Device Tree Overlay for BB

How to setup device tree overlay : If this works (as root), everything is great:

cd /lib/firmware
echo cape-universaln > /sys/devices/bone_capemgr.*/slots

However, an old version of universaln has a conflict with the HDMI/audio port P9.31 The updated version, should be included in this package as cape-universallc-00A0.dts can be used instead:

cp cape-universallc-00A0.dts /lib/firmware
cd /lib/firmware
dtc -O dtb -o cape-universallc-00A0.dtbo -b 0 -@ cape-universallc-00A0.dts 
echo cape-universallc > /sys/devices/bone_capemgr.*/slots

where cape-universallc has the lines corresponding to P9.31 commented out. To trace any erros, use dmesg | less.

To test if everything is expored coorectly, run (in julia, as root)

include("packages/LabConnections/test/BeagleBone/GPIO_test.jl")