MultiTouch Touchscreen for OpenCPN

[LJK]

Hello,
Any recommendations for a (cheap) 7inch touchscreen, with multi touch support (picnch to zoom, long press to right click), for use with a Raspberry Pi and OpenPlotter?

Installation in wheelhouse so no waterproofing or daylight display requirements, but if it is possible at this stage of Raspbian / OpenPlotter development I would very much like to have multi touch support.

The obvious candidate is the Official RaspberryPi touchscreen, but is the screen’s multitouch supported in OpenCPN?

Thanks,

[mikedefieslife]

Its the operating system that needs to support multi-touch, openCPN will work with whatever inputs it picks up from the OS.

[LJK]

Have purchased the "Official Rapberry Pi Touchscreen".
Fresh install of Raspbian Buster.
OpenCPN v5.
$lsmod shows that the hid-multitouch kernel module is installed.
OpenCPN/options/UI/enable touchscreen is checked.
Touch screen works as a single click device, but multi touch (and so pinch and zoom) do not.
Does anyone have this working!?
thanks,

[Hakan]

LJK..
I've the "official" Raspberry 7" screen on a RPi3B+ and O v 5.0.
I can confirm your observations. Single click and drag is working. Double or long click is not working. Two finger zoom in/out is not working in OCPN, with or without "[]Enable touchscreen", although I can two finger zoom in for example Chromium browser.
I haven't tested this before so I've no advises to share.

[LJK]

thanks Hakan - so I wonder, has anyone else made it work?

[Alexandros]

I use the daemon "twofing". It uses two fingers touch for right click and includes pinch-expand gestures.


Look at https://www.raspberrypi.org/forums/v...c.php?t=138575 for some details on how to install


Alexandros

[LJK]

Much appreciation for the info. I followed the above link and have it working.
Superb help. Thankyou.

[mgrouch]

Originally Posted by mikedefieslife

Its the operating system that needs to support multi-touch, openCPN will work with whatever inputs it picks up from the OS.

It doesn't seem the case. Multitouch works for me in Chromium on latest Raspbian, but it doesn't work in OpenCPN. Seems something is not complete

in OpenCPN. In Chromium I can zoom in/out with two fingers with no issues.


Has anyone from OpenCPN dev team looked at how its done in Chromium?


Thanks,
--MG

[LJK]

I concur.
OpenCPN does not seem to support multi touch, unless the twofing daemon workaround is applied to it.

[CatNewBee]

It seems to not respond to the multi-touch zoom events as the raspbean OS does. Implementation of doubleclick and context menu are difficult too with touch.

[flatman]

I was pulling my hair out the last couple days trying to get OpenCPN to work with a USB Touchscreen on a RPI4 Raspbian Buster. The touchscreen I'm using is a Uperfect 12.3" 1600x1200 10 finger touch. $100 on ebay. Works beautifully with the Chrome browser. Great website to test multi-touch is https://patrickhlauke.github.io/touch/

However, no luck getting pinch to zoom and right mouse click emulation to work in OpenCPN. I did finally get right click working by switching the X11 driver from libinput to evdev but evdev had calibration issues I never totally figured out.

I was able to get the twofing workaround up and running. The Uperfect reports as a "TSTP MTouch". Pretty much followed the instructions for Buster substituting "TSTP MTouch" for "FT5406 memory based driver". And creating a rule file /etc/udev/rules.d/libinput.rules instead of /etc/udev/rules.d/70-touchscreen-egalax.rules

The twofing workaround kind of breaks some of the touchscreen stuff for the Chrome browser. I'm planning on using this primarily for OpenCPN so the loss of touch functions in other apps is not a real problem for me right now. The twofing workaround for OpenCPN seems a bit sluggish compared to the stock multi-touch in the Chrome browser.

There are also some tricks for hiding the mouse cursor to make things look more tablet like. I've edited /etc/lightdm/lightdm.conf adding the line xserver-command = X -nocursor". I may switch to the utility unclutter as you can set up rules to get the cursor back when you plug in a real mouse.

In general OpenCPN works just OK with a touchscreen. Deleting waypoints, tracks and such with touch is a bit tricky. Hitting the right tabs, buttons and such is a little tricky too with fat fingers.