Converting a generic tablet to use as an external display

RavenLunatic

RavenLunatic

RavenLunatic

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How about this for random idea
:-)
possibly too random for the random thread!

I have an old Android 11 Teclast_T40_Plus_eea Tablet that stopped getting updates years ago.

I would like to repurpose it as an extended display for my computer.

I want to control the Tablet with my computers keyboard and mouse just like I would with an external monitor.

I have not been able to find anything like Synergy to do so on the google play store in android.

I had the Idea that I could unlock the boot loader and install an ARM64 version of Debian or Ubuntu on it instead as there is a Synergy V1 ARM64.deb file I could use.

So far I have been able to use adb and fastboot commands to access recovery mode but have been unable to get it to boot from OTG USB or SD card with ISO installer for ARM64.

My question is, what I am trying to do a thing, and is it possible to put a mainstream Linux OS on a generic tablet?

What do you think?
 
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If extended display is the goal, you'd probably find it easier to remove the display from the tablet, or at least get it open, so that you can buy some kind of display converter if it exists to allow you to attach the display to the converter by the ribbon cable, then attach your computer to the converter.

A software-based solution using the tablets own hardware probably isn't that easy and likely won't work great, especially if it's old. Sounds like a rabbit hole of pain and frustration to me. Unless you actually want to and are capable to develop the software, but it doesn't make much practical sense.

Having said all of the above, I'd probably go the route of recycling the tablet and getting a monitor or separate display. They can be had so cheap now, not much more than a display converter. E.g. second hand even.
 
I can't remember what it was, but there was definitely an app I used to have on my Android tablet that allowed it to be used as an external monitor. It was something I installed from the Play store (not free). I've just looked on the Play store and there do seem to be multiple apps that do this.
 
I was just about to brick the tablet by flashing an Ubuntu.img to the system partition.:-)

I have looked on the play store and the apps I can see are controlling a computer with a tablet/phone rather than the other way around.

When I search for extend desktop on the play store there are quite a few apps but are for Mac or PC only.

I have looked into various VNC implementations but they seem to want to display a window of the tablet on my monitor which I do not want.

Quite like the idea of some of them being able to use the touch screen.
 
Yeah you can use an android tablet as
Another display/monitor
I use an old 10 inch yoga tab and display
All my system temps,fan speeds etc on it
Useful as the yoga tab has a built in metal kickstand
And this things ancient only android 6
But still works

Edit
The software to use it as
Another monitor/display is called spacedesk it's free
On playstore and windows version has a website
Can do either over usb
Or a WiFi connection to the tablet
Mouse definitely works on the tablet /external display
Though the difference in resolution and possibly the old android hardware
Does mean the mouse is a bit slower to respond
Than on the main display

There's also free software called odosoft remote panel
Though I only tested that one as far as
Using it to display stats from aida64 on the tablet
Didn't test other functionality

Touchscreen still works too
On my android tablet anyway only tested on
A couple android devices

The putting Linux bit on there may be possible
But I haven't messed around with that sort of thing
In a very long time
 
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Mcnumpty2323 said:
Yeah you can use an android tablet as
Another display/monitor
I use an old 10 inch yoga tab and display
All my system temps,fan speeds etc on it
Useful as the yoga tab has a built in metal kickstand
And this things ancient only android 6
But still works

Edit
The software to use it as
Another monitor/display is called spacedesk it's free
On playstore and windows version has a website
Can do either over usb
Or a WiFi connection to the tablet
Mouse definitely works on the tablet /external display
Though the difference in resolution and possibly the old android hardware
Does mean the mouse is a bit slower to respond
Than on the main display

There's also free software called odosoft remote panel
Though I only tested that one as far as
Using it to display stats from aida64 on the tablet
Didn't test other functionality

Touchscreen still works too
On my android tablet anyway only tested on
A couple android devices

The putting Linux bit on there may be possible
But I haven't messed around with that sort of thing
In a very long time
Click to expand...
Thanks for the tips!

Unfortunately odosoft remote panel is too old and It hasn't been updated for 10 years and does not support any of my devices.

