I have a Raspberry Pi 3 running Raspbian Jessie with a PiTFT 2.8" resistive screen. Everything is working great, except that the resolution is not optimal; icons and text are too big for the screen to be 100% useful.
I tried different things, so far nothing worked.
First thing I tried was to change resolution related parameters in
# uncomment to force a console size. By default it will be display's size minus # overscan. framebuffer_width=640 framebuffer_height=480
With no effect. I tried another strategy, still playing with
/boot/config.txt, following what I read here:
# uncomment to force a specific HDMI mode (this will force VGA) hdmi_force_hotplug=1 hdmi_cvt=320 240 60 1 0 0 0 hdmi_group=2 hdmi_mode=87
With no effect.
I changed strategy again, following some leads on the Xorg side. First, I saw what I could do with
~$ DISPLAY=:0 xrandr --dpi 60
That returns an error:
xrandr: Failed to get size of gamma for output default
I read somewhere else that one could also change it through
FRAMEBUFFER=/dev/fb1 sudo startx -- -dpi 30
With no effect (X restart, but everything stays the same). I then tried to modify some things in Xorg configuration (following this lead), adding to
/etc/X11/xorg/conf.d/99-calibration.conf the following lines:
Section "Monitor" Identifier "<default monitor>" DisplaySize 85 64 Option "DPI" "60 x 60" EndSection
I got the parameters from
Reboot. No effect.
I'm out of ideas (so does my favorite search engines). Any hints would be greatly appreciated!