Macro-pad using Arduino mini 32u4. Full project details on Thingiverse.
Pin mappings are as follows:
BUTTON INPUTS
9 - Left button section 1st from left edge
8 - Left button section 2nd from left edge
7 - Left button section 3rd from left edge
4 - Left button section 4th from left edge
16 - Top middle white button
14 - Bottom middle white button
15 - Right button section 4th from right edge
A0 - Right button section rd from right edge
A1 - Right button section 2nd from right edge
A2 - Right button section 1st from right edge
LED OUTPUTS
3 - Left button section
5 - Top middle white button
6 - Bottom middle white button
10 - right button section