Spacedeck looks really good but its for Windows only despite having Windows ARM support, talk about niche! I would have thought there are more Linux computers than ARM Windows ones.

The tablet is effectively e-waste anyway I might just flash it, Kill or Cure as they say!
 
RavenLunatic said:
Thanks for the tips!

Unfortunately odosoft remote panel is too old and It hasn't been updated for 10 years and does not support any of my devices.

Spacedeck looks really good but its for Windows only despite having Windows ARM support, talk about niche! I would have thought there are more Linux computers than ARM Windows ones.

The tablet is effectively e-waste anyway I might just flash it, Kill or Cure as they say!
Click to expand...
Yeah not much to lose really
Not sure as not messed around with it in years
But xda forums may have a Linux section
Though no idea which devices they cover putting Linux
On in there
Think that's where I used to get custom roms and stuff from
Though my memory isn't great in my old age
Probably forgotten more than I remember now lol
 
Tried to flash the system and boot partitions but got an error insufficient space trying to install Ubuntu_arm64.img which was 3.9GB. Tried to install a much smaller debian-12.10.0-arm64-netinst.img 560MB and got a FAILED (remote: 'Flashing Lock Flag is locked. Please unlock it first!'

Turns out I had not unlocked the boot loader just the permissions to do it.

Followed this thread and its now properly unlocked..

in case anyone in the future sees this thread be advised your must run the modified fastboot executable from the download link and that the last command took 10min to confirm the device is unlocked in terminal not the 85 second example in the thread.

I might brick it yet, but not today!
 
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Infinite boot loop...

It was expected, however all I was doing was trying to root the device. must have had the wrong boot.img and vbmeta.img files.

Device refuses to go into fastbootd or recovery so I cant try other firmware, however duckduckgo AI suggests leaving it on for a few hours and it may go into recovery mode by itself.

Its a shame Android devices are so locked down, as my tablet would have been really useful if I could install a proper OS on it.

All in all I was not able to find a guide to install Linux on an Android device, and now this thread is top of the search results lol

Time to move on.
 
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It lives!

I was able to re-flash the tablet once the battery ran out. The boot loop would not let me turn the device off.

The manufacturer has an image flashing tool to restore the device from a .PAC file, and luckily the boot loader remains unlocked.

The tool was Windows only, but it worked with my Windows 11 virtual machine. With a little computer gymnastics to pass through the USB device, connecting the USB cable, driver and flashing programme in the right sequence to talk to each other at the same time.

It would be good if i could find a rooted .PAC file.

Time to try again :-)
 
I have found a video that uses VNC within the android device which is kind of what I want, but the UI does not scale very well.

On the plus side I do not need to have the tablet rooted.


I can apt install gdm3 but it always returns to XFCE on reboot which is annoying.

There also is no app repository for some reason.

In any case my aim is to get Linux to run natively
 
Problem (almost) solved

It turns out Gnome has a desktop sharing setting>system>remote desktop>desktop sharing

It only works with Wayland. I thought Wayland was the default for long enough but apparently my install was x-org.

It enables a virtual display that you can move around like a real monitor and even supports scaling at 200%


Things that need some work.

Mouse pointer is invisible on the virtual display but it can interact with objects on it.

Wi-Fi connection is flaky and it freezes up too often.

When the connection fails it logs you out of computer which is a frequent problem on 5Ghz. Trying again with 2.4Ghz to see if its any better. It should be flawless as my WiFi access point is 4 feet away.

I am going to investigate to see if there is a USB communication option.

I still would like to somehow get a real distro on the tablet but I don't think that is going to happen anytime soon.

Edit: It just stuck me USB communication option < Ethernet mind blown lol :-)
 
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I have managed to root my Teclast T40 EEA M7T3

Warning this will erase all of the user data and files on the Tablet!

Turn on the Tablet.

The process requires the use of SPDResearchTool and drivers

Unfortunately, the tool only works in Windows despite my best efforts I could not get it to work in a virtual machine so had to do this on bare metal Windows install.

