Using UART3

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Michael Williams

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May 11, 2016, 1:41:41 PM5/11/16
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Has anyone been able to enable and use UART3 (ttyO3) on the Beaglebone Black?  Any tips or tricks to share?

Robert Nelson

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May 11, 2016, 1:45:06 PM5/11/16
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On Wed, May 11, 2016 at 12:41 PM, Michael Williams <mikey...@gmail.com> wrote:
Has anyone been able to enable and use UART3 (ttyO3) on the Beaglebone Black?  Any tips or tricks to share?

Access to uart3_rxd is not available on the headers...

Regards,

--
Robert Nelson
https://rcn-ee.com/

Michael Williams

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May 11, 2016, 1:50:05 PM5/11/16
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Thank you for your input.  You cannot enable uart3_txd?

Robert Nelson

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May 11, 2016, 1:53:09 PM5/11/16
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On Wed, May 11, 2016 at 12:50 PM, Michael Williams <mikey...@gmail.com> wrote:
Thank you for your input.  You cannot enable uart3_txd?

Sure you can enable that one:


Just add:

cape_enable=bone_capemgr.enable_partno=BB-UART3

to /boot/uEnv.txt

Regards,

Michael Williams

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May 11, 2016, 2:48:05 PM5/11/16
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Thank you, Robert, for the tips and files.  Still not having luck with enabling the uart3_txd.  With the github file, linked above, does that have to be put in a special place and does it need compiled?  Also, can the other uarts be enabled along with the uart3_txd?  Normally, I include this "cape_enable=capemgr.enable_partno=BB-UART1,BB-UART2,BB-UART4,BB-UART5" in my uEnv.txt file so I can enable those uarts.  I have tried issuing adding the line you sent me, "cape_enable=bone_capemgr.enable_partno=BB-UART3", both with and without my normal line and still not seeing the uart3_txd(ttyO3) listed in device list.

I appreciate your help with this matter.

Regards,

Mike

Robert Nelson

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May 11, 2016, 2:55:08 PM5/11/16
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On Wed, May 11, 2016 at 1:48 PM, Michael Williams <mikey...@gmail.com> wrote:
Thank you, Robert, for the tips and files.  Still not having luck with enabling the uart3_txd.  With the github file, linked above, does that have to be put in a special place and does it need compiled?  Also, can the other uarts be enabled along with the uart3_txd?  Normally, I include this "cape_enable=capemgr.enable_partno=BB-UART1,BB-UART2,BB-UART4,BB-UART5" in my uEnv.txt file so I can enable those uarts.  I have tried issuing adding the line you sent me, "cape_enable=bone_capemgr.enable_partno=BB-UART3", both with and without my normal line and still not seeing the uart3_txd(ttyO3) listed in device list.


cape_enable=capemgr.enable_partno=BB-UART1,BB-UART2,BB-UART3,BB-UART4,BB-UART5 

Regards,

Wally Bkg

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May 12, 2016, 8:26:59 AM5/12/16
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Assuming he's using one of the newer images,
Any reason it can't be done with config-pin instead of an overlay?

Michael Williams

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May 12, 2016, 9:10:45 AM5/12/16
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What image do I need to be using, in order to use the uart3_txd?  I am currently using Debian, version 3.8.13-bone79.

Michael Williams

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May 12, 2016, 9:59:52 AM5/12/16
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I apologize for bothering you again.  I seem to be having a problem compiling the BB-UART3-00A0.dts file that you sent me a link to.  Here is the command I issue to compile it.  "dtc -O dtb -o BB-UART3-00A0.dtbo -b 0 -@ BB-UART3-00A0.dts"  I have tried several times and have received the following error  

"Error: BB-UART3-00A0.dts:11.1-9 syntax error
  FATAL ERROR: Unable to parse input tree"

is there a trick or something special I need to do to compile it to get it to compile correctly?

Thanks again,

Mike

Robert Nelson

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May 12, 2016, 10:04:54 AM5/12/16
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On Thu, May 12, 2016 at 8:59 AM, Michael Williams <mikey...@gmail.com> wrote:
I apologize for bothering you again.  I seem to be having a problem compiling the BB-UART3-00A0.dts file that you sent me a link to.  Here is the command I issue to compile it.  "dtc -O dtb -o BB-UART3-00A0.dtbo -b 0 -@ BB-UART3-00A0.dts"  I have tried several times and have received the following error  

"Error: BB-UART3-00A0.dts:11.1-9 syntax error
  FATAL ERROR: Unable to parse input tree"

is there a trick or something special I need to do to compile it to get it to compile correctly?

Well it doesn't matter as you are using 3.8.13-bone79


is 4.1.x+ only..

Regards,

evilwulfie

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May 12, 2016, 10:09:49 AM5/12/16
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dont you love the error when compiling ?
no line number or more infos to help you troubleshoot.

have you modified it in any way ?


i had issues manually compiling so i just used the makefile

make clean then make and if all went well a sudo make install
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Robert Nelson

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May 12, 2016, 10:12:47 AM5/12/16
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On Thu, May 12, 2016 at 9:09 AM, evilwulfie <evilw...@gmail.com> wrote:
dont you love the error when compiling ?
no line number or more infos to help you troubleshoot.

The issue, he didn't run gcc pre-proccessor on it. ;)

Easier to just run make in the included makefiel..
 

have you modified it in any way ?


i had issues manually compiling so i just used the makefile

make clean then make and if all went well a sudo make install

Regards,

Michael Williams

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May 12, 2016, 3:10:51 PM5/12/16
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Ok. I have made a bit of progress, this afternoon.  

I finally was able to get the file you sent me to compile with the dtc version that I have.  The only problem, is it is not assigning BB-UART3 to /dev/ttyO3 for use.   Attached is my updated ".dts" file.  

Thanks again for your help.

Regards,

Mike
BB-UART3-00A0.dts

Robert Nelson

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May 12, 2016, 3:21:09 PM5/12/16
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On Thu, May 12, 2016 at 2:10 PM, Michael Williams <mikey...@gmail.com> wrote:
Ok. I have made a bit of progress, this afternoon.  

I finally was able to get the file you sent me to compile with the dtc version that I have.  The only problem, is it is not assigning BB-UART3 to /dev/ttyO3 for use.   Attached is my updated ".dts" file.  

if you are still using 3.8.13, see this:


Notice:

target = <&uart5>; /* really uart4 */

Change your &uart3 to &uart4...

Regards,
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