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[Solved] Waveshare32b V4 LCD black screen on startx

Posted: Fri Mar 11, 2016 9:39 pm
by Sandbird
I dont understand why i am having such a hard time using my lcd with an old pi1 running the latest noobs, raspbian.....
I've done everything mentioned here: https://github.com/swkim01/waveshare-dtoverlays on how to get this working.
Adding

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fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo
to my cmdline.txt actually allows me to see the boot up text scrolling on the screen, but right when the pi is about to get into startx the screen on the LCD goes black.....no arrow no nothing.

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root@raspberrypi:~# dmesg | grep spi
[   13.112103] spi spi0.1: setting up native-CS1 as GPIO 7
[   13.112382] spi spi0.0: setting up native-CS0 as GPIO 8
[   13.168308] ads7846 spi0.1: touchscreen, irq 411
[   13.169415] input: ADS7846 Touchscreen as /devices/platform/soc/20204000.spi/spi_master/spi0/spi0.1/input/input3
[   13.596167] graphics fb1: fb_ili9340 frame buffer, 320x240, 150 KiB video memory, 4 KiB DMA buffer memory, fps=25, spi0.0 at 16 MHz
I also enabled spi via raspi-config.
What am i doing wrong here?
Thanks

Re: Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 12:51 am
by DirkS
You need to configure X to use the correct framebuffer.

Move /usr/share/X11/xorg.conf.d/99-fbturbo.conf out of the way:

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sudo mv /usr/share/X11/xorg.conf.d/99-fbturbo.conf \ ~/
Create new configuration file

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sudo nano /etc/X11/xorg.conf.d/99-fbdev.conf
with thr content

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Section "Device"
  Identifier "myfb"
  Driver "fbdev"
  Option "fbdev" "/dev/fb1"
EndSection
For the touch panel create the file /etc/X11/xorg.conf.d/99-calibration.conf

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sudo nano /etc/X11/xorg.conf.d/99-calibration.conf
containing

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Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ADS7846 Touchscreen"
        Option  "Calibration"   "219 3835 3984 219"
        Option  "SwapAxes"      "1"
EndSection

Re: Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 10:17 am
by Sandbird
DirkS wrote:You need to configure X to use the correct framebuffer.
oh crap, i thought this was not necessary anymore (using the new method since i dont have to patch the kernel anymore).
If i am not mistaken i remember leaving 99-fbturbo.conf as it is just change fb0 to fb1 ? Or i should just move it out of the way.
I guess if i ever want to hook up my display again, i have to reverse all the above right?

One final question. I've never figured out how to change resolution to the screen, to make the IDX 'fit' nicely in the display. Is that even an option ? Or because the screen is 320 x 240...thats the best it can do ?

Thanks DirkS for taking the time to answer this.

Re: Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 10:37 am
by DirkS
Sandbird wrote:If i am not mistaken i remember leaving 99-fbturbo.conf as it is just change fb0 to fb1 ? Or i should just move it out of the way.
The 'driver' entry in the conf file needs to be changed too. Moving it out of the way is easier to use (especially in scripts)
I guess if i ever want to hook up my display again, i have to reverse all the above right?
You don't need to undo all the changes. If you don't care about the console then you could probably get away with just swapping the 99-xxx.conf files.
One final question. I've never figured out how to change resolution to the screen, to make the IDX 'fit' nicely in the display. Is that even an option ? Or because the screen is 320 x 240...thats the best it can do ?
IIRC someone mentioned here on the forum that you could try to change the framebuffer size and it would then rescale, but I have never looked into it (I don't use X on my small screens)

Re: Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 10:47 am
by Sandbird
Awesome, thanks for the info :)

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 11:08 am
by Sandbird
sudo FRAMEBUFFER=/dev/fb1 startx -- -dpi 60

is the key to change resolution :)

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 2:18 pm
by DirkS
Sandbird wrote:sudo FRAMEBUFFER=/dev/fb1 startx -- -dpi 60

is the key to change resolution :)
That will cause problems at some point.
Running startx as root is not a good idea and should not be necessary.

Maybe you're running out of disk space...