Download the pac file from the Teclast website,

Run the SPDResearchTool and load the pac file this will extract all the files that are contained in the pac file to a folder called ImageFiles in the same directory as the SPDResearchTool. This will take some time since the largest file in the pac file is 4GB in size. once done it will display the details of the firmware at the top of the SPDResearchTool.

Swap out the boot.img and vbmeta.img with the modified ones within the ImageFiles folder.

Connect the tablet to the computer and press the play button on the SPDResearchTool

Then turn the tablet off as the SPDResearchTool only works with the tablet once it is fully off. I had the probem with the tablet going into charging mode breaking the connection when commanded to turn off.

You may need to turn it off and on again a couple of times bit eventually it will connect with the SPDResearchTool and the download onto the tablet will begin.

Once the download process is over, turn the Tablet back on and if all gone well you will boot into Android setup.

After you configure the settings look for a programme called Magisk and click on it. Follow the on screen commands and a quick reboot and you are done.

To confirm Download the temrinal program Termux for android.
Type SU and enter
You will now be promted to give permission :-)

A big shout out to https://xdaforums.com as I could not have done this without you!
 
RavenLunatic said:
How about this for random idea
:-)
possibly too random for the random thread!

I have an old Android 11 Teclast_T40_Plus_eea Tablet that stopped getting updates years ago.

I would like to repurpose it as an extended display for my computer.

I want to control the Tablet with my computers keyboard and mouse just like I would with an external monitor.

I have not been able to find anything like Synergy to do so on the google play store in android.

I had the Idea that I could unlock the boot loader and install an ARM64 version of Debian or Ubuntu on it instead as there is a Synergy V1 ARM64.deb file I could use.

So far I have been able to use adb and fastboot commands to access recovery mode but have been unable to get it to boot from OTG USB or SD card with ISO installer for ARM64.

My question is, what I am trying to do a thing, and is it possible to put a mainstream Linux OS on a generic tablet?

What do you think?
Click to expand...

Just easier to get one like this?

 
hornetstinger said:
Just easier to get one like this?

Click to expand...

I know I could just buy a £20 monitor.

My aim is to transform my old Tablet into something useful without spending any money, and at the same time saving it from becoming e-waste.

Once I get an idea in my head I have to see if it is possible.

And Linux has shown me that more often than not it is.
 
I am getting close

I need to boot Ubuntu from the phones boot menu using the command

fastboot boot /path/to/linux.iso

Having a problem pointing the command to where I saved the iso.

I have saved the file to the phones Download folder as well as an external SD Card.

I have tried the following paths

********@Ubuntu-PC1:/$ fastboot boot /storage/emulated/0/Download/plucky-desktop-arm64.iso
fastboot: error: cannot load '/storage/emulated/0/Download/plucky-desktop-arm64.iso': No such file or directory

********@Ubuntu-PC1:/$ fastboot boot T40_Plus_EEA:/storage/emulated/0/Download/plucky-desktop-arm64.iso
fastboot: error: cannot load 'T40_Plus_EEA:/storage/emulated/0/Download/plucky-desktop-arm64.iso': No such file or directory

********@Ubuntu-PC1:/$ fastboot boot /storage/77AD-53CE/plucky-desktop-arm64.iso
fastboot: error: cannot load '/storage/77AD-53CE/plucky-desktop-arm64.iso': No such file or directory

********@Ubuntu-PC1:/$ fastboot boot /mnt/sdcard/Download/plucky-desktop-arm64.iso
fastboot: error: cannot load '/mnt/sdcard/Download/plucky-desktop-arm64.iso': No such file or directory

********@Ubuntu-PC1:/$ fastboot boot T40_Plus_EEA:/storage/sdcard0/plucky-desktop-arm64.iso
fastboot: error: cannot load 'T40_Plus_EEA:/storage/sdcard0/plucky-desktop-arm64.iso': No such file or directory

********@Ubuntu-PC1:/$ fastboot boot T40_Plus_EEA:/storage/emulated/0/Download/plucky-desktop-arm64.iso
fastboot: error: cannot load 'T40_Plus_EEA:/storage/emulated/0/Download/plucky-desktop-arm64.iso': No such file or directory

