for some reason i ended up with a bunch of bare FTDI pcbs - most people buy them as preassembled cables - and every time i need to talk to an AVR or similar device, i end up needing to build myself a new cable assembly.

at my last job, i systematized this pretty well (over the period of nine months or so), but the pinout (among other things) on an Arduino Fio, which is what i'm using for a current project, is different than the custom PCBs we had Todd Bailey make for that project.

so i've got this fucked-up workflow where i need to find the datasheet for these FTDI chips, then find the page where the pads are labeled, then figure out which pads need to be connected to which locations on the device, then solder the whole thing up - which is tricky, cause they're pads instead of thru-holes - and then test the assembly. about two thirds of the time i get it wrong, and need to troubleshoot the whole thing once or twice before it works right. but my documentation is getting better, if only slightly.

anyway, as a public service: the diagram below works. if you're working with a Fio, you can only program it (non-wirelessly) with an FTDI chip, and if you're sitting on a bunch of unassembled chips... well, then, this might be useful to you.

now, i've just got to get it programming wirelessly :/