kedei 3.5 inch 480x320 tft lcd made in china

While googling for any info about lcd controller I came across this page: http://heikki.virekunnas.fi/2015/raspberry-pi-tft/, author managed to get from manufacturer patch file for kernel sources and tested it with 4.1.y - on which lcd worked. But still LCD replace HDMI, but I want to use this screen as additional for user interaction, while the bigger on HDMI as presentation monitor.

Since, fbtft has been merged with rpi kernel, so the fb drivers (including ili9341.c) was moved to fbtft_device driver (so the author of page can"t compile latest kernel with driver+patch).

So something about hardware, which I reverse engineered by the "hard way" - "grab multimeter and run through all LCD FPC pins and shift register pins"

Now I noticed there is "9486L" which can suggest that LCD screen is controlled by ILI9486L, I found this LCD on taobao too but I can"t contact seller.

I"m pretty sure about D/C (Pin 37 on LCD) and Reset (Pin 19 on LCD) pins by looking into driver code, but I can"t identify other signals (WR/RD/CS/etc...)

- Controller is not ILI9341/ILI9325 - those are for smaller displays (320x240, etc...), I guess this might be ILI9486/9488 because they are for 480x320 displays. But when I compared init with DS it does not fit right so LCD can have a clone of ILI9486/9488 ...

- Module use only SPI interface and two CE signals (CE0 for touch controller, CE1 for LCD shift registers - compared to others lcd modules, in KeDei module this is swapped),

I finally received my 3.5" KeDei 480x320 16bit/18bit version 3.0 TFT LCD touchscreen from Hong Kong. It only connects through the GPIO pins. I plugged it into my Raspberry Pi 2 and I was met with a white screen when I tried both the Ubuntu and Raspbian images.

The RPi LCD can be driven in two ways: Method 1. install driver to your Raspbian OS. Method 2. use the Ready-to-use image file of which LCD driver was pre-installed.

3) Connect the TF card to the Raspberry Pi, start the Raspberry Pi. The LCD will display after booting up, and then log in to the Raspberry Pi terminal,(You may need to connect a keyboard and HDMI LCD to Pi for driver installing, or log in remotely with SSH)

1. Executing apt-get upgrade will cause the LCD to fail to work properly. In this case, you need to edit the config.txt file in the SD card and delete this sentence: dtoverlay=ads7846.

This LCD can be calibrated through the xinput-calibrator program. Note: The Raspberry Pi must be connected to the network, or else the program won"t be successfully installed.

I orderer a 3.5″ SPI touchscreen with a Raspberry Pi 2 and a case, thinking it would be easy to set up, as it seemed to be like the one here. Unfortunately that was not the case.

With some googling I found out it was made by KeDei LCD and exactly this screen. Identifying strings on the screens were “Madei in KeDei of china”, “3.5 linch SPI TFTLCD”, “480*320 16bit/18bit” and “vision 1.0 2015/6/11”. I hope the guys who made this screen can write code better than english… Seems like it requires custom drivers by KeDei. Drivers could be downloaded from Baidu and they include the diff to compile your custom kernel. I haven’t compiled kernels before, so lets see if I could manage without doing that.

I installed Ubuntu on my Macbook Pro on an external hard drive (which is a whole another story, thanks to EFI), so I could follow instructions on Raspberry Pi pages. Compiling on RPi is quite slow (tried that overnight), so cross compiling is the way to go. Following the instructions worked pretty well, however I cloned tools to my home directory and added /home/heikki/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin to my path. After that everything worked as expected. After cloning and changing branch to rpi-4.1.y I patched semi-manually from the supplied diff from KeDei, however I have uploaded my updated diff to make it easier for you. There’s instructions on patching too, but long story short it’s “cat | patch -p1” in the base directory of the clone. The version I used was branch rpi-4.1.y, commit 785cea66a709eddb9858799192a7b7da566b44b0.

You should now have two framebuffer devices, /dev/fb0 and /dev/fb1. I’m not quite sure how the fbtft library interferes with the patch, as it seems to be activated too, but it works so no problem. (Actually I first activated module fb_ili9341, so you can try that too, if it contributed to my success). You can change to console to fb1 by command “con2fbmap 1 1” and back with “con2fbmap 1 0“, or on boot by editing /boot/cmdline.txt: add “fbcon=map:1” to the line somewhere. You can also change the font with “fbcon=font:ProFont6x11“. More things like this here.

I haven"t had the opportunity to try it on a Raspberry Pi yet. From pinouts of raspi (googled images) they only have one long strip of GPIO/etc connectors, do they not? Even if plugging this board onto the 40-pin connector, where the two 5V pins match up, on the raspi the opposing two aren"t GND, they"re listed as "+3,3V" and "SDA". Something tells me that.. well, either I"m missing something, or this display needs some form of connector between itself and the raspi it"s meant to run off originally. (Oddly enough, they came with raspi-with-TFT-on-top plastic enclosures, which wouldn"t leave any space for rewiring pins.)

I doubt it. It would be a lot cleaner with regular SPI for both. You just change mode each time. e.g. 9-bit mode #3 for TFT. 8-bit mode #0 for the XPT.

Ah-ha. The HC595 is a shift register. They might use them to produce 16-bit parallel to drive the TFT. If they do, it will be a nightmare. Even worse than 9-bit SPI.

Well, it"ll be interesting to see if I get this to work eventually. A quick guess would be that with L_CS pulled low, the LCD chip gets to talk with the MISO/MOSI lines. After initializing it, I suppose the next step will be to (read datasheet..) and see if the MISO/MOSI-lines are used to clock out display data with L_CS high so the LCD chip doesn"t listen to that garbage, or if it is meant to be fed through the LCD chip aswell.

