More EDA woes. You'd think this was simple stuff.

A project log for Backbone Bus

Backbone is my proposal for an off-chip, Wishbone-inspired backplane interconnect that supports multiple bus masters.

Samuel A. Falvo IISamuel A. Falvo II 06/07/2016 at 17:440 Comments

I'm having a great deal of difficulty resolving one final (known) bug in the PCB layout. And I cannot seem to fix it through any recommended method I know of.

The problem is that the ADJUST pin on the voltage regulator couples into one end of a potentiometer. This should either be pin '1' or pin '3' of the pot. The opposing pin and the wiper pin should be grounded. So, either pins 1 and 2 are grounded, OR, pins 2 and 3 are grounded. Pins 1 and 3 should most definitely not be shorted.

And yet, while this is very clearly expressed in gschem, and the footprint for the pot was redrawn just to make absolutely sure everything is correct, PCB literally insists on shorting pins 1 and 3 of the pot, leaving pin 2 to do whatever it wants.

This is most infuriating, as you can imagine. After spending literally tens of hours trying to debug this, I was left literally screaming at the computer. I can manually route the traces, of course, but the netlist would be completely borked if I do, which renders the "find signal" (F or CTRL-F) function in PCB utterly useless.

I'm at wits end. I don't know what to do.