Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Wed Oct 11, 2017 2:54 am

I do not understand how to enter these teams in Raspberrypi(

Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Thu Oct 12, 2017 3:14 pm

I added text to the Config file.
I put the screen on top and he still does not work (

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saper_2
Posts: 232
Joined: Sun Aug 03, 2014 10:08 am
Location: PL

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Thu Oct 12, 2017 6:08 pm

Hi,

Check if your display works at all: take the display (if u have it connected to RPi then disconnect from Pi), connect to display only power via microusb , toggle switch to see if it will lit up at all - Working display without RRi (nor connected signal to HDMI) should be blue (it might show up "no signal" and/or KeDei logo - see photos (and my movie - I don't remember if I have one :) )).

When U confirm it power up ok, then connect signal via HDMI to it, e.g. from computer (and don't forget to enable external(2nd) display in your computer.. :shock: ) - just to test it if the display work ok.

Now, connect it to RPi and don;t forget about the hdmi connector board 8-) , connect to RPi LAN (,usb mouse, keyboard if u need), and connect the microusb power not to the Pi but to the display. Pi should bootup - if u have already enabled (added if not exists) and set config values in config.txt then u should see picture - notice: don't config touch for now, just setup only display to see if it works. If u have working display then start playing with touch... and there is end of my help - I don't have touch in my display :lol:

Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Fri Oct 13, 2017 6:00 am

The display is working.
The lights are blue and the inscription Kedey.
I put it on Malinka, connected it to an HDMI bridge.
In the config file, the text inserted above.
Through remote access the system works, but the screen does not (

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saper_2
Posts: 232
Joined: Sun Aug 03, 2014 10:08 am
Location: PL

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sat Oct 14, 2017 1:03 pm

I don't know what u're doing wrong....

The display (my at least) work out of box (well it's not very readable) but at least I can see if it works:
disp-working-after-first-boot.jpg
disp-working-after-first-boot.jpg (31.59 KiB) Viewed 4049 times
Here is a full my config file, I tested it on latest rapsbian 2017-09-07-raspbian-stretch.img :

Code: Select all

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# Force use HDMI
hdmi_force_hotplug=1
# force a specific HDMI mode
hdmi_group=2
hdmi_mode=87

# custom display resolution (480x320 looks good , and 720x480 is not too bad too,3rd res is: 810x540 )
#         /----------------- Width: 480px ( or 720px /or 810px)
#         |   /------------- Height: 320px ( or 480px /or 540px)
#         |   |   /--------- Refresh: 60Hz
#         |   |   | /------- Aspect ratio: 6=15:9 (1=4:3, 2=14:9, 3=16:9, 4=5:4, 5=16:10)
#         |   |   | | /----- Margins: 0=disabled (1=enabled)
#         |   |   | | | /--- Interlace: 0=progressive (1=interlaced)
#         |   |   | | | | /- Reduced blanking: 0=normal (1=reduced)
#         |   |   | | | | |
hdmi_cvt 480 320 60 6 0 0 0

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable the lirc-rpi module
#dtoverlay=lirc-rpi

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on
Also here is 2 photos how deep the hdmi bridge should go into hdmi connectors (I marked a black line on the plugs how deep it must go):
disp-plug2.jpg
disp-plug2.jpg (25.33 KiB) Viewed 4049 times
disp-plug1.jpg
disp-plug1.jpg (16.76 KiB) Viewed 4049 times

Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sun Oct 15, 2017 10:10 am

Do I need to replace the entire configuration file?
Or below to add your code?

Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sun Oct 15, 2017 10:26 am

Friend, here's the video: https://www.youtube.com/watch?v=yVk9u0f31I4
The screen shows, but very badly.
Then goes out and all.

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saper_2
Posts: 232
Joined: Sun Aug 03, 2014 10:08 am
Location: PL

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sun Oct 15, 2017 10:39 am

Hi,

Krot wrote:
Sun Oct 15, 2017 10:26 am
Friend, here's the video: https://www.youtube.com/watch?v=yVk9u0f31I4
The screen shows, but very badly.
Then goes out and all.
Answer in points:
1. And connect the POWER to THE DISPLAY BOARD not the raspberry board - how it works now?
2. What kernel you are using - stock=original , or kedei (this one is old and may not work)...
3. Install clean latest raspbian on sdcard - don't config anything (except ssh if you want), and see if you'll see desktop on display.

