Using UE4Duino to read a button and change a color of a particle

Hello peeps,

The thing I want to create:
I want a button on my arduino to change the color of a particle system.

Currently I have the K and L button to change the color of the particle so that is working. But now comes the part of using UE4Duino. I want the button on my arduino to replace the K and L button (or to fuction as the K and L button if possible).

I am really new to UE4 and Arduino. I think what I want should not be to hard but I don’t really know how to read the UE4Duino-plugin and have little time to get really in-depth as this is a school project.

My current key pressed event looks like this:

I hope anyone could help me with this, or link to a similar situation.