I see that the IceCore bottons are connected directly to port pins. Should a button pin be outputted HIGH to while the button is depressed (by some coding error etc.) then I assume the iCE40HX4K won't like it? I see that since those buttons are shared with a LED, then having a serial resistor is not very feasable.
I am used to adding a serial resistor, so that the button will not take the line fully down, but - like 1/11.
I have 3 external buttons, connected over MX3. I have for a 10k external pullup as well (for less EMC, I have a 433.706 MHz radio just above the unit) and then the button would get the bottom end of a 1k to have to pull to ground. The iCE40 will then see a 1/11 of 3V3 on depressed button.
Is it advisable to add these 1k serial resistors?