Hi Gene,
Opto stuff, with their speed limits, are much more trouble than they're worth, I've cut many of them out of bobs. A limiting resistor and a schotkey diode to each rail s/b be input protection limit enough.
I have to disagree. Unless you need high speed, such as for encoders, optos are very worthwhile. Their slow speed helps mask out any short duration noise on the line. The isolation is also good for reducing noise.
And yes, I'd be interested in something that I could run thru pcb2gcode and make myself, and I suspect I am not alone.
The layout is pretty tight for mechanical etching. If I remember correctly some track gaps are only 0.006". Making the board very configurable had the down side of also making it pretty tight in places. It's a 100mm x 100mm board and some Chinese PCB manufacturers are offering crazy low prices to build this size board. I used to make my own boards but these days it is so cheap to get them made it is not worth the effort. I've found the Chinese made boards to be very good quality. I just checked on pcbshopper.com and you can get 5 delivered to your door for a total of $8.33 in 23 days or if you are in more of a hurry how about $13.38 in 16 days?
I've even done the drill holes at only 40 thou into the board from each side and made them meet in the middle of the board. And I've got lots of board. The 7i90HD is a good start on a do anything board, but it sure needs protection, its very easily damaged by stray noise.
I've used quite a few of the Mesa FPGA boards and I've only ever killed one - that was by feeding 24V back down one of the outputs. Maybe you should consider using optos ;-)
Les _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
