Probably a very simple question, but I haven't had much luck finding a answer on my own. I have a Tontec 3.5" touchscreen plugged into my RPi2. Is there any way that I can use the touchscreen when there's no monitor attached, but if I plug an HDMI cable in, the video output changes from the touchscreen to the attached display? Any tips are appreciated.
asked Dec 23, 2015 at 23:34
-
You mean to use it like a mousepad (no image showing but still touch sensitive)? From a product description the TouchScreen and the LCD display BOTH use the SPI - I suppose that the touch-screen might work even if the LCD is not active but you seem to be saying not - or is it that you want to have both displays running at the same time?– SlySvenDec 24, 2015 at 21:23
Add a comment
|
2 Answers
You need to do two things :
1 Setup your xorg.conf with two layouts , HDMIOnly and TFTOnly. Use this as inspiration : https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=91764&start=25#p661085
2 Use a script to auto-switch between the two layouts. Try this:
#!/bin/bash
HDMI_ON = false
while true; do
if (/usr/bin/tvservice -s | /bin/egrep 'HDMI|DVI') ; then
if [ ! "$HDMI_ON" = true ] ; then
/usr/bin/pkill X
/usr/bin/startx --layout HDMIOnly
$HDMI_ON = true
fi
else
if [ "$HDMI_ON" = true ] ; then
/usr/bin/pkill X
/usr/bin/startx --layout TFTOnly
$HDMI_ON = false
fi
fi
sleep 1
done
answered Jan 13, 2016 at 7:54
You can do what i did, and it works fine, i have a raspberry pi official 7 inch touchscreen, i connected a switch to the power pin of the touchscreen(powered through GPIO), so whenever i have to switch between displays, i just power off or on the switch, and then reboot the pi. I know this is a little manual labour but still it works very smoothly, if you want only one display at a time.