********@Ubuntu-PC1:/$

For the file saved in the download folder:

adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
T40_Plus_EEA:/ $ dir
/system/bin/sh: dir: inaccessible or not found
127|T40_Plus_EEA:/ $ ls
acct cache data_mirror etc init.recovery.ums512_1h10.rc linkerconfig odm product system
apex config debug_ramdisk init init.recovery.ums512_1h10_go.rc lost+found oem sdcard system_ext
bin d default.prop init.environ.rc init.recovery.ums512_20c10.rc metadata postinstall storage vendor
bugreports data dev init.recovery.common.rc init.recovery.ums512_2h10.rc mnt proc sys
T40_Plus_EEA:/ $ cd storage
T40_Plus_EEA:/storage $ ls
77AD-53CE emulated sdcard0 self
T40_Plus_EEA:/storage $ cd emulated
T40_Plus_EEA:/storage/emulated $ ls
0
T40_Plus_EEA:/storage/emulated $ cd 0
T40_Plus_EEA:/storage/emulated/0 $ ls
Alarms Android Audiobooks DCIM Documents Download Movies Music Notifications Pictures Podcasts Ringtones
T40_Plus_EEA:/storage/emulated/0 $ cd Download
T40_Plus_EEA:/storage/emulated/0/Download $ ls
plucky-desktop-arm64.iso
T40_Plus_EEA:/storage/emulated/0/Download $


For the file saved to SD card:

T40_Plus_EEA:/ $ ls
acct cache data_mirror etc init.recovery.ums512_1h10.rc linkerconfig odm product system
apex config debug_ramdisk init init.recovery.ums512_1h10_go.rc lost+found oem sdcard system_ext
bin d default.prop init.environ.rc init.recovery.ums512_20c10.rc metadata postinstall storage vendor
bugreports data dev init.recovery.common.rc init.recovery.ums512_2h10.rc mnt proc sys
T40_Plus_EEA:/ $ cd sdcard
T40_Plus_EEA:/sdcard $ ls
Alarms Android Audiobooks DCIM Documents Download Movies Music Notifications Pictures Podcasts Ringtones
T40_Plus_EEA:/sdcard $ cd Download
T40_Plus_EEA:/sdcard/Download $ ls
plucky-desktop-arm64.iso
T40_Plus_EEA:/ $

Can anyone take a look?
Its probably a syntax error on my part, but its got me stumped

Edit: Found the problem fastboot requires the file to be on your computer, not on the device itself.
Tried booting from my computer and it said the Ubuntu image was too big. Tried a Netinst of debian which uploaded, but just loaded android when executed.
 
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I have failed :-(

I was not able to find a .pac file to turn the tablet into a full desktop environment, only one to root. Installing an ISO in aarch64 is not as simple as on x86_64.

Running on bare metal aarch64 has proved impossible. I spent far too much time trying to configure Limbo ARM Emulator (QEMU), but for some reason perhaps the SoC of my tablet I never managed to get any ISO or even the UEFI to post.

There are a number of apps that claim to provide a way to run a desktop, usually on top of Termux, but they are slow, or don't allow for additional packages to be installed. On rare occasions they will allow it, but it is not persistent, and will disappear after rebooting. Most rely on VNC which only makes things slower and with terrible graphics. Some even charge in app for additional functionality years after they where last updated.

Interestingly I was able to run a x86_64 Linux on the tablet but is was painfully slow even with the most efficient of distros via Limbo PC Emulator (QEMU).

I have also tried to create a virtual machine using QEMU directly from Termux and another terminal programme but it just freezes up with no output, forcing me to kill the process.

After all that, I am still interested in having an additional small screen to my setup.

Since I cannot save my old tablet from becoming e-waste I am going to save another from the same fate.

I have picked up a renewed Surface Go from 2018 that should work 100%. I own a Surface Pro 7 from about the same time which works just fine with the exception of the camera.
 
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