Some kind of way of gating the SPI lines based on the GO signal, similarly to the SN74AC245N used in the CPU card
It should have some kind of jumper, switch, or solder bridge to select which GO signal it listens to
Optional: It would be nice to have a low profile Featherwing socket as well
By default, the "MISO", "MOSI" ("CIPO" and "COPI") and "SCK" lines from the feather footprint should be used for the SPI connections.
Connection from the Bus 3.3v pin and the Feather 3.3v pin should be jumpered or solder bridged (in case 5v power is used)
There should be a weak (10k?) pullup on the OE/GO line
If using an SN74AC245N, unused INPUT pins should be pulled in a consistent direction
Pin headers should be provided for SWD lines, as these will probably require fly-wires from the feather itself
Pins not used for the Anachro connections should have some kind of header available for use
Edit:
I wanted to add a couple notes.
I'd like to be able to order these boards relatively cheaply through a service like JLCPCB or OshPark
I'd like these boards to be mostly through-hole compatible, so that they are easily solderable as kits, OR to be orderable fully populated (e.g. with JLCPCB's assembly service)
I am willing to fund the first couple hardware spins (PCBs, Components) for this. Please get confirmation from me directly BEFORE ORDERING if you would like me to pay for this or reimburse you.
I am looking for assistance in designing a PCBA that is compatible with the Stargazer Backplane, a 40 pin, 0.1" header.
Design notes:
Edit:
I wanted to add a couple notes.