For now, with info that you provided: this looks like the display is bad or the connection to the display (from the HDMI chip to the display panel itself) at lest.

Krot wrote:
Sun Oct 15, 2017 10:10 am
Do I need to replace the entire configuration file?
Or below to add your code?
This is WHOLE file - config only is for fixing the high resolution to display native resolution (480x320px), not for touch.


This is about end of my abilities to help you remotely. Your best option would be just find some IT (or somebody who have knowledge about electronics and/or embedded computers/single board computers (SBC) like RPi) who would test your display at least.

Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sun Oct 15, 2017 12:07 pm

After feeding power through the screen, the emblem flashed and again the screen went out (
It is worth this version of the kernel: 2017-07-05-raspbian-jessie, 4.34 Gb

Krot
Posts: 9
Joined: Sun Oct 08, 2017 3:08 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sat Oct 21, 2017 1:19 pm

And how do I specify a link to the driver in the command line.
That they can be downloaded from the site of KeDei, maybe it will work.

Clemens500
Posts: 4
Joined: Wed Jan 18, 2017 6:49 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Mon Jan 08, 2018 5:19 am

Hi guys and girls,
has anybody used this screen with the openGL desktop driver (vc4) with its native resolution 480x320? The screen doesn't give the 480x320 resolution via the EDID to the driver. So with the openGL (VC4) Driver I can not choose this resolution.
If i add the resolution using the method described here (https://wiki.archlinux.org/index.php/xrandr) it gives me a black screen. :(
Would be great if someone could test it.

how to reproduce:
1. run raspbian stretch with desktop image
2. raspi-config --> advanced options --> GL driver --> first option
3. try to set resolution to 480x320 ??

flightrisk
Posts: 6
Joined: Mon Nov 07, 2016 8:05 am

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Wed Jan 24, 2018 10:34 pm

What's the latest on getting this to work? The display works well, but I can't quite get the touchscreen to get into the corners. First, all of you seem to have a completely different xinput than me. Perhaps this is due to the change from evdev to libinput? This is what I get when I run the calibration option off the menu from Pixel on a Raspberry Pi 3:

Code: Select all

Section "InputClass"
	Identifier	"calibration"
	MatchProduct	"ADS7846 Touchscreen"
	Option	"MinX"	"21219"
	Option	"MaxX"	"21310"
	Option	"MinY"	"48264"
	Option	"MaxY"	"48810"
	Option	"SwapXY"	"1"  # unless it was already set to 1
	Option	"InvertX"	"0"  # unless it was already set
	Option	"InvertY"	"0"  # unless it was already set
EndSection
It doesn't give me a matrix at all and there is no "Option 'Calibration'" setting. Do I have a different version of xinput_calibrator? No matter where I put these settings (currently I am using /usr/share/X11/xorg.conf.d/99-calibration.conf) it makes no difference at all. It does not swap X and Y, invert, etc. Only when I put THIS in the file will it work:

Code: Select all

Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ADS7846 Touchscreen"
        Option "TransformationMatrix" "0 1 0 -1 0 1 0 0 1"
        Option  "Calibration"   "90 3925 174 3968"
        Option  "SwapAxes"      "0"
EndSection
It seems to like "SwapAxes" instead of "SwapXY" and "InvertX", but it doesn't quite reach into the corners. I can't reliably select the start menu or the eject button in the lower right. Here is the boot log:

