Arduino Uno Button Box

Hey!

I have ordered 15 buttons for a sim racing button box and I am trying to use all 15 with my Arduino Uno R3.

I have tried UnoJoy but it doesn't support 15 buttons, only 13.

I know you can set the analog inputs for digital inputs, I have used it before.

Anybody have a library or know how to extend UnoJoy that will support 15 button?

Thanks in advance.

Edit:

Sorry found UnoDouble and flashed that on and it supports and works with 15 buttons