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3.5″ LCD TFT Touch Screen Display Kedei on AliExpress

When surfing for information on 3.5 ” TFT touchscreens for the Raspberry Pi, to improve the TinyLCD experience, I stumbled upon AliExpress where several shops offer a 3.5″ LCD TFT Touch Screen Display for incredible low prices.


So I ordered two for the price of $14,85, postage included. A acrylic case and stylus is also included in that price! The shop Soonics has good reviews, but you  never know if one can trust that.

Here my experiences with the screen: quite slow refresh, not too high contrast, crisp screen, touch works, software works but is already outdated, but considering the price this screen is well worth the money! If I compare it to the NeoSec screen it is a better deal for applications with a high contrast theme and no demand on smooth video.

IMG_4525a IMG_4525The specifications are:

  • LCD Interface: SPI
  • Touch Screen Controller: XPT2046
  • Backlight: LED
  • LCD Type: TFT
  • Resolution: 320*480 DOTS
  • Core System: vision 3.18.9
  • SPI Speed: 32MHz
  • Color Levels Index: 65536

Sounds too good to be true? Ordered October 18, received 29 oktober, not bad for standard shipping from China!

Well packaged in a box, the displays wrapped in bubble packaging.

So now for the test. On the sellers page an URL is placed to get the software, on a Google drive. Not a clickable url, but an image with a long filename to type over …. Oh well, I got the archive.

Update June 2016: There is now a download/information page at http://osoyoo.com/driver/rpiscreen.php. Images for more versions (mine i 2.0, latest is 6.2)  are available there. Alternative is http://kedei.net/raspberry/raspberry.html with Kali Ubuntu drivers too for version 3.0 and up.

The archive contains an image of Raspbian with the LCD driver installed. The image is quite current, and fit for B, B+ or 2 B. When I bought the screen an older image, build in augustus 2015,  was downloadable, the kernel is quite fresh built, early October 2015.

IMG_4533 IMG_4532 IMG_4531After imaging and booting on a RPi 2 B I saw the normal startup messages flying (eh, crawling ..) over the touchscreen and the desktop appeared in the normal way.

The image supplied is wheezy,  3.18.9-v7 #27 SMP PREEMPT Sun Oct 4 23:57:41 CST 2015 armv7l. So quite a recent system! Also the Model 1 B and B+ kernel is present, also just current wheezy.

In a separate image I found two shell scripts to replace the kernel with either a HDMI or a LCD patched one. Handy!

Now the bad news: no word how these kernels were build. So we are stuck with wheezy for now until the Chinese supply a more current build, hopefully based upon jessie. Until then: be careful updating the system by holding back on kernel updates.

 
sudo apt-mark hold raspberrypi-bootloader
sudo apt-get update 
sudo apt-get upgrade

The system uses SPI to copy the screen contents to the LCD screen, and some GPIO’s for the touchscreen. Other GPIOs are free, and the connector construction  leaves these pins indeed accessible!

UT8lie.XuxaXXagOFbXo

The acrylic case is not something special, it looks like the usual cheap thing without the top plate. The screen fits in the hole, but is not supported by it, instead it rests on the USB connectors. IMG_4528

Build your own kernel:

See these posts:

http://heikki.virekunnas.fi/2015/raspberry-pi-tft/

http://frec.pl/blog/compiling-custom-raspberry-pi-kernel-with-kedei-35/

13 thoughts on “3.5″ LCD TFT Touch Screen Display Kedei on AliExpress

  1. Hi, thanks for this post 🙂
    Yesterday I arrived the same 3.5″ display from AliExpress (-;
    Is possible to use both displays – this 3.5″ LCD and fullHD via HDMI in the same time?
    The drivers for this 3.5″ LCD are included in kernel? So is there no way to upgrade kernel?
    Is possible to change the backlight intensity?

    Thanks for your response.
    Regards
    Bagican

  2. Thank you for this post, very useful. I have bought the exact same touch screen display, and could not understant how to update the system without loosing the display. You post helped me fix this.

    Do you know how that would be possible to find a specific driver for this display? That would allow to get rid of the dependency to this third party image. I have tried the Adafruit touch screen driver, without success.

  3. What software needs to be on the sd card in order for this sucker to work? iv tried almost every site i could find and it still isn’t working. where can i download this software and what software do i need on my windows 8.1 laptop?

  4. Really! This is it?! from what I heard from others is that you needed to install their driver. Also, is this going to be able to run python idle or will I have to install that on the sd card too? Thanks a lot for your help so far, I really appreciate it.

    • Worked for me out of the box. Limited to older wheezy, so make sure the kernel is protected for apt-get upgrade etc. See my blog on that.
      $ sudo apt-mark hold raspberrypi-bootloader
      raspberrypi-bootloader set on hold.

      There are files and instructions how to add the adapted kernels etc in the archive. Still limited to older wheezy. But it works for me with what I do with it.

      Python idle needs an install. BUt it will be of limited use on this tiny screen, much of the interface will be offscreen and it so slow in screen updates. This is not an alternative for a real monitor, 800×600 is a minimal size, 1024×768 is even better. An older cheap DVI lcd screen with a HDMI to DVI adpater (passive, $2 on ebay) is for development usefull.

      • Ok this still doesn’t make sense to me, I tried exactly what you said and it doesn’t work. Can you or somebody else please post a video of the whole process on how to get this thing working from a totally blank sd card? This would help so much. Please.

  5. ok I got it to work but can somebody tell me how to permanently change the size of the windows because they are way out of scale.

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