Fixing the screen flickering on a Dell Inspiron N5720 (and maybe many others)

I have a Dell Inspiron N5720 and was quite happy with it. After installing Windows 8 some mysterious screen flickering appeared. I ignored it for a while, but I noticed that it only happens when not plugged in. So only a few possibilities are left:

  • The graphics card/display/something in between is broken
  • The battery is defect
  • Something is wrong with the drivers

Checking the first two possibilities would’ve been too time consuming without a real result. And it’s kind of unlikely that the battery and/or graphics card broke just as I installed Windows 8. And the fact that it only happens when on battery is also a good hint, as this indicated that it could be something with the power saving settings (spoiler: it was).

A Dell Inspiron N5720 has a nVidia GT 630M and an Intel HD Graphics 4000. Let’s see what the Intel Graphics Control panel looks like. To open it, follow these instructions.

Select Advanced mode.

Go to the Power menu and change the power source to “On battery”. Now uncheck the little check box that says “Display Refresh Rate Switch”. Apply. OK. And you’re done.
And that’s it. Never had another screen flicker after that. I assume that this could solve the screen flickering on most, if not all laptops with an Intel HD Graphics 4000. Hope it helps!
EDIT:
It seems like Windows 8.1 isn’t kind to us. Among other problems, the flickering, even if fixed before the update, returns once the update is complete. The option that prevents flickering still exists, it’s just kind of hidden now. I fixed it this way:
  • Right click on desktop.Go to “Graphics settings” or however they call it now (they forcefully localize this stuff now..) This should appear:

Power Settings

  • Click on Power, then on “On Battery”.

New Intel HD panel

  • Switch it to maximum performance, and turn off the “Display power saving technology”.

I hope this helps. I haven’t had flickers since the update after changing this.

Setting everything up for OpenCV

Hello!

I’ve always be fascinated with Computer Vision. I made a few prototypes, tested a few things and it was fun. It weren’t the most optimal solutions, but they worked. I always knew that OpenCV exists, but never really bothered to try it out. Well, until now.

It turns out setting this beast up isn’t really as easy as I thought. So I decided to write a few guides how to do it. I will use it primary on the Raspberry Pi, and programming will most likely take place on my Windows machine in Python.

  1.  Setting everything up for OpenCV РRaspberry Pi on Raspbian
  2.  Setting everything up for OpenCV РWindows 7

Feel free to leave a comment!