On Wed, Apr 08, 2009 at 07:17:06PM -0500, Bill Gatliff wrote: > > Point is, I can't refute either a 100% success or stay-away-at-all-costs > claim for either device. USB-powered devices in general demand good > decoupling and filtering on VCC, and maybe FTDI-based products that fail > to do that will cause problems. But so would just about everything > else. YMMV.
My main reservation about FTDI is that outside the "USB serial" mode the devices are very focused on write-only behavior. They don't really give you good tools for doing bulk reads. So if you want to pump data INTO a system (eg the common FTDI based JTAG cable) FTDI is a fine choice. If you want to get bulk data OUT it's another thing entirely. In fact, without the Linux drivers I think my project would have failed (turns out the windows drivers actually start a task which periodically flushes the input even if you don't consume it -- the more debug prints I added the worse things got). These days I'd see if I could get a USB AVR to do what I needed. I just used one to make a gamepad (keyboard device) and it was great with the LUFA library. If I needed bigger guns I'd probably use one of the Cypress micros (I think the GNU radio guys use one of those to pump data to/from a Cyclone FPGA). -- Ben Jackson AD7GD <[email protected]> http://www.ben.com/ _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
