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Apologies even before I start!!! :-) I am new to this and only in because I said to someone it would be nice to have a 4k LCD on my Wanhao D7 Plus printer. 6 months later and having completely gutted it of all electrics bar motor, on/off switch and end switch, all I have working is the Z-Axis and UV!
So I have a 5.5" 4k LCD, and a config. The LCD comes as a kit; LCD, 4k MIPI board, 60 pin ribbon, 4k HDMI board. When the board is plugged in it blinks a blue LED. When a signal is passed it SHOULD light up constant GREEN. In the printer mine just blinks the BLUE LED. If I plug a monitor into the Pi4B it works - of sorts. My monitor doesn't have the same resolution, but the images are there none-the-less, so I know the Pi is working, and the cables out.
If I plug the HDMI board into a laptop, the board LED changes to constant GREEN. So that is telling me that the config is wrong in some way. Note I now know the LCD is faulty, (probably sent a duff one), however, as the HDMI does not light up correctly, I also know my config is wrong, or worse, the Pi4B doesn't do 4k. Can someone who knows the code and knows about these please check my config for errors and also give me some advise. In the mean time I am sorting another LCD.
Here is the LCD I bought. Not quite sure how good the seller is as they have disappered after I ran all the tests they asked to prove it wasn't working! https://www.aliexpress.com/item/4000152 … 4c4dJCxjo4
# 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=2
hdmi_mode=87
# 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 the lirc-rpi module
#dtoverlay=lirc-rpi
# Additional overlays and parameters are documented /boot/overlays/README
# Enable audio (loads snd_bcm2835)
dtparam=audio=off
[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
hdmi_enable_4kp60=1
hdmi_pixel_encoding=2
hdmi_timings=2160 0 105 32 100 3840 0 12 2 10 0 0 0 24 0 222290000 0
hdmi_pixel_freq_limit=400000000
hvs_priority=0x32ff
max_framebuffer_width=2160
max_framebuffer_height=3840
framebuffer_depth=24
framebuffer_ignore_alpha=1
disable_camera_led=1
start_x=1
enable_uart=1
#gpu_mem=128
gpu_mem=192
#############################
#From LCD Manufacturer
gpu_freq=300
force_trubo=1
core_freq=400
# Portrait or Landscape Setting
#Portrait-1 (Flexible cable is bottom side.)
#? This line contradicts our input - display_rotate=0x10000
display_rotate=0
framebuffer_width=2160
framebuffer_height=3840
# Landscape-1 (Flexible cable is right side.)
#display_rotate=1
#framebuffer_width=3840
#framebuffer_height=2160
# Portrait-2 (Flexible cable is upper side.)
#display_rotate=2
#framebuffer_width=2160
#framebuffer_height=3840
# Landscape-2 (Flexible cable is left side.)
#display_rotate=3
#framebuffer_width=3840
#framebuffer_height=2160
# For more options and information see
# http://www.raspberrypi.org/documentation/configuration/config-txt.md
# Some settings may impact device functionality. See link above for detailsLast edited by Jonners59 (2020-10-30 11:09:38)
Jonners59
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ANy help, please?????
Jonners59
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Change start_x value from 1 to 0
Also checkout guide on those HDMI timing and other specs, the most probably you could find correct value for pi4.
https://www.raspberrypi.org/forums/view … p?t=228128
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Change start_x value from 1 to 0
Also checkout guide on those HDMI timing and other specs, the most probably you could find correct value for pi4.
https://www.raspberrypi.org/forums/view … p?t=228128
Thank you.
Made the start value change. Also, I have looked at that link. Need to get to the bottom. I have added the missing entries and changed the timings.
Question: My framebuffer_width and frame buffer_height are the other way around. Does that affect the timings? Will I need to change the buffer comments and also rotation to accommodate that these timings and the example are the other way around???? Maybe a silly question to you, but me this is rocket science and you are all geniuses.
start_x value=0
hdmi_ignore_edid=0xa5000080
core_freq=500
sdram_freq=600
sdram_schmoo=0x02000020
hdmi_timings=3840 1 176 88 296 2160 1 8 10 72 0 0 0 25 0 247500000 3Jonners59
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Usually framebuffer will get ignored if you are using BCM.
