BTT HDMI 7 screen

Frontends KlipperScreen
1

Hi all,

Apologies if this has been covered before. New HDMI 7" display from BTT - has anyone managed to get it to work with KlipperScreen on PI4? I have connected and modified boot.txt as per BTT pdf manual :

# uncomment to force a specific HDMI mode (this will force VGA)

hdmi_group=2
hdmi_mode=87
hdmi_cvt 1024 600 60 6 0 0 0

# uncomment to force a HDMI mode rather than DVI. This can make audio work in

# DMT (computer monitor) modes

hdmi_drive=1

I started to get console on boot but garbage instead of KlipperScreen.
Figured out that may be because I have set my PI up for “stock” PI screen before, and disabled dtoverlay:

[pi4]

# Enable DRM VC4 V3D driver on top of the dispmanx display stack

# dtoverlay=vc4-fkms-v3d # Disabled now

max_framebuffers=2

Now I have the KlipperScreen screen but it does not fit the display (like 2 time larger than it should. Any help is much appreciated.

TIA

2

Put an = before 1024. I don’t know that that’s the issue, but that brings it in line with the other settings. I got my 5” display working last night using similar settings.

3

Thanks, tried that (= was missing from BTT manual)… still does not work. It looks like this screen just does not want to go to 1024x600 mode. I have tried to use hdmi force mode and the screen just hangs with the rainbow.

4

This is my /boot/contig.txt that works with 7" Touchscreen and Pi3B I did not delete the uncommented lines to make it easier to compare…

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
dtoverlay=vc4-fkms-v3d
max_framebuffers=2

[all]
#dtoverlay=vc4-fkms-v3d
# enable raspicam
start_x=1
gpu_mem=128
overscan_scale=1
hdmi_force_edid_audio=1
hdmi_force_hotplug=1
dtparam=i2c_arm=on
dtparam=spi=on
enable_uart=1
display_rotate=0
max_usb_current=1
config_hdmi_boost=7
hdmi_group=2
hdmi_mode=87
hdmi_drive=2
hdmi_cvt 1024 600 60 6 0 0 0
5

Thanks, I since discovered that it works with Bullseye build of RasPI Linux but not with Buster based image.

6

I got the same problem myself: I moved klipper from a RasPi3B to a small PC (i3) i bought at *Bay for 65€ (I have to controle 2 printers and RasPi is too expensive today). But Klipperscreen is not working since I installed Ubuntu server 20 and I am a linux rookie and (so far) not able to get this 1024x600Px screen running but I will keep on trying… Meanwhile I use the “old” installation of KlipperScreen on the Pi with the PC, that works nicely. I made a housing for it: Raspberry 3b 7 inch Touchscreen cover by BergKaese - Thingiverse

Some days lator I got it running. Had some X-Issues that I solved and now I switched of my raspi and connect the 7" directely to the HDMI of my I3…

8

I was able to get mine working on buster with the following in the config.txt

#uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=2
hdmi_mode=87
hdmi_cvt=1024 600 60 6 0 0 0
#uncomment to force a HDMI mode rather than DVI. This can make audio work in DMT (computer monitor) modes
#hdmi_drive=1
#hdmi_force_edid_audio=1
#hdmi_force_hotplug=1
max_usb_current=1
config_hdmi_boost=10

[pi4]
#Enable DRM VC4 V3D driver on top of the dispmanx display stack
#dtoverlay=vc4-fkms-v3d
max_framebuffers=2