Donovan: In your Molloy book, read about device trees, which set the default assignment of the I/O pins. Also read about the pin-mux. And related topics like pin-mux helper and device tree overlays. Then find the reference in the book to the BBBP8 and BBBP9 header file spread sheets on the web site for the book and down-load them.
There are up to eight different things that each pin can assigned to do. The ones that are giving you errors have been assigned to do things other than PWM. For instance, some are audio (mcasp0) pins, or some are LCD driver pins. There are multiple ways to reroute the functions, and change them from the default assignments, to the functions you want. But make sure that what they are doing is not important to the operation of the BBB. Enough of it is in the book, that you can figure it out. And the next time you ask for help, be sure to say what version of BBB you have, and what kind and version of OS you are running, because the answers/methods/rules are different on different versions of OS and hardware. --- Graham == On Sunday, February 8, 2015 at 7:28:16 PM UTC-6, donov...@gmail.com wrote: > > Also, I chose to explore these pins by doing: > > /lib/firmware$ *ls bone_pwm** > > as stated on p.231 of Derek Molloy's BBB book.. > > Thank you!!! > Donovan > > On Sunday, February 8, 2015 at 5:25:10 PM UTC-8, donov...@gmail.com wrote: >> >> Hello folks, >> >> I'm so frustrated. I can't find any pattern to why I can only get 3 PWM >> pins to work. Particularly, when I try to send a PWM command to some pins >> using "bb.analogWrite" it crashes my BBB. >> >> Error Details: >> "Failed to find device tree fragment." >> >> My Findings: >> Through some experimentation I've found this: >> 8_13 - Error >> 8_19 - WORKS >> 8_34 - Error >> 8_36 - Error >> 8_45 - Error >> 8_46 - Error >> 9_14 - WORKS >> 9_16 - Error >> 9_21 - Error >> 9_22 - WORKS >> 9_28 - Error >> 9_29 - Error >> 9_31 - Error >> 9_42 - Error >> >> Can someone tell me exactly WHY each of these pins works or doesn't work? >> I can't really find a pattern to this so I'm stumped. >> >> Thank you, >> Donovan >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
