Acer T232HL and multi-touch support in Raspbian

[SCPRedMage]

I'm working on a project requiring a larger multi-touch monitor, and I'm using a 23" Acer T232HL, but Raspbian seems to be treating it as just a mouse. In other words, no touchscreen conventions like long-tapping, and no recognition of multiple touches; it just registers a left-click at the location of the first touch, complete with moving the mouse cursor there, and ignores other touches until the first one is released.

Unfortunately, my searching has found no definitive solution, despite multiple instances of people having this same problem with this same monitor. If anyone knows how to resolve the issue, I'd appreciate the help; otherwise, I'll report back here when I get it fixed, for others to use in the future.

[klricks]

I have a different monitor Hannspree HT231 (23" 10 pt multi) and it acts exactly as you describe. Single point acting like a mouse.
Though it's been awhile since I tried it.

[wadeconeybeer]

I am having same trouble with T232HL touchscreen. Any luck?

[Wing]

I too purchased an Acer T232HL. The touch screen does not work at all. SCPRedMage said you got it working like a mouse. That is all I need. Please post your settings. Thank you!

[klricks]

I too purchased an Acer T232HL. The touch screen does not work at all. SCPRedMage said you got it working like a mouse. That is all I need. Please post your settings. Thank you!

Did you connect the USB 'B' cable from monitor to RPi?

[Wing]

Yes the USB cable was plugged in. After trying a lot of different ideas I found in the forums, I finally got it to work. This is just the opposite of what I would have thought. I plugged the Acer T232HL Touch screen's USB cable into a USB hub and then plugged the USB hub into the Raspberry PI and the touch screen now works. The USB Hub is plugged into the same port (port 4) that the touch screen had been plugged into directly, only now that it is going through the USB Hub, it works. My guess is that the PI does not understand how to handle the touch screen plus built-in USB hub, but it does know how to hand the USB hub I plugged in and the USB hub I plugged in knows how to handle the touch screen and the other hub. I'm having to set this up for a clerk to use or I'd play with it more and provide more information. But for anyone having issues with getting the Acer T232HL Touch screen to be recognized, try plugging it into a USB hub and then into the PI.

[davidpuzey]

I have a T272HL, I have the same problem with multitouch, and I also had the same problem with the touchscreen not working.
I suspect the touchscreen not working thing is related to this: https://github.com/raspberrypi/firmware/issues/64
It looks like the internal USB3.0 hub is made by a company called Via, and they have had a bug in their implementation of USB 3.0 in other products. Other people managed to fix it with a firmware update, sadly there isn't one for the monitor, I contacted both Acer and Via about it a couple of days ago, so I'll see what they say.
The fix I used was to force USB to operate as if it were USB v1 (by adding

Code: Select all

dwc_otg.speed=1

into /boot/cmdline.txt, see the bug linked above for more info), which is a bit rubbish (stops my keyboard/mouse from working :/), I might try the hub idea instead.

As for multitouch, I noticed that when the driver registers it creates two devices (in /dev/input/), 'event0' and 'mouse0' (might be different for you guys, but probably not). I'm guessing it's using 'mouse0'.
If you use this on the command line

Code: Select all

hd /dev/input/event0

and try touching the screen, it happily chucks out a whole load of data, so it appears that the driver is receiving touch events okay. Just need to find a way to tell Linux it's want's the multitouch data rather than the mouse data ... possibly with xinput and xorg config.

It's not a solution, but it might be helpful for someone. I'll keep playing around, and if I find a solution I'll post it.

[SammyS]

Hello,

I too have an T232HL. Good value but of no use without it connected to a RPi with touch functionality. This is an important project I am working on for the NAIAS and would appreciate any help in getting these displays working, even if it operates as a mouse without the "10 point multi-touch".

I have tried the USB hub idea but no go. Any help would be greatly appreciated.

Sam

[blankname]

Hello,

I know that this is a very old thread, but, since it's one of the first results if you look for this monitor and Raspberry Pi on Google, I'll post the solution I found.

For the touch to work, the USB hub between the monitor USB port and the Raspberry has to be USB 1.1.
If it is 2.0 (or 3.0 despite it will be recognized as 2.0), the screen USB hub (manufactured by Via) will be recognized, but no USB 1.1 devices connected to that hub will work (the internal touchscreen controller is 1.1). It is shown in dmesg as a device that fails to enumerate.

If you enable USB charging while off on the screen, the Raspberry Pi can be powered by the screen. But you have to connect it to the two "normal" USB ports, not the USB dedicated charging port (I know it sounds strange, but it seems that connecting the power to that port and the upstream USB port, the one used for USB data, causes some kind of power cycle on the charging port).

I have tested this with a Pi 2 and a Pi 3. I don't know if the new Pi 3 B+ has a different USB behaviour.

Regards

[StanSimmons]

I've had good luck using the Belkin USB 1.1 4-Port Hub F5U045 with both the Acer 232Hl and 272HL to get around the buggy VIA USB 3.0 chipset when connecting to the Raspberry Pi 3B+.

[woodi888]

Fairly noobie here. Trying to get an Acer T230H touch screen working accurately. This forum has help greatly. I am using a Raspberry Pi model 3 B and an old USB 1 hub. I am having troubles calibrating the touch screen.

I have changed the /boot/config.txt file to include added 3 lines as follows
hdmi_group=2
hdmi mode=87
hdmi_cvt 1920 1080 60 0 0 0 0

I have a feeling it may have to do with this line in the config.txt :
#framebuffer_width=1280
#framebuffer_height=720

The calibration is spot on anywhere near the middle of the screen but is a couple inches off by the time touching near the edges of the screen.
Any recommendations would be greatly appreciated!

[dftmonteiro]

olá, eu tambem tenho o monitor acer t232hl e estpu com dificuldade em calibrar, ele deteta e funciona, mas não está bem calibrado.
alguém pode ajudar neste problema?
obrigado

[Mr.MarioBranco]

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