• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 98 subscribers
  • Views 700 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM3358: UART configuration problem

Jack Knight
Prodigy 105 points
Part Number: AM3358
Other Parts Discussed in Thread: MAX232

  • TI Processor SDK 06_00_00_07
  • Host computer: Ubuntu 18.04
  • Development board: Beaglebone Black rev-C (BBB)
  • (1) 16GB micro SD card with Debian BeagleBoard image. I used dd command with beagle board image to create this card.
  • (1) 16GB micro SD card with TI default tisdk-rootfs-image-am335x-evm.tar.gz image from SDK. I run /bin/create-sdcard.sh to create this SDcard.

I have a (2) MAX232 RS-232 chip connected to UART1,2,4 proven to work. My host: ttyS0 (physical RS-232 port) is connected to BBB: UART-4 via 9-pin RS-232 cable. My host: ttyUSB0 is connected to BBB: UART-0 (6-pin header) via FTDI cable.

  1. On my host, start putty session connect to host: ttyS0
  2. On my host, start minicom session connected to host: ttyUSB0.
  3. Boot Debian BeagleBoard image from SDcard, watch host: minicom session and wait for boot to complete
  4. Login as debian
  5. Type 'sudo echo "12345 From UART-4" > /dev/ttyS4'

Checking putty will show "12345 From UART-4" which proves BBB: ttyS4 (UART-4) can open and send text.

  1. On my host, start putty session connect to host: ttyS0
  2. On my host, start minicom session connected to host: ttyUSB0
  3. Boot TI default image from SDcard, watch host: minicom session and wait for boot to complete
  4. Login as root
  5. Type 'sudo echo "12345 From UART-4" > /dev/ttyS4'

Checking putty shows no message. Checking minicom shows BBB error '-sh: echo: write error: Input/output error'.

How do I enable UART1,2,4 (ttyS1,ttyS2,ttyS4) in the TI default image?

Thank you,

  • 0
    TI__Guru**** 172861 points

    Hi Jack,

    The TI default image only has UART0 enabled for AM335x, the rest of the UARTs are disabled in the device tree. You can modify the device tree file to enable UART1,2,4, the pinmux has to be set properly for UART mode and the UART dt node has to be set to enabled.

    If you are not sure how to implement it, you can either compare the device tree files in kernel source code between the TI Processor SDK kernel and the Debian kernel you tested; or search on this forum - this question has been asked and answered many times.

  • 0 in reply to Bin Liu
    Prodigy 105 points

    Bin Liu,

    Your answer helped by telling me that I need to modify the device tree. Based upon this post. e2e.ti.com/support/interface/f/138/t/749341, I was able to add uart1,2,4,5 support.

    Thank you,

  • 0 in reply to Jack Knight
    TI__Guru**** 172861 points

    Hi Jack,

    I am glad the issue is solved. Thanks for the update.