Code: Select all

[     8.512] (II) config/udev: Adding input device ADS7846 Touchscreen (/dev/input/event3)
[     8.512] (**) ADS7846 Touchscreen: Applying InputClass "libinput touchscreen catchall"
[     8.512] (**) ADS7846 Touchscreen: Applying InputClass "calibration"
[     8.512] (II) LoadModule: "libinput"
[     8.512] (II) Loading /usr/lib/xorg/modules/input/libinput_drv.so
[     8.538] (II) Module libinput: vendor="X.Org Foundation"
[     8.538] 	compiled for 1.19.0, module version = 0.23.0
[     8.538] 	Module class: X.Org XInput Driver
[     8.538] 	ABI class: X.Org XInput driver, version 24.1
[     8.538] (II) Using input driver 'libinput' for 'ADS7846 Touchscreen'
[     8.538] (**) ADS7846 Touchscreen: always reports core events
[     8.538] (**) Option "Device" "/dev/input/event3"
[     8.539] (**) Option "_source" "server/udev"
[     8.540] (II) input device 'ADS7846 Touchscreen', /dev/input/event3 is tagged by udev as: Touchscreen
[     8.541] (II) input device 'ADS7846 Touchscreen', /dev/input/event3 is a touch device
[     8.600] (**) Option "config_info" "udev:/sys/devices/platform/soc/3f204000.spi/spi_master/spi0/spi0.0/input/input3/event3"
[     8.600] (II) XINPUT: Adding extended input device "ADS7846 Touchscreen" (type: TOUCHSCREEN, id 6)
[     8.600] (**) Option "AccelerationScheme" "none"
[     8.600] (**) ADS7846 Touchscreen: (accel) selected scheme none/0
[     8.600] (**) ADS7846 Touchscreen: (accel) acceleration factor: 2.000
[     8.600] (**) ADS7846 Touchscreen: (accel) acceleration threshold: 4
[     8.600] (**) Option "TransformationMatrix" "0 1 0 -1 0 1 0 0 1"
[     8.602] (II) input device 'ADS7846 Touchscreen', /dev/input/event3 is tagged by udev as: Touchscreen
[     8.602] (II) input device 'ADS7846 Touchscreen', /dev/input/event3 is a touch device
[     8.603] (II) config/udev: Adding input device ADS7846 Touchscreen (/dev/input/mouse1)
[     8.603] (**) ADS7846 Touchscreen: Applying InputClass "calibration"
[     8.603] (II) No input driver specified, ignoring this device.
So it finds the "TransformationMatrix" setting, but it doesn't show loading 'option "calibration"', and indeed, says "no input driver specified, ignoring this device". This is very confusing, especially since everything basically works, I just need tweaks to get the calibration right so I can go all the way to the edges and corners.

I am confused by all the options. Is there a way to get xinput_calibrator to give me numbers I can use? Why don't MinX, MaxX work? Is there a formula for the "option calibration" numbers?

Me:
3.5" Display v 1.1
Raspberry Pi 3 model B
Raspian stretch 9 (latest standard version from Pi)

GAMELASTER
Posts: 38
Joined: Sat Feb 14, 2015 8:05 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Thu Jan 25, 2018 9:00 am

Try my calibrator, it works on latest Raspbian
viewtopic.php?f=38&t=203483
(Probably, I mistaken used evdev, when it's libinput, I will probably need to change the name :lol: )

vlykos
Posts: 2
Joined: Wed Jul 19, 2017 11:06 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Wed Jan 31, 2018 11:34 pm

So I cant get this screen to work I've tried downloading the driver I've tried downloading the whole raspbian image onto an SD card.. and a few of them worked but as so as I did one thing on it it stopped working and now it's just a blank white screen doesn't even say no signal it does nothing except a white screen

strahlemann0
Posts: 1
Joined: Thu Feb 01, 2018 12:43 am

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Thu Feb 01, 2018 1:22 am

After fiddling for a while, trying evdev without success and much more, this works for me:

Latest Raspian (today is the 1. Feb. 2018) with libinput for touchscreens. No evdev, no xinput_calibrator.

Create the file: sudo touch /usr/share/X11/xorg.conf.d/99-calibration.conf

Populate that file with a Transformation Matrix for 90° Right turn and Calibration Matrix using some Information from wikipedia and some brain to fast find good try out values ( took me three turns):

For calibration we have to scale (larger to reach the corners) and to translate (shift half of the enlargement towards the origin).

My "99-calibration.conf" looks like this and gives me movement straight into every edge:

Code: Select all

Section "InputClass"
    Identifier		"calibration"
    MatchProduct	"ADS7846 Touchscreen"
    Option	"TransformationMatrix"	"0 1 0 -1 0 1 0 0 1"
    Option	"CalibrationMatrix"  "1.15 0 -0.075 0 1.1 -0.05 0 0 1"
EndSection


The entire /boot/config.txt for completeness:

Code: Select all

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

hdmi_cvt=480 320 60 6 0 0 0
hdmi_group=2
hdmi_mode=87

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# For KeDei Touchcontroller
dtparam=spi=on
dtoverlay=ads7846,cs=0,penirq=25,speed=10000,penirq_pull=2,xohms=150

# Uncomment this to enable the lirc-rpi module
#dtoverlay=lirc-rpi

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on
Hope this helps.

