Enable UART1

Hello All,

I plan to use UART1 and UART2 of BBB for an application. I understand that only UART0 (which is any ways used for debug purpose) is enabled by default. As such, I see only ‘ttyO0’ in my ‘/dev/’ directory.

To enable UART1/2 , I added the following line in my uEnv.txt file :

#optargs=capemgr.enable_partno = BB-UART1,BBUART2

However, on reboot I don’t see ‘ttyO1’ and ‘ttyO2’ in my ‘/dev/’ directory.

What am I missing?


PS : I am using the BBB rev C with the stock Debian distribuition.

login as: debian
Debian GNU/Linux 7

BeagleBoard.org BeagleBone Debian Image 2014-04-23

Support/FAQ: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian
debian@’s password:
debian@beaglebone:~$ cd /lib/firmware
debian@beaglebone:/lib/firmware$ ls UART
ADAFRUIT-UART1-00A0.dtbo BB-UART1-00A0.dtbo BB-UART4-RTSCTS-00A0.dtbo
ADAFRUIT-UART2-00A0.dtbo BB-UART2-00A0.dtbo BB-UART5-00A0.dtbo
ADAFRUIT-UART5-00A0.dtbo BB-UART4-00A0.dtbo

In your uEnv.tx put
optargs=capemgr.enable_partno = BB-UART1,BB-UART2

you are missing one ‘-’, but have one too many ‘#’ - indicates comment

Hope this will help


Apologies for the delayed response. I work on this project mostly on weekends.
I had given up on editing uEnv.txt , but what worked for me was running the below command :

echo BB-UART1 > /sys/devices/bone_capemgr.*/slots

you didn't remove the "#" 'comment' character in front of the line in