MCU: Freescale MKL26Z256VLH4

PTA01 connected to push button at lower right
PTA12 connected to push button at upper right ("play/pause")

PTE24 connected to push button at lower left
PTE25 connected to push button at upper left

PTE31 connected to push button at left middle ("brightness")

PTA0 ~= SWD_CLK
PTA3 ~= SWD_DIO