Re: gEDA-user: terminators
DJ - Before you create another board, could you try using a razor to cut all the logic analyzer traces right near or at the vias? This may help, and if the board doesn't work now, there is no harm in a minute with the knife. I've laid out an interface to a 133Mhz SDRAM, and the path lengths were similar to yours. Works great. No LA connector, though. Tim On Mon, Apr 6, 2009 at 10:35 PM, DJ Delorie wrote: > >> Hey Steven, that's a pretty interesting analysis. I just want to add >> something from Dr. Howard Johnson's book on this stuff. His claim is >> that you can treat a pcb trace as a lumped system if the trace is less >> than 1/4 * 'length of the edge'. Well, at 170 ps/inch the length of the >> edge is about 5.8" - that's exactly 1/2 your result. > > If I remove the LA connector and shove the sdram closer to the fpga, I > get a trace length range of 2027 mils (CLK) down to 281 mils (DQ7), a > mis-match of 1.7 inches, or just under 1/3 of 5.8". > > I wonder if I could drive the shorter traces less than the longer > ones, to match up the edges at the sdram? > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: fyi: program to enter spreadsheet contents into a Digi-Key web-order
DJ, Wow, i *really* wish that I had known that earlier. No need for some script if you can just upload the file directly... indeed, i should have guessed that such functionality existed! I guess all is not lost, though, as now we have some way of programmatically interacting with the digikey website. maybe in the future I'll use it to sort available parts by *price*. (e.g. something to automate selection of surface mount resistors and capacitors, which i find tedious). Maybe even with a UI or something. thanks, Tim On Fri, Feb 13, 2009 at 6:05 PM, DJ Delorie wrote: > > You know, you can just upload a CSV spreadsheet to Digikey's master > ordering module. My BOM scripts export the .csv file, I just send it > to them and it orders everything on the list. > > I don't know how (or if) you'd do it without logging in, but when you > do log in, just use "Order File Upload". > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: fyi: program to enter spreadsheet contents into a Digi-Key web-order
Hi All, I wrote this script yesterday as I needed to enter ~200 parts into Digikey, and didn't want to make any mistakes. It reads in a CSV file, establishes a TCP connection with the Digikey ordering web server, and repeatedly POSTs the quantities in your spreadsheet onto the active server pages. If the minimum quantities are not met for any of your items, it will first guess the next multiple of 10, and if that does not work, it will ask you for the quantity. Digikey's webserver occasionally balks under the torrent of POST and GETs, in which case you'll have to kill the script, start a new web order, and try again. hope this is useful to someone other than myself. Tim -- source: http://code.google.com/p/kicadocaml/source/browse/trunk/scripts/digikeyweborder.ml makefile: http://code.google.com/p/kicadocaml/source/browse/trunk/scripts/Makefile readme: http://code.google.com/p/kicadocaml/source/browse/trunk/scripts/README ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
