As the title says; are there any herder pins that are attached to the FPGA? Do I have to get a pci express socket and use one of those pins? I just need two digital signal inputs...
And, if there are, how do I pick those to associate in Quartus? I have this FPGA_interface demo project that I've added some things to; it references PIN A0,A1,A2 but those always come back with a status of 1 - but then the default in the board layout is VCC so I suppose I should expect that - but I tried to attach those to ground to pull them down, and had no change in the FPGA... I had assumed that I could just A3 and A4, and got no errors, but then triggering those doesn't work.
At this time I'd like to just take an arduino Uno that blinks its LED every so often and attach that to an input to the FPGA to test with.
Did you check with schematics? All of the header pins are connected to both SAMD and FPGA. So if you want to drive some pin with FPGA, then do not attempt to drive same pin with MCU.
The A0, A1, D0, D1 references - those are the numbering within Arduino ecosystem, they're remapped into MCU pins using definitions in .h files for a specific MCU and/or the board within Arduino setup for C/C++ compilation.
But when you're building your own FPGA design in HDL - always check with the schematic. For example, the D3 arduino header pin is connected to port PA11 on MCU and to pin R3 on FPGA. When driving the pin from FPGA side you assign R3 as pin for that signal, and you avoid driving that pin from the MCU. You still might read it on both devices, or you can make some elaborate scheme that will allow MCU or FPGA drive the same pin for outputs, just one side at any given moment.
Okay I did try to track down the schematic, but it sent me to a 1000 board. https://docs.arduino.cc/hardware/mkr-vidor-4000 This has a pinout
and the link to get started only has a link back to the same page
Arduino page design seems not as intuitive as it was before...
You found the right page about the board (https://docs.arduino.cc/hardware/mkr-vidor-4000), and the schematic is aaaall the way down, in the "Resources" section, Downloads sub-section.
There is a Full pinout doc, and the Schematics. It's right above the "Troubleshooting" section.