suggest that getting a bought in solution would be quicker, easier
and lighter to power (smaller batteries).
The quicker solution may get more interest from the children.
>> You have taken the requirements the WRONG way round and started with
>> x86 and USB then tried to shoehorn what you want to do into it. In reality
>> shoehorn a fast desktop into a cigarette box!
>
>Well - yeah. I have some basic needs and a small space and limited
>time to learn a bunch of new stuff. By the way, I started by
>"shoehorning" an old desktop but there just wasn't enough space - and
>then of course the power requirements.....
>
>
>Thanks again - you didn't really give me the answer I was looking for,
>but it did inspire me to keep moving and not wait for the perfect
>answer.
> It seem I could go several routes. I could go the Linksys route and
> find a WAP for about $30. But I don't know about adding USB ports to
> it.
Have you looked at OpenWrt? It runs on wireless routers with built in
USB, like the various Asus WL-500...
Ian
Reply by ●July 4, 20062006-07-04
Thank you for taking the time to respond.
Paul Carpenter wrote:
> On 3 Jul, in article
> <1151948309.418816.240620@v61g2000cwv.googlegroups.com>
> deja@chronofish.com wrote:
>
> >Hello,
> >What I *think* I want is a single-board computer that:
> >*Can fit in a 4"x4"x1" space (can be bigger, but not much)
> >*Has 1-3 USB ports that can handle a web cam, wireless ethernet, and a
> >USB drive (thumb or SDcard) from which it can boot.
>
> Why have wireless ethernet from USB? Sounds like you will need extra
> drivers and layers of software to gobble up RAM and overhead slowing
> your system down and making the main board _possibly_ more expensive.
> Due to extra USB and RAM requirements, when they may well have ethernet
> ports already and wireless access points are very cheap anyway.
You're right. USB because I knew that many SBC computers have them
(even my old 133mhz Pentium MMX laptop has a USB port), and I know that
USB 802.11b/g adapters are small and cheap. Most PC104 boards do have
ethernet as you indicated - though few (that I've found) are wireless.
Obviously if I can get it onboard then I would not also need to go
through the USB port. Seems like even if I go the PCMCIA route that it
would still require drivers of some sort.
>
> >*Preferrably is compatible with the x86 architecture
> >*Would like to have a parallel printer port
> >*Has sufficient Memory - (Not really sure at this point : enough to run
> >apache/php in addition to the OS (Linux))
> >*Speed-(Not really sure - see "the jist of it")
> >*Is Cheap (less than $100 - preferably less than $50)
>
> Considering your requirements and later items I doubt you will get
> near this price.
About the best I've found so far is $69 for a new PC104. I could go
that high. I'm also contemplating an HP 720LX handheld which are going
for about $35 in a "used" condition.
>
> >I don't need keyboard input, video, or HD/FD controllers
> >
> >The jist of it:
> >I would like to be able to run a wireless webserver that can serve up
> >web-cam pictures at 30fps.
>
> Have you done the calculations for how much data just the 30fps at
> whatever resolution you are choosing will be?
>
> Have you even worked out what picture resolution you need or want?
>
> I doubt it to BOTH of the above questions!
You're right. Maybe 30fps is a bit optimistic. I will have to think
about that some more. I think the standard web-cam does 320x240 and
640x480 for "hi rez". Maybe 15fps at the lower res will be palletable
(I'll have to experiment).
>
> You have to get this data at 30fps from the camera via USB to your
> very cheap system, then out again over the same USB controller
> to a USB to wireless.
>
> Work out how much data continuous video is and whether you have the
> available bandwidth in BITS per second to achieve your requirements
> bearing in mind the overheads of USB and Wireless AND ethernet.
>
> What is it with people that think USB is cheap therefore it is
> the answer to EVERYTHING!
