There is a cable/adaptor for about $40(us) that does it. I have switched to using it to communicate with a PIC based device. Though the throughput is only 19.2K because it runs on some legacy software. The only drawbacks I have seen is that the status lines don't seem to be emulated very well. If you can ignore the status lines and just use TXD and RXD, then this cable/adaptor may be what you want. Its made by (I am not making this up) Bafo. The part number is BF800 or BF810. Hope that helps. Shawn -----Original Message----- From: Andrew Warren [mailto:aiw@CYPRESS.COM] Sent: Tuesday, January 08, 2002 8:56 PM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [EE]:RS232-USB conversion I wrote: > > I'd venture to say that there's no way you'd ever make this work. > > USB is a master/slave protocol, and the cameras are slaves. The > > other side of the interface -- the master -- is hugely complicated > > and could not be implemented in software on a PIC. and Jon Baker replied: > Hmmmmm.. Well.. who's to say that the Camera end has to do anything > other than just convert the usb data into rs232 data and send it over > the radio link. The other end just converts it back again. The media > the data travells through is transparent. "Just" convert the usb data into rs232, then "just" convert it back again, huh? If only it were that simple... > The only reason I can see that it won't work is the speed of the link > ( delay and bandwidth )- the computer will expect the cam to respond > within a given time and may report that the device has been > disconnected if it doesn't respond within that time. You're correct; latency is one reason that it won't work. There are other reasons, too... For starters, full-speed USB runs at 12 Mbps and high-speed USB runs at 480 Mbps. No currently-available PIC will even be able to READ that data, let alone process it. > I don't think powering the device through the usb connector would be a > problem. I concur... But getting data to and from that connector -- especially if you're trying to do it with a PIC or any other general-purpose microcontroller that isn't specifically designed to be a USB host -- WILL be a problem. -Andy (who designs USB microcontrollers for a living) === Andrew Warren -- aiw@cypress.com === Principal Design Engineer === Cypress Semiconductor Corporation === === Opinions expressed above do not === necessarily represent those of === Cypress Semiconductor Corporation -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.