Replacing switches on a Nexys board

[rain]

I have been asked to change the 8 slide switches on a Nexys board, and I have around 10 boards to complete. Just removing one switch is challenging......would it be any alternative by using the Pmod header interface ? Having Pmod SWT: 4 User Slide Switches x 2 ? and adding Pmod LED ? or do you have any idea ?

[JColvin]

Hi @rain,

I have split your post off into a new topic.

You could just use some sort of external module, be it a Pmod SWT or something else, as a replacement option for the collection of on-board switches, but there are a few catches with this method.

One is that you will inevitably lose out on total available pins that are available to the user. This might not always be an issue if a design doesn't use all of the general purpose input/output pins, but it feels like kicking the problem further down the road.

The second is .xdc file (file that tells the Xilinx software which ports in a design are connected to what physical pin on the FPGA) that Digilent provides will no longer be correct. While you can certainly edit the .xdc file to instead say that all (or just a select few) of the switches are instead attached to some other FPGA pin that goes to a Pmod port (and sets up a good habit of checking and becoming familiar with the .xdc file), this can become a hassle to have to correct every time, especially if the external switches move to different Pmod ports and it is a different collection of switches on the Nexys that are being exchanged out.

It's been a few years since I've had to do any soldering and I wasn't an expert by any stretch of the imagination, so take this next bit with a grain of salt:
I do not know which Nexys board you are using (Nexys A7, Nexys Video, etc.) nor do I know your set up or if you are just replacing the slide switches for different ones or with entirely different I/O devices or whatever, but I would probably look to get some sort of clamp stand (maybe even one designed to hold up an iPad rather than just alligator clips) to hold the board up on its side so that I could heat the underside of the through hole contacts with a soldering iron and pull out the switches with some sort of needle nose pliers.

Let me know if you have any questions.

Thanks,
JColvin