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sat Mar 12, 2016 2:21 pm
by Sandbird
DirkS wrote:
Sandbird wrote:sudo FRAMEBUFFER=/dev/fb1 startx -- -dpi 60

is the key to change resolution :)
That will cause problems at some point.
Running startx as root is not a good idea and should not be necessary.

Maybe you're running out of disk space...
Adafruit had a trick where you add this at your .profile file, but that didnt work for me...so i have to manually execute startx like this.
My df -h:

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root@raspberrypi:~# df -h
df: β/run/user/0/gvfsβ: Transport endpoint is not connected
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       3.9G  3.4G  278M  93% /
devtmpfs        214M     0  214M   0% /dev
tmpfs           218M     0  218M   0% /dev/shm
tmpfs           218M  4.7M  213M   3% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           218M     0  218M   0% /sys/fs/cgroup
/dev/mmcblk0p6   63M   20M   44M  31% /boot
tmpfs            44M     0   44M   0% /run/user/1000
tmpfs            44M     0   44M   0% /run/user/0
/dev/mmcblk0p9  2.0G  885M 1017M  47% /media/pi/root-rbp1
/dev/mmcblk0p8   79M   20M   59M  26% /media/pi/boot-rbp1
/dev/mmcblk0p5   30M  669K   28M   3% /media/pi/SETTINGS
tmpfs            44M     0   44M   0% /run/user/109
These last 3 lines are from my osmc partition:

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/dev/mmcblk0p9  2.0G  885M 1017M  47% /media/pi/root-rbp1
/dev/mmcblk0p8   79M   20M   59M  26% /media/pi/boot-rbp1
/dev/mmcblk0p5   30M  669K   28M   3% /media/pi/SETTINGS
I'll remove some crap that raspbian has, like games etc.
Edit: Removed wolfram, minecraft, scratch, sonic and then autoremove and freed at least 800mb :)

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sun Mar 13, 2016 8:23 am
by DougieLawson

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/dev/root       3.9G  3.4G  278M  93% /
How big is your SDCard? Is it really a 4GB card? Or is it an 8GB card that hasn't had the filesystem expanded?

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sun Mar 13, 2016 10:27 am
by Sandbird
DougieLawson wrote:

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/dev/root       3.9G  3.4G  278M  93% /
How big is your SDCard? Is it really a 4GB card? Or is it an 8GB card that hasn't had the filesystem expanded?
Its an 8GB sd running oscm and raspbian. But since yesterday removed some unnecessary programs to make some space.

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Filesystem      Size  Used Avail Use% Mounted on
/dev/root       3.9G  2.4G  1.3G  65% /
devtmpfs        214M     0  214M   0% /dev
tmpfs           218M     0  218M   0% /dev/shm
tmpfs           218M  4.6M  213M   3% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           218M     0  218M   0% /sys/fs/cgroup
/dev/mmcblk0p6   63M   20M   44M  31% /boot
tmpfs            44M     0   44M   0% /run/user/1000
/dev/mmcblk0p9  2.0G  916M  986M  49% /media/pi/root-rbp1
/dev/mmcblk0p8   79M   20M   59M  26% /media/pi/boot-rbp1
/dev/mmcblk0p5   30M  669K   28M   3% /media/pi/SETTINGS
tmpfs            44M     0   44M   0% /run/user/0

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sun Mar 13, 2016 1:25 pm
by DougieLawson
Sandbird wrote: Its an 8GB sd running oscm and raspbian. But since yesterday removed some unnecessary programs to make some space.
OK, so you're suffering from the perils of NOOBS. You've lost nearly 1GB just to have that installed then you're restricting the two OSes.

It's always better to have one OS per SDcard by ditching NOOBS.

Re: [Solved] Waveshare32b V4 LCD black screen on startx

Posted: Sun Mar 13, 2016 1:32 pm
by Sandbird
DougieLawson wrote:
Sandbird wrote: Its an 8GB sd running oscm and raspbian. But since yesterday removed some unnecessary programs to make some space.
OK, so you're suffering from the perils of NOOBS. You've lost nearly 1GB just to have that installed then you're restricting the two OSes.
It's always better to have one OS per SDcard by ditching NOOBS.
Yes, unfortunately...But its ok...1.3something GB for osmc is fine..its plenty of space.