ELO Touchscreen monitor under Linux

*Edit* I have updated this to no longer require you to edit xorg.conf. This also fixes issues if the touchscreen’s usb cable is hotplugged while X is already running.

I recently purchased an ELO 1537L 15-inch open-frame touchmonitor for a project I am doing at work.  I have successfully gotten the touchscreen monitor to work under linux (specifically Scientific 6.x) using USB (I haven’t tried the serial interface).  Plugging in the monitor, it is recognized as a 5020 Surface Capacitive:


19746:Aug 3 02:51:13 localhost kernel: usb 2-1: Product: Elo TouchSystems Surface Capacitive 5020
19747:Aug 3 02:51:13 localhost kernel: usb 2-1: Manufacturer: Elo TouchSystems
19750:Aug 3 02:51:13 localhost kernel: input: Elo TouchSystems Elo TouchSystems Surface Capacitive 5020 as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1:1.0/input/input7
19751:Aug 3 02:51:13 localhost kernel: generic-usb 0003:04E7:0042.0003: input,hidraw2: USB HID v1.11 Pointer [Elo TouchSystems Elo TouchSystems Surface Capacitive 5020] on usb-0000:00:1d.0-1/input0

ELO provides some generic drivers for this device. I first attempted to directly use them and found them to be a complete disaster. The whole configuration was really silly (putting stuff into /etc/opt, are you kidding me?). The elo daemon constantly hung and had to be restarted. Restarting X caused the daemon to stop working, thus the touchscreen stopped working.

I quickly removed these drivers and tried it with the evtouch drivers which I have used for a USB displaylink touchscreen monitor in the past (MIMO). With a few changes to my xorg.conf, the evtouch driver immediately recognized it and I was able to capture touch events. Although the calibration was initially completely off.

Here’s the steps I took to get this working on Scientific Linux 6.0

Install evtouch

Unfortunately, Scientific Linux does not come with the evtouch driver. I have built a 64-bit rpm for Scientific Linux here . If you need a 32-bit version or for another platform (Fedora), download the src rpm and rebuild it (rpmbuild –rebuild xorg-x11-drv-evtouch-0.8.8-1.el6.src.rpm).

Setup Xorg

It is not required to directly edit xorg.conf. Instead, we will create a hal fdi file

We will create an fdi file in /etc/hal/fdi/policy called elo_touchscreen.fdi

/etc/hal/fdi/policy/elo_touchscreen.fdi

<?xml version="1.0" encoding="ISO-8859-1"?>
<deviceinfo version="0.2">
<device>
<match key="input.product" contains="Elo TouchSystems, Inc. Elo TouchSystems Surface Capacitive 5010">
<merge key="input.x11_driver" type="string">evtouch</merge>
<merge key="input.x11_options.MinX" type="string">3724</merge>
<merge key="input.x11_options.MaxX" type="string">318</merge>
<merge key="input.x11_options.MinY" type="string">3724</merge>
<merge key="input.x11_options.MaxY" type="string">318</merge>
<merge key="input.x11_options.SwapX" type="string">true</merge>
<merge key="input.x11_options.SwapY" type="string">true</merge>
</match>
</device>
</deviceinfo>

If your monitor is slightly different, you will need to get the product id, and replace the match key=”input.product” line in the above file.


$ lshal | grep input.product
input.product = 'Sleep Button' (string)
input.product = 'Power Button' (string)
input.product = 'Macintosh mouse button emulation' (string)
input.product = 'ImExPS/2 Generic Explorer Mouse' (string)
input.product = 'AT Translated Set 2 keyboard' (string)
input.product = 'Elo TouchSystems, Inc. Elo TouchSystems Surface Capacitive 5010' (string)

You should now be able to unplug and plug your touchscreen back in and have it work without restarting X

Calibration

The MinX,MinY,MaxX,MaxY values are used for calibrating the touchscreen. The evtouch source available on their site comes with a calibration utility. However, I was unable to get this to run. For me I played with the MinX, MaxX, MinY, MaxY values in my xorg.conf until it was close enough. As you can see, I had to mirror both the X and Y values.

Other Drivers

I noticed that Scientific Linux also includes an elographics package: xorg-x11-drv-elographics. I have no idea if this works better or not although I have heard they only work with the serial interface. I have it working with evtouch, so I’m happy. If anyone has tried the elographics and had success, please comment!