Actually, I even tried to manually pass my P8_34 device tree overlay to the 
cape manager:
>
> /lib/firmware$ sudo sh -c "echo bone_pwm_P8_34 > $ SLOTS"


Then it looked good, like:

>  

root@beaglebone:~# cat $SLOTS

 0: 54:PF---

 1: 55:PF---

 2: 56:PF---

 3: 57:PF---

 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G

 5: ff:P-O-- Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI

 6: ff:P-O-- Bone-Black-HDMIN,00A0,Texas Instrument,BB-BONELT-HDMIN

 7: ff:P-O-L Override Board Name,00A0,Override Manuf,am33xx_pwm

 8: ff:P-O-L Override Board Name,00A0,Override Manuf,bspwm_P9_14_6

 9: ff:P-O-L Override Board Name,00A0,Override Manuf,bspwm_P9_22_13

10: ff:P-O-L Override Board Name,00A0,Override Manuf,bspwm_P8_19_4

11: ff:P-O-L Override Board Name,00A0,Override Manuf,bspwm_P8_46_b

12: ff:P-O-L Override Board Name,00A0,Override Manuf,bone_pwm_P8_34

But when I went to run the PWM channel, I got this error:

> error: Failed to find devicetree fragment: bspwm_P8_34_2
>
>
>
Please help! Thanks!!!
Donovan

On Sunday, February 8, 2015 at 6:33:59 PM UTC-8, [email protected] wrote:
>
> 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
>>>>
>>>

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