I read somewhere that all you need to do is to get the unique ID of the USB device, and then you just use that when communicating.... similar to the MAC or IP address when networking. Like the MAC address of a network card, each USB device has an assigned manufacturer ID followed by more manufacurer specific numbers and then finally some random numbers to make sure there are never (hopefully) duplicate ID numbers.
The one thing you need to address (I believe) is that USB can also provide power (although I do not think cameras use it).
I do not claim to be a USB expert, but this all sounded very logical to me.
Theoretically, the stamp could just send out a certain string of bytes. This would then get the camera to send out it's response. USB is just like broadcast networking. Every device sees all of the traffic, but they only respond when they see their name.
The FTDI USB chip set implements a very nice USB "SLAVE" device. One of the reasons it is so nice is that FDTI has put a LOT of effort into their downloadable drivers, that MUST be resident on the PC. If they are, it works great.
I didn't say Stamps could not USE 'USB'. I said Stamps could not be "USB Master" devices. Thus Stamps cannot be "Master" devices for USB "Slave" devices like USB Cameras. Stamps can certainly be "USB Slave" devices (with the use of the FTDI or similar chip-set). The USB-BOE is a USB "Slave" device.
And by the way, "all you need to do is..." and "you JUST..." and "Theoretically..." are all ways of trying to minimize the effort needed to accomplish something. When you see these phrases in some problem statement, underline them, as they can hide a lot of complexity, making something that can be really hard look trivial.
I don't mean to discourage you here, actually. I'm just trying to explain that USB is NOT "RS-232" (which is fairly simple, actually), that it has a large over-head (in terms of driver development, which you can usually ignore, when using your PC). It is natural for a new person to want to apply this wonderful technology. I just don't want the new people to be mis-lead how difficult this is going to be.
USB is VERY different from RS-232, and even from ethernet-based approaches.
One question:
Is it not possible to just monitor the communication between the PC and the camera, and then try to imitate that with the stamp? (I will take a simple no for an answer here!)
I was going to ask you why YOU don't try to develope a USB interface for the stamp to act as a master, and then get rich selling it us, but I guess that is another thread!!
hahaha!
No problem, I will stick to serial for now, and wait for the USB to come.... it HAS to come some day!!
allanlane5 said...
The FTDI USB chip set implements a very nice USB "SLAVE" device. One of the reasons it is so nice is that FDTI has put a LOT of effort into their downloadable drivers, that MUST be resident on the PC. If they are, it works great.
I didn't say Stamps could not USE 'USB'. I said Stamps could not be "USB Master" devices. Thus Stamps cannot be "Master" devices for USB "Slave" devices like USB Cameras. Stamps can certainly be "USB Slave" devices (with the use of the FTDI or similar chip-set). The USB-BOE is a USB "Slave" device.
And by the way, "all you need to do is..." and "you JUST..." and "Theoretically..." are all ways of trying to minimize the effort needed to accomplish something. When you see these phrases in some problem statement, underline them, as they can hide a lot of complexity, making something that can be really hard look trivial.
I don't mean to discourage you here, actually. I'm just trying to explain that USB is NOT "RS-232" (which is fairly simple, actually), that it has a large over-head (in terms of driver development, which you can usually ignore, when using your PC). It is natural for a new person to want to apply this wonderful technology. I just don't want the new people to be mis-lead how difficult this is going to be.
USB is VERY different from RS-232, and even from ethernet-based approaches.
This article, from Parallax's main website, shows a BS2-controlled camera application.· I think it also lists a few camera models that support this feature.
Comments
The one thing you need to address (I believe) is that USB can also provide power (although I do not think cameras use it).
I do not claim to be a USB expert, but this all sounded very logical to me.
Theoretically, the stamp could just send out a certain string of bytes. This would then get the camera to send out it's response. USB is just like broadcast networking. Every device sees all of the traffic, but they only respond when they see their name.
http://www.parallax.com/html_pages/products/ftdi/ftdi_chips.asp
Again, I am a newbie, so if I am wrong, take it easy on me!!!
Dave
I didn't say Stamps could not USE 'USB'. I said Stamps could not be "USB Master" devices. Thus Stamps cannot be "Master" devices for USB "Slave" devices like USB Cameras. Stamps can certainly be "USB Slave" devices (with the use of the FTDI or similar chip-set). The USB-BOE is a USB "Slave" device.
And by the way, "all you need to do is..." and "you JUST..." and "Theoretically..." are all ways of trying to minimize the effort needed to accomplish something. When you see these phrases in some problem statement, underline them, as they can hide a lot of complexity, making something that can be really hard look trivial.
I don't mean to discourage you here, actually. I'm just trying to explain that USB is NOT "RS-232" (which is fairly simple, actually), that it has a large over-head (in terms of driver development, which you can usually ignore, when using your PC). It is natural for a new person to want to apply this wonderful technology. I just don't want the new people to be mis-lead how difficult this is going to be.
USB is VERY different from RS-232, and even from ethernet-based approaches.
One question:
Is it not possible to just monitor the communication between the PC and the camera, and then try to imitate that with the stamp? (I will take a simple no for an answer here!)
I was going to ask you why YOU don't try to develope a USB interface for the stamp to act as a master, and then get rich selling it us, but I guess that is another thread!!
hahaha!
No problem, I will stick to serial for now, and wait for the USB to come.... it HAS to come some day!!
Dave
http://www.parallax.com/html_pages/resources/custapps/app_aerialphoto.asp
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Chris Savage
Knight Designs
324 West Main Street
P.O. Box 97
Montour Falls, NY 14865
(607) 535-6777
Business Page:·· http://www.knightdesigns.com
Personal Page:··· http://www.lightlink.com/dream/chris
Designs Page:··· http://www.lightlink.com/dream/designs
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Chris Savage
Knight Designs
324 West Main Street
P.O. Box 97
Montour Falls, NY 14865
(607) 535-6777
Business Page:·· http://www.knightdesigns.com
Personal Page:··· http://www.lightlink.com/dream/chris
Designs Page:··· http://www.lightlink.com/dream/designs
·
Not sure why I tyed Eco!!
Thanks!
ECO
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Chris Savage
Knight Designs
324 West Main Street
P.O. Box 97
Montour Falls, NY 14865
(607) 535-6777
Business Page:·· http://www.knightdesigns.com
Personal Page:··· http://www.lightlink.com/dream/chris
Designs Page:··· http://www.lightlink.com/dream/designs
·