external pin as an input GPIO

[Erick]

Hello,

I am very new to fpgas and vivado but have been playing around with the Arty S7 board for a little while now.  I have used the pushbutton/switches and LED GPIOs pretty easily with the block diagram design and controlling them in SDK.  I am having difficulty figuring out how to use another pin on the S7 board (ie pin L17) as an input.  Do I need to set this up with AXI GPIO, or can I just create an interface port with this pin?  How do I configure this with the constraint file and then ultimately how do I initialize it in SDK?  Thanks for any information.

[JerryG]

You can just create an interface port for that pin. Edit the constraints file for your board and uncomment the line associated with L17 (and optionally rename the signal to something that makes sense to your project).

Most of the Digilent-provided constraints files that I've seen define everything as LVCMOS33, which is fine for your purposes.