Did your "custom board" solution also use 3.3V but "beefed up" the signal line in the same way?
If you need 5V logic, use the 5V board, it'll run faster too.
Did your "custom board" solution also use 3.3V but "beefed up" the signal line in the same way?
If you need 5V logic, use the 5V board, it'll run faster too.