Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
Collapse
Brand Logo

ModalAI Forum

  1. ModalAI Support Forum
  2. Software Development
  3. VOXL SDK
  4. custom uart usage

custom uart usage

Scheduled Pinned Locked Moved VOXL SDK
5 Posts 2 Posters 778 Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • G Offline
    G Offline
    giladWDS
    Contributor
    wrote on last edited by
    #1

    Hi,
    I wanted to add a custom sensor to my voxel-2 through j19 UART.
    now I see that this UART is reserved to RC-inputs. but even when I disabled those in /etc/modalai/voxl-px4.conf, I still can't access the port.
    I looked a bit and found this:
    https://gitlab.com/voxl-public/voxl-sdk/core-libs/libqrb5165-io/-/tree/master/python?ref_type=heads
    and tried using it with port 7.
    when I tried to write it gave me the following:
    ERROR: voxl_uart_write: Bus '17' is not initialized
    and on init, it gave:
    Sending library name request: libslpi_qrb5165_io.so
    Sending initialization request
    Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
    Couldn't configure flight_controller sensor
    ERROR: fc_sensor_initialize failed
    ERROR: Failed to initialize slpi
    ERROR: Encountered error while initializing bus 17

    so it looks like it is still looking for some RC sensor.
    I guess my real question is how can I access SLPI UART as a user since I don't see them in /dev/tty*
    Thank you

    G 1 Reply Last reply
    0
    • G giladWDS

      Hi,
      I wanted to add a custom sensor to my voxel-2 through j19 UART.
      now I see that this UART is reserved to RC-inputs. but even when I disabled those in /etc/modalai/voxl-px4.conf, I still can't access the port.
      I looked a bit and found this:
      https://gitlab.com/voxl-public/voxl-sdk/core-libs/libqrb5165-io/-/tree/master/python?ref_type=heads
      and tried using it with port 7.
      when I tried to write it gave me the following:
      ERROR: voxl_uart_write: Bus '17' is not initialized
      and on init, it gave:
      Sending library name request: libslpi_qrb5165_io.so
      Sending initialization request
      Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
      Couldn't configure flight_controller sensor
      ERROR: fc_sensor_initialize failed
      ERROR: Failed to initialize slpi
      ERROR: Encountered error while initializing bus 17

      so it looks like it is still looking for some RC sensor.
      I guess my real question is how can I access SLPI UART as a user since I don't see them in /dev/tty*
      Thank you

      G Offline
      G Offline
      giladWDS
      Contributor
      wrote on last edited by
      #2

      @giladWDS To specify. my sensor is connected to a microcontroller. so also I prefer UART I can do i2c(I have tried and it didn't work as well) and I can do SPI if it works better.

      Eric KatzfeyE 1 Reply Last reply
      0
      • G giladWDS

        @giladWDS To specify. my sensor is connected to a microcontroller. so also I prefer UART I can do i2c(I have tried and it didn't work as well) and I can do SPI if it works better.

        Eric KatzfeyE Offline
        Eric KatzfeyE Offline
        Eric Katzfey
        ModalAI Team
        wrote on last edited by Eric Katzfey
        #3

        @giladWDS The I/O on J19 is only for use with the DSP, not the Linux processor. If you are running PX4 then you would need to write a custom PX4 driver for your sensor. The libqrb5165-io library would allow access to the UART but only if PX4 is not already running on the DSP. It's either PX4 or libqrb5165-io, you cannot use both at the same time. You can get an applications processor (Linux processor) UART via some of our add-on boards but there isn't one available directly from any of the I/O connectors on VOXL 2.

        G 1 Reply Last reply
        0
        • Eric KatzfeyE Eric Katzfey

          @giladWDS The I/O on J19 is only for use with the DSP, not the Linux processor. If you are running PX4 then you would need to write a custom PX4 driver for your sensor. The libqrb5165-io library would allow access to the UART but only if PX4 is not already running on the DSP. It's either PX4 or libqrb5165-io, you cannot use both at the same time. You can get an applications processor (Linux processor) UART via some of our add-on boards but there isn't one available directly from any of the I/O connectors on VOXL 2.

          G Offline
          G Offline
          giladWDS
          Contributor
          wrote on last edited by giladWDS
          #4

          @Eric-Katzfey
          Thank you for the reply
          The only board I have no for testing is:
          MCCA-M0151-1
          I use the USB portion for the wifi and see that it exposes a uart port- HS1 for the external USB board.
          I can't seem to communicate with this HS0 port as a standalone port.
          Is it only for external Flight controllers?

          I looked into this:
          https://docs.modalai.com/usb2-type-a-breakout-add-on/
          but it seems to expose the same uart I can not talk to.
          Can you please recommend me a board that won't affect the wifi capability but would add uart ports that I desperately need?

          • EDIT:
            also if push comes to shove I would appreciate sources on how to write and compile a px4 driver that reads from the uart on j19.

          Thank you and best regards,
          Gilad

          Eric KatzfeyE 1 Reply Last reply
          0
          • G giladWDS

            @Eric-Katzfey
            Thank you for the reply
            The only board I have no for testing is:
            MCCA-M0151-1
            I use the USB portion for the wifi and see that it exposes a uart port- HS1 for the external USB board.
            I can't seem to communicate with this HS0 port as a standalone port.
            Is it only for external Flight controllers?

            I looked into this:
            https://docs.modalai.com/usb2-type-a-breakout-add-on/
            but it seems to expose the same uart I can not talk to.
            Can you please recommend me a board that won't affect the wifi capability but would add uart ports that I desperately need?

            • EDIT:
              also if push comes to shove I would appreciate sources on how to write and compile a px4 driver that reads from the uart on j19.

            Thank you and best regards,
            Gilad

            Eric KatzfeyE Offline
            Eric KatzfeyE Offline
            Eric Katzfey
            ModalAI Team
            wrote on last edited by
            #5

            @giladWDS M0151 should expose /dev/ttyHS1 for use. It's just a UART so it isn't specific to external flight controllers.

            1 Reply Last reply
            0

            Hello! It looks like you're interested in this conversation, but you don't have an account yet.

            Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.

            With your input, this post could be even better 💗

            Register Login
            Reply
            • Reply as topic
            Log in to reply
            • Oldest to Newest
            • Newest to Oldest
            • Most Votes


            ModalAI
            Categories Recent Tags ModalAI.com Docs
            © 2026 ModalAI® · Accelerating autonomy for smaller, smarter, safer drones · Powered by NodeBB
            • Login

            • Don't have an account? Register

            • Login or register to search.
            • First post
              Last post
            0
            • Categories
            • Recent
            • Tags
            • Popular
            • Users
            • Groups