Thanks for the advice, Graham. After disabling HDMI by editing uEnv.txt, I was able to gain functionality of these pins:
8_36 (works but requires EHRPWM1A but that is already in use by 9_14) 8_45 (works but requires EHRPWM2A but that is already in use by 8_19) 8_46 (this one seems to work well) *Can you please explain to me why disabling HDMI didn't help 8_34 work?* By the way, I'm on Debian GNU/Linux 7 and my BBB was Rev. C. Thanks!!! On Sunday, February 8, 2015 at 6:04:50 PM UTC-8, Graham wrote: > > 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, [email protected] 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, [email protected] >> 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
