I'm using the adapter that you see below to attach a VGA monitor to my smartphone and I see on the monitor what I see on my smartphone (samsung note 3) :

enter image description here

now,what I want to do is to find the working hub / adapter to attach also a keyboard and a mouse to use with the phone. I want to do these tasks simultaneously :

  1. using my old VGA monitor instead of watching on the phone screen
  2. using mouse and keyboard at the same time
  3. keep powered on 1 and 2 while I'm using them
  4. power on the hub adapter with an external power source

After some research I found this adapter and I bought it :


it works only if I attach the micro usb connector directly to the android phone. If I connect the micro usb connector to the vga adapter and the otg cable to the USB port of my pc and on the USB ports of the hub I attach a mouse and a keyboard,the VGA monitor works,but I can't use any USB devices because I see that they aren't reached by the power.

  • I'm lost at the last part.. could you elaborate more? Jan 7, 2021 at 14:52
  • check this picture to understand what I mean : ibb.co/7jgDL6r
    – Marietto
    Jan 8, 2021 at 12:10
  • add my answer for you to understand why Jan 8, 2021 at 13:35

1 Answer 1



The IC / microcontroller in your VGA adapter couldn't simultaneously convert the signal from USB to VGA (display) and providing a USB hub.

There is plenty of reason for that part :

  • The signal of USB data and VGA signal is different you can only choose either one of them.
  • The USB port only for the external device when the VGA is OFF, meaning the signal will switch back to USB data.

VGA signal:

VGA signal

USB signal:

USB signal

See the difference?


  • yes,thanks. what's the solution ? which adapter I need to achieve my goal ?
    – Marietto
    Jan 8, 2021 at 16:03
  • You gave some great information but I think you forgot to clearly answer the question that was asked. What adapter can OP buy to do USB + Video? You just explained why the adapter they have already won't work. Does your explanation also go as far as proving the phone itself can't output both signals? (I don't think it does because the video adapter might be using extra pins in a special microUSB port)
    – Romen
    Dec 1, 2021 at 21:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.