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Reading mouse over USB OTG port on Zedboard

average_mid

I am looking to develop my own custom IP in Vivado to read mouse input from the USB OTG port on a Zedboard (digilent.com/.../start).

I've scoured the internet for information but they almost all point to using PS/2 Pmods to achieve this. If I can read a flash drive using the OTG port, I should be able to read mouse signals provided I have the necessary USB A to microUSB adaptor. I'm not even sure where to start as computer mouse are HID devices and I don't quite know how a mouse's signal is presented over the OTG port.

Anyone with insight into this is greatly appreciated!

  • 0

    All the OTG signals on the Zedboard are wired to MIO pins on the Zynq.  That means you cannot access them from the PL programmable logic side.  They are configured to use the usb controller built into the PS processing system side.  If you want to write custom logic to implement OTG, you will need something like a PMOD board that is connected to the PL pins.

  • 0

    Even IF you could access the USB signals, USB HID is not a simple thing to process.  I've written HID gadget code before and there are a LOT of descriptors you'll have to anticipate and handle.  I suggest you go to https://www.beyondlogic.org/usbnutshell/usb1.shtml to get a basic tutorial.  From there, download the HID Class standard from the USB standards body.

    What is the real end goal of doing this?

  • 0

    I am not sure what is it you are trying to achieve. Here are few points:

    1- OTG is just USB Host or Device, depending on what you connect to the port. In your case it needs to be in Host mode for the mouse (device) to connect.

    2- As mentioned in a previews reply, the USB port on the board is part of the PS part, so no direct access to the PL.

    3- Before you you can even exchange HID or any other messages, you need to setup the USB host, which then enumerate the device (mouse) connected.

    4- Here is a link to mouse HID reference: https://www.usbmadesimple.co.uk/ums_5.htm I am not sure if it helps

    5- That is correct. Assuming you mean the software running on the PS 

    average_mid said:
    If I can read a flash drive using the OTG port, I should be able to read mouse signals provided I have the necessary USB A to microUSB adaptor