Oh, this makes it easier - googling for the tarball I needed (lcd_show_v6 for my board since it"s got "v6.1" printed on it) got me to OsoYooTFT/README.md at master · jgamblin/OsoYooTFT · GitHub and http://en.kedei.net/raspberry/raspberry.html

Hrmm.. I don"t think source is included. In the lcd_show_xx blobs are just kernels and modules, with a couple of very small scripts to copy the LED or HDMI kernel to the /boot place of the filesystem. (And no error checking, if you try copying the LED kernel, it backups the original kernel, but if you then run the copy-LED-kernel command again, it happily overwrites your original kernel, leaving you with two LED-enabled kernels and no original. hrrf..)

Well, I downloaded the whole 35MB .GZ file. Unpacked it and found 3402 .ko files. I presume that these are kernel object files. Nothing that looked remotely like source files for your TFT display.

This suggests more control bit are shifted in than is actually needed, but my hunch of an 18 bit + control parallel interface to the TFT seems to be correct.

Yes, I expect that bodmer or myself could probably get you working if we made some inspired guessing with the schematic. You could always email Kedei and ask him for the genuine schematic. Make sure that you tell him the Revision number(s) on the pcb.

I had success with downloading Kedei"s 4GB images specific for the 6.1 board and putting on an SD card. Now the raspi boots up, and I see the boot messages scroll by. The original article said "expect about 6fps from the display" and that seems right - it"s jerky, but works.

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.

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 ishttp://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.

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.

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!

While googling for any info about lcd controller I came across this page: http://heikki.virekunnas.fi/2015/raspberry-pi-tft/, author managed to get from manufacturer patch file for kernel sources and tested it with 4.1.y - on which lcd worked. But still LCD replace HDMI, but I want to use this screen as additional for user interaction, while the bigger on HDMI as presentation monitor.

Since, fbtft has been merged with rpi kernel, so the fb drivers (including ili9341.c) was moved to fbtft_device driver (so the author of page can"t compile latest kernel with driver+patch).

So something about hardware, which I reverse engineered by the "hard way" - "grab multimeter and run through all LCD FPC pins and shift register pins"

Now I noticed there is "9486L" which can suggest that LCD screen is controlled by ILI9486L, I found this LCD on taobao too but I can"t contact seller.

I"m pretty sure about D/C (Pin 37 on LCD) and Reset (Pin 19 on LCD) pins by looking into driver code, but I can"t identify other signals (WR/RD/CS/etc...)

- Controller is not ILI9341/ILI9325 - those are for smaller displays (320x240, etc...), I guess this might be ILI9486/9488 because they are for 480x320 displays. But when I compared init with DS it does not fit right so LCD can have a clone of ILI9486/9488 ...

- Module use only SPI interface and two CE signals (CE0 for touch controller, CE1 for LCD shift registers - compared to others lcd modules, in KeDei module this is swapped),

I can confirm that the 3.5 inch LCD touch screen from kedei works with raspbian stretch. I have to use the latest driver at http://en.kedei.net/raspberry/v6_1/LCD_show_v6_1_3.tar.gz

I had in plans to create a custom driver but I decided this is not worth my time. I"m going to "re-interface" this lcd to be supported by fbtft. I have a prototype pcb with fbtft-spi interface ready (I have to send this project to pcb prototype service).

... height with supports. ...This bracket will accommodate the Kedei 3.5" HDMI LCD screen, using kapakahi"s screw posts. The button wells from kapakahi"s original Thing will also fit. ...

Remix Raspberry Pi Display Case http://www.thingiverse.com/thing:1229473 For the KeDei 3.5" SPI TFTLCD 480x320 version 1.1 2015/8/11 Print Settings Printer Brand: RepRap Printer: reprap prusa i3 marlin Rafts: Doesn"t Matter Supports: No Resolution:...

So I ordered the OSOYOO 3.5" TFT display from Amazon (also seen it for sale as a KeDei display which is what is actually printed on the OSOYOO I received from Amazon), and I wanted a simple case for it that would hold & display it nicely with all...

... stl orientation- screen.stl should be printed downwards. -So the supports go on top of the mounting screws. Screen has some freedom of movement on the back of the pi, just dab som hotglue to the edge of the kedei-pcb and have a good time! ...

I love the case made by 0110-M-P and I couldn"t find a good case for cheap 3.5 kedei LCD so I made a top for 0110-M-P base. I"m using this with my octoprint and touch UI.

My touchscreen (KeDei (ebay)) was a bit higher to fit the original case so I made the display-slot slightly taller for the case and cap. ...Works with the following Raspberry Pi Models:

A Gameboy Zero Helper for the Kedei 3,5 " Display Space for micro usb break out, usb and volume wheel the top adds more useable space into your build print solid and drill the holes by your self

Screen used is KeDei 3.5 inch LCD TFT 320x480 touch screen (sample link https://www.aliexpress.com/item/New-Original-3-5-Inch-LCD-TFT-Touch-Screen-Display-for-Raspberry-Pi-2-Raspberry-Pi/32851565266.html). ... You will need: - The screen (KeDei 3.5 inch...

I have the KEDEI 3.5" 128M SPI TFT screen, and had to modify it slightly: "extending the connector with wires", which gives the opportunity to add some more things like better power connection or i2c RTC. I made the case for the screen to cover the...

... On an ugly reprap display I also deliberately omitted, since I use octoprint touch (with a osoyoo / kedei 3.5 "HDMI touch TFT https://amzn.to/2IivrUA). ...