Best regards.

User avatar
saper_2
Posts: 232
Joined: Sun Aug 03, 2014 10:08 am
Location: PL

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Fri Feb 23, 2018 5:01 pm

Clemens500 wrote:
Mon Jan 08, 2018 5:19 am
Hi guys and girls,
has anybody used this screen with the openGL desktop driver (vc4) with its native resolution 480x320? The screen doesn't give the 480x320 resolution via the EDID to the driver.
EDID - I think it's too advanced for kedei :lol: :lol: , joke aside - normally display driver pick the highest resolution it can support with display, this might be a reason that u can't get native res.
Clemens500 wrote:
Mon Jan 08, 2018 5:19 am
So with the openGL (VC4) Driver I can not choose this resolution.
If i add the resolution using the method described here (https://wiki.archlinux.org/index.php/xrandr) it gives me a black screen. :(
Would be great if someone could test it.

how to reproduce:
1. run raspbian stretch with desktop image
2. raspi-config --> advanced options --> GL driver --> first option
3. try to set resolution to 480x320 ??
I don't have spare uSD card to test... and I'm now into writing driver in python for eink (red/black/white :twisted: )
You didn't mention at all if u configured this display in config.txt file :?: :?: :?: :?: :?:

Clemens500
Posts: 4
Joined: Wed Jan 18, 2017 6:49 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Mon Mar 05, 2018 5:15 pm

You didn't mention at all if u configured this display in config.txt file :?: :?: :?: :?: :?:
No, I didn't because with the new openGL desktop driver (vc4) you dont need to configure the display resolution etc in the config.txt. It is done using linux tools like xrandr. And it works fine except from the native resolution 480x320 wich is a bummer :(

User avatar
saper_2
Posts: 232
Joined: Sun Aug 03, 2014 10:08 am
Location: PL

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Thu Mar 08, 2018 8:56 pm

Hi,

Hmmm...
I toyed a bit with this GL driver (in Full KMS), and I think I figured it out, but I'll wait few days before I'll publish my solution, because I want to see if this can be done prettier (right now somehow I don't like how I did this ;) )
See demo, pay attention to size of desktop elements:
https://youtu.be/mCWVoIqLA1E

---------- EDIT -------------
Clemens500 Check the paragraph 8.6 in 2nd post of this topic :) , I have added a fix for GL driver to run the display in native resolution

Clemens500
Posts: 4
Joined: Wed Jan 18, 2017 6:49 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Thu Mar 22, 2018 8:54 pm

@saper_2
wow. thank you very much!

usagi
Posts: 2
Joined: Wed Jun 13, 2018 12:02 am

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Wed Jun 13, 2018 12:19 am

Hey, The instuctions work fine but I having trouble with corner of the screen either I have to push hard or doesnt react.
The are so many different anwsers tried a few but didnt do much I'm using kali on raspberry. Any suggestions?

juj
Posts: 26
Joined: Sat Nov 18, 2017 10:51 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Wed Jun 13, 2018 11:46 am

I got one of those KeDei 3.5" HDMI displays as well, and did a side by side comparison video of it versus Adafruit's 2.8" PiTFT running fbcp-ili9341.

You can find the video here: https://www.youtube.com/watch?v=1yvmvv0KtNs

It's a pretty neat little display (both of them)! I was surprised though that it did not have vsync. Does anyone have a 3.5" HDMI display that does tearing free updates, or I wonder if vsyncless updates are the norm on displays in this size category?

floppes
Posts: 1
Joined: Sat Jun 16, 2018 3:35 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sat Jun 16, 2018 4:18 pm

The logo is located in the firmware at 0x260D8 - 0x2645F. It is encoded with a variable length coding, the table is in the first 8 bytes.

I wrote a GUI tool to easily replace the logo together with an Arduino sketch. The Arduino is used as an I²C master to read and write the firmware.

You can find the sources here: https://github.com/floppes/RTD266xFlash

Sana21
Posts: 8
Joined: Thu Apr 05, 2018 3:55 pm

Re: [Review] KeDei 3.5" HDMI display with touch for Raspberry Pi

Sun Aug 19, 2018 1:36 pm

From where did you download the LCD file? The official website has a lot of links. I have the same LCD. And also where did you save the config.txt file? Did you make it or it was already there and you just edit it? I am confused :cry:

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