I have a 7 inch touchscreen from waveshare. The touchscreen works via HDMI to get the image and the power and touch function goes via usb to the pi. So the power comes from the pi...

The problem here is, I draw way too much amps from my pi when I turn the screen on... now what I want to acheve is that I can use the touchscreen as normal, but provide power to it via an extern power supply. So when I did this on the standard usb input, the touch stopped working. How can I fix this issue so I can have the touchscreen powered from an extern power supply but still have another usb cable that runs to the pi to get the touch to work?


To make it clear, some diagrams have been added.

This is how it is NOW: First

And this is how I want it, but I don't know if this is possible or not and how I should dot it:


  • Wait. In order to not power the LCD from the pi, you went from the pi's hdmi to the pi's USB?
    – mystery
    Apr 29, 2017 at 22:04
  • No, I always use the hdmi to get the image on the screen, but I used the usb ports on the pi to power it, however those can't deliver enough amps... so I used an external power supply. But then the touch doesn't work anymore... that's where I'm looking for to get a solution for it.
    – Robin
    Apr 29, 2017 at 22:07
  • Because you ran out of USB cables?. Also, what touchscreen is it? What LCD?, What power supply have you tried? There's a lot of information missing.
    – mystery
    Apr 29, 2017 at 22:10
  • Not because I ran out of cabels... I use the official 2.5 amps power supply of raspberry pi. And the lcd touchscreen is the 7inch touchscreen from waveshare, as said in the question...
    – Robin
    Apr 29, 2017 at 22:12
  • Maybe a diagram or picture of your setup would help with the confusion.
    – Jacobm001
    Apr 30, 2017 at 1:40

1 Answer 1


I've seen on another forum a tip, and I hope it helps: Use an externally powered USB Hub. It will supply power for both devices and the USB communication for your touchscreen.

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