easiest way is to download the image that I used for this project: Turnkey PRU deskclock application for BBB
then, if I somehow modified the stock image and have forgotten about it, you will get that change as well… Is changing Uenv.txt disabling HDMI, etc what made it work for my system(s)… IDK b/c I dont remember.
the desk clock app does NOT use PWM in any way, but it is the image that I have on all my BBB…
let me know
gomer