Good Day! I need some advice for controlling capturing images from 3 identical cameras one after another in 1 usb plug using a 4 port USB hub. USB port -> 4 port usb hub -> 3 cameras(taking 1 picture at a time) For now, I have already researched on some things, I can use my parallel port to control my usb by using relays: http://ee.cleversoul.com/parallel-port.html can i use this?: http://forums.bit-tech.net/showthread.php?t=101247 Then, do i need to turn on/off my data in each usb plug of the 4 port usb hub? how many realys do i need? Please help, Will
Hmm, I tricky one. i would say you need to write something to send the command to the cameras as individual cameras obviously but I have no clue where to start with this stuff!
which usb hub are you using? one solutions could be to: have all three cameras powered up by the hub. modify the hub so that the d+ and d- cables don't run through the hub, they just "sit there". connect these to a relay (having a regular relay, one in one out, means you would need six relays, one for each cable) which is controlled by the printer/parallell port. you then activate the cameras by writing to the parallell port. for example, the relays are connected like this: relay one and two (camera one) --> pin 2 and 3, relay three and four (camera 2) --> 4 and 5, relay five and six (camera 3) --> pin 6 and 7. this means that to activate camera one, you put 0x381 on the parallell port (1110000001). camera 1 = 0x381 (0b1110000001) camera 2 = 0x261 (0b1001100001) camera 3 = 0x219 (0b1000011001) since the cameras are on constantly you don't need to worry about disconnecting data first and then voltage or vice versa when you're powering up. and i think it eliminates the "new hardware found" thingy in windows (though this could be deactivated in registry). so short answer to how many relays, 6 . (could be three if you get two in two out). (as usual, i'm certainly wrong in more places than one... ... but the friendly people of bit tech will help you out (after biting my head off))
Thank you very much! Im going to try this at once! i'll tell you if it works! im thinking of making a PCB with all the relays and usb sockets/connections I need. This is to prevent me from destroying the hub! all update you soon! thanks!
