ModalAI Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Register
    • Login

    VOXL as usb2 host not working via j8

    VOXL
    2
    3
    242
    Loading More Posts
    • 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.
    • NirgeN
      Nirge
      last edited by

      Hi,
      Connecting my laptop to voxl via adb works on j8 connecter.
      However, an STM based device is not recognized when connecting a client device to voxl using micro-usb to micro-usb cable.
      The same device is recognized when connecting via the usb expander (https://docs.modalai.com/usb-expander-and-debug-datasheet/)

      Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
      Bus 001 Device 002: ID 0483:5740 STMicroelectronics STM32F407
      Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
      

      https://docs.modalai.com/voxl-as-usb-host/ does not specify any special requirements.
      Am I missing something? is the micro-usb cable needs to be an OTG cable with ID pin?
      Best regards,
      Nir

      1 Reply Last reply Reply Quote 0
      • modaltbM
        modaltb ModalAI Team
        last edited by

        Hi @Nirge ,

        A standard cable won't work.

        Some info here:
        https://docs.modalai.com/voxl-datasheets-connectors/#notes-3

        From here: https://docs.modalai.com/voxl-as-usb-host/#background

        Because the USB3.0 SS pins on the VOXL (Snapdragon 821) cannot support TX/RX swapping, they were set to peripheral mode since the 821 is used mainly in phones and peripheral mode is way more commonly used in a phone configuration.
        
        In order for systems to use the standard micro-b to type A female OTG cables, they need to do TX/RX swapping.
        
        Since VOXL can't do this, it needs to use a non-standard pinout as its default configuration is peripheral mode in order to get the SS.
        
        NirgeN 1 Reply Last reply Reply Quote 0
        • NirgeN
          Nirge @modaltb
          last edited by

          @modaltb Using USB 2.
          Got my hands on an OTG adapter, seems to be doing the trick.

          1 Reply Last reply Reply Quote 1
          • First post
            Last post
          Powered by NodeBB | Contributors