AVL MXE Linux and Touchscreens?

What other apps and distros do you use to round out your studio?

Moderators: MattKingUSA, khz

Post Reply
pax-eterna
Established Member
Posts: 106
Joined: Sat Apr 24, 2021 11:30 pm
Has thanked: 9 times
Been thanked: 6 times

AVL MXE Linux and Touchscreens?

Post by pax-eterna »

I have a touchscreen coming soon and I was wondering what support there is in AVL MXE Linux? Or indeed, Linux in general.

Thanks
j_e_f_f_g
Established Member
Posts: 2032
Joined: Fri Aug 10, 2012 10:48 pm
Been thanked: 357 times

Re: AVL MXE Linux and Touchscreens?

Post by j_e_f_f_g »

If it's a DisplayLink device (ie, both the touchscreen and video go over one USB cable), then you're probably going to have trouble.

If the video and touchscreen signals go over different cables, then things should be fine.

Author of BackupBand at https://sourceforge.net/projects/backupband/files/
My fans show their support by mentioning my name in their signature.

pax-eterna
Established Member
Posts: 106
Joined: Sat Apr 24, 2021 11:30 pm
Has thanked: 9 times
Been thanked: 6 times

Re: AVL MXE Linux and Touchscreens?

Post by pax-eterna »

It has both options - USB-C only and the combo you mentioned.
User avatar
milo
Established Member
Posts: 1242
Joined: Wed Sep 06, 2017 2:55 am
Location: Southern Utah, USA
Has thanked: 275 times
Been thanked: 218 times
Contact:

Re: AVL MXE Linux and Touchscreens?

Post by milo »

I have an all-in-one Dell Inspiron with a touchscreen, and the touchscreen has worked out of the box on every distro I have run on it over the years, including AVL-MXE. I think touchscreen support is baked into the kernel.
j_e_f_f_g
Established Member
Posts: 2032
Joined: Fri Aug 10, 2012 10:48 pm
Been thanked: 357 times

Re: AVL MXE Linux and Touchscreens?

Post by j_e_f_f_g »

milo wrote: touchscreen support is baked into the kernel.
It is if the touch device follows the Human Interface Device (HID) standard. Virtually all keyboards and mouse (including touchscreens do).

But DisplayLink is a proprietary protocol for transferring compressed video over a USB cable along with touchscreen data. It was created by a company that sells a chip which implements this protocol. They also make the Windows and OSX drivers for the chip. So if a company just wants to make a USB touchscreen, but not need to design all the hardware, and write drivers, they just license this chip from that manufacturer. Needless to say, the manufacturer does NOT publish the specs for their proprietary product. Someone reverse-engineered enough of the protocol to make a DisplayLink driver for Linux. But there are 2 problems:

1) It isn't a fully compatible/complete implementation. My experience with a number of DisplayLink devices by Lilliput, DoubleSight, and Mimo have shown the linux support to be unpredicatable at best. If the device works at all, the most common problem is that the mouse axis are reversed. So if you slide your finger up, the mouse cursor goes down. If you go left, it goes right. Etc. In other words, not practical to use.

2) There have been two versions of the DisplayLink protocol. The linux support seems to be limited to the older, first version chips. The newer chips are incompatible.

Author of BackupBand at https://sourceforge.net/projects/backupband/files/
My fans show their support by mentioning my name in their signature.

Drumfix
Established Member
Posts: 299
Joined: Mon Jan 26, 2009 5:15 pm
Been thanked: 11 times

Re: AVL MXE Linux and Touchscreens?

Post by Drumfix »

They provide a DisplayLink binary driver for Ubuntu here and notes on how to compile the opensource part for other distros:

https://www.synaptics.com/products/disp ... ads/ubuntu
j_e_f_f_g
Established Member
Posts: 2032
Joined: Fri Aug 10, 2012 10:48 pm
Been thanked: 357 times

Re: AVL MXE Linux and Touchscreens?

Post by j_e_f_f_g »

I tried the ubuntu driver. Didn't work at all with my devices.

Author of BackupBand at https://sourceforge.net/projects/backupband/files/
My fans show their support by mentioning my name in their signature.

Post Reply