I am looking at putting the Spark module into a product. There are two things that I need to do this. The first is a Light Pipe so I can see the LED from the case. The other is the ability to have an external MODE button. The light pipe should be easy. The mode button is harder.
I was thinking it would be good to be able to program one of the other pins as a secondary Mode button where either can work. The reason for this is that I am looking at a product that would be in an IP66 case, and this can be done if the unit is sealed. If it needs to be opened, such as to press a Mode button, there are other issues to be solved.