Because when you don't have a lot of cash to blow you don't have a lot
of choices. In my case I'm trying to stick with what I've got laying
around the house. It doesn't need to be perfect or pretty. Even if I
get this project to simply limp around I will consider a great
accomplishment. How's that for setting the bar high.
>
> >The parallel port is not for printing but for throwing switches. I
> >supose this could be done through a USB/serial port, but I am not much
> >of a hard-ware guy, so I don't want to mess with programming a PIC to
> >translate a serial command to throw a switch.
> >
> >
> >It seem I could go several routes. I could go the Linksys route and
> >find a WAP for about $30. But I don't know about adding USB ports to
> >it. Or I could go the "broken" laptop route and shove the guts into my
> >box. But maybe someone from this group could suggest a SBC that will
> >do what I'm looking for.
>
> Possibly see if you can just simply find an ethernet or wireless webcam
> that already exist!
>
> Ethernet cameras ALREADY exist!
>
> Wireless cameras (many NOT using wireless ethernet) ALREADY exist!
Yes but I have a USB web cam.
>
> This data is being sent to some central point (no doubt to connect to
> internet for a school project), which will have all the grunt power
> required and more capability to run things like apache/php EASILY.
Ah... That's where you're wrong (with all due respect). This project
IS the central point. I can see why you think I'm a student (due to
your preceived short-comings of me) - but no - I am just a software
developer who was fortunate enough to find a really cool robot platform
at a garage sale for $2, and who is helping out at "robot camp" in
about two months (two of my nephew's are visiting grandma for "robot
week"). We have a couple of old radio shack "Arm-a-trons" and small
"robot" kits for them to build - as well as the obligatory showing of
the animated "Robots" etc. For a 7 and 10 year old (and my 1 month
old) it should be quite fun even if this particular project doesn't get
very far.
>
> Considering the nature of most USB controllers, it takes a lot of the
> system resources to get 30fps VGA (640x480) in on USB 2.0, so I doubt
> you will have enough system speed or resources left to also send out
> over USB to wireless ethernet. Especially on a small SBC with limited RAM
> and USUALLY much SLOWER than desktop PC x86.
You've made your point. I've decided that I'll take my old laptop and
get things "working" as best I can. Maybe I'll just have to re-think
the size/mounting aspect I suppse the robot can wear a back-pack with
the laptop in it. Won't be as polished but given the time/money
constraints...
>
> You have taken the requirements the WRONG way round and started with
> x86 and USB then tried to shoehorn what you want to do into it. In reality
> shoehorn a fast desktop into a cigarette box!
Well - yeah. I have some basic needs and a small space and limited
time to learn a bunch of new stuff. By the way, I started by
"shoehorning" an old desktop but there just wasn't enough space - and
then of course the power requirements.....
Thanks again - you didn't really give me the answer I was looking for,
but it did inspire me to keep moving and not wait for the perfect
answer.
-CF
> deja@chronofish.com wrote:
> >What I *think* I want is a single-board computer that:
> >*Can fit in a 4"x4"x1" space (can be bigger, but not much)
$ = k * 1 / sq(")
> >*Has 1-3 USB ports that can handle a web cam, wireless ethernet, and a
> >USB drive (thumb or SDcard) from which it can boot.
Just get a 500MHz laptop, but USB bootable laptop don't comes in such
slow system.
> >*Preferrably is compatible with the x86 architecture
> >*Would like to have a parallel printer port
> >*Has sufficient Memory - (Not really sure at this point : enough to run
> >apache/php in addition to the OS (Linux))
> >*Speed-(Not really sure - see "the jist of it")
> >*Is Cheap (less than $100 - preferably less than $50)
Probably $200 to $300, usually $500 to $600 for USB bootable.
> Have you done the calculations for how much data just the 30fps at
> whatever resolution you are choosing will be?
Approx. 30MB/s raw YUV or 5 to 10 MB/s jpeg. USB can transfer roughly
3 to 4 MB/s. So, you need 2 chanels in and 2 channels out for jpeg.
Not all webcam can provide jpeg directly, so your "cheap" sbc would
have to do the compressions.
> What is it with people that think USB is cheap therefore it is
> the answer to EVERYTHING!
Blame the marketing people, we, the consumers are dumb.
> >It seem I could go several routes. I could go the Linksys route and
> >find a WAP for about $30. But I don't know about adding USB ports to
> >it.
Add a PCI to USB bridge, but you might have to replace the CPU with one
having PCI first.
Reply by ●July 3, 20062006-07-03
On 3 Jul, in article
<1151948309.418816.240620@v61g2000cwv.googlegroups.com>
deja@chronofish.com wrote:
>Hello,
>
>I've been googling for a couple days now and am now looking for
>suggestions.
>
>What I *think* I want is a single-board computer that:
>*Can fit in a 4"x4"x1" space (can be bigger, but not much)
>*Has 1-3 USB ports that can handle a web cam, wireless ethernet, and a
>USB drive (thumb or SDcard) from which it can boot.
Why have wireless ethernet from USB? Sounds like you will need extra
drivers and layers of software to gobble up RAM and overhead slowing
your system down and making the main board _possibly_ more expensive.
Due to extra USB and RAM requirements, when they may well have ethernet
ports already and wireless access points are very cheap anyway.
>*Preferrably is compatible with the x86 architecture
>*Would like to have a parallel printer port
>*Has sufficient Memory - (Not really sure at this point : enough to run
>apache/php in addition to the OS (Linux))
>*Speed-(Not really sure - see "the jist of it")
>*Is Cheap (less than $100 - preferably less than $50)
Considering your requirements and later items I doubt you will get
near this price.
>I don't need keyboard input, video, or HD/FD controllers
>
>The jist of it:
>I would like to be able to run a wireless webserver that can serve up
>web-cam pictures at 30fps.
Have you done the calculations for how much data just the 30fps at
whatever resolution you are choosing will be?
Have you even worked out what picture resolution you need or want?
I doubt it to BOTH of the above questions!
You have to get this data at 30fps from the camera via USB to your
very cheap system, then out again over the same USB controller
to a USB to wireless.
Work out how much data continuous video is and whether you have the
available bandwidth in BITS per second to achieve your requirements
bearing in mind the overheads of USB and Wireless AND ethernet.
What is it with people that think USB is cheap therefore it is
the answer to EVERYTHING!
>The parallel port is not for printing but for throwing switches. I
>supose this could be done through a USB/serial port, but I am not much
>of a hard-ware guy, so I don't want to mess with programming a PIC to
>translate a serial command to throw a switch.
>
>
>It seem I could go several routes. I could go the Linksys route and
>find a WAP for about $30. But I don't know about adding USB ports to
>it. Or I could go the "broken" laptop route and shove the guts into my
>box. But maybe someone from this group could suggest a SBC that will
>do what I'm looking for.
Possibly see if you can just simply find an ethernet or wireless webcam
that already exist!
Ethernet cameras ALREADY exist!
Wireless cameras (many NOT using wireless ethernet) ALREADY exist!
This data is being sent to some central point (no doubt to connect to
internet for a school project), which will have all the grunt power
required and more capability to run things like apache/php EASILY.
Considering the nature of most USB controllers, it takes a lot of the
system resources to get 30fps VGA (640x480) in on USB 2.0, so I doubt
you will have enough system speed or resources left to also send out
over USB to wireless ethernet. Especially on a small SBC with limited RAM
and USUALLY much SLOWER than desktop PC x86.
You have taken the requirements the WRONG way round and started with
x86 and USB then tried to shoehorn what you want to do into it. In reality
shoehorn a fast desktop into a cigarette box!
--
Paul Carpenter | paul@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/> PC Services
<http://www.gnuh8.org.uk/> GNU H8 & mailing list info
<http://www.badweb.org.uk/> For those web sites you hate