Not sure about timing.
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Usually framebuffer will get ignored if you are using BCM.
Not sure about timing.
Thanks, but what is BCM, and does my config say I am using it?????
I am concerned that the scale and size of the projection are right for my LCD and print area. I do not know how to adjust them and how to get them right? I think once I have that then I can move on. I looked at the various screen calibration buttons but whilst they make pretty pictures there is nothing to say what it should look like across the print area and how to adjust it, esp the boarders
Jonners59
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As above, what is BMC?
Jonners59
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On Pi when framebuffer is not enabled, BCM will be utilized.
Personally I use boundary calibration then if some part is not visible or instead of border being render inside of the display, I adjust overscan options on config.txt
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On Pi when framebuffer is not enabled, BCM will be utilized.
Personally I use boundary calibration then if some part is not visible or instead of border being render inside of the display, I adjust overscan options on config.txt
Thank you...
Jonners59
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WORKING!
The 4k 2160*3840 LS055D1SX05(G) 5.5" LCD is now working. It MAY not work for all 4K LCDs. Check the size and LS#
Solution:
Two files to change in the BOOT directory.
1. Add this
video=HDMI-A-1:2160x3840MR-16@60eDto the end of the file cmdline.txt
2. config.txt =
#Jonathan's code for a 4k 2160*3840 LS055D1SX05(G) 5.5" LCD
disable_splash=1
boot_delay=0
dtoverlay=pi3-disable-bt
hdmi_ignore_cec_init=1
[pi4]
max_framebuffers=2
framebuffer_priority=2
[all]
hvs_priority=0x32ff
force_turbo=1
gpu_mem=256
enable_uart=1
start_x=0
disable_overscan=1
overscan_top=65
overscan_bottom=10
hdmi_ignore_edid=0xa5000080
hdmi_force_hotplug=1
hdmi_drive=1
hdmi_enable_4kp60=1
hdmi_group=2
hdmi_mode=87
hdmi_pixel_encoding=2
hdmi_pixel_freq_limit=700000000
#hdmi_timings=2160 0 106 32 100 3840 0 12 2 10 0 0 0 24 0 222380928 0
hdmi_timings=2160 0 106 32 100 3840 0 12 2 10 0 0 0 60 0 277976160 3
framebuffer_width=2160
framebuffer_height=3840
framebuffer_depth=16
framebuffer_ignore_alpha=1
max_framebuffer_width=2160
max_framebuffer_height=3840Hope this saves someone else a lot of time and money - I started in May and have spent nearly £1,000 in LCDs and hardware to get to this point!
Jonners59
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@Jonners59 god bless your soul !!!
I'm very new to nanodlp and to pi. and i bought all the things i needed including 4k LCD. i tested last night for the first time, and only the LCD didn't work, in monitor it did work, and now you got the answer.
i haven't made the fix yet, but i hope this will work for me.
the only change is i have pi3b does this code:
[pi4]
max_framebuffers=2
framebuffer_priority=2
need to be changed ?
or maybe all the config.txt ?
and i have a different model DBT055QUM
Last edited by shmulik (2021-01-11 21:46:21)
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Well, I do find these types of forum extremely frustrating, as it takes a life time and great distress and cost to get the answer, so was keen to share.
So I can only comment, as I am NOT a SW capable person and almost all I have learned and put together has been through extreme pain, as per my comment started in May and so far spent c£1,000 on mostly screens and associated parts.
Key is this is a 4k LCD at 5.5" and model number LS055D1SX05(G) Check that.
Also this is a Pi4B. I went for the 4, not 2 or 3 as given it was the latest I felt it would be a better investment with a longer life. That remains to be seen.
So from what you say below. Pi3, can not answer, but believe it will not hurt.
DBT055QUM I assume the screen #. That I can not answer. The hdmi_timings= will almost certainly not work. That is unique to the LCD screen model. You need to speak to the manufacturer to get that, and many (Chinese) do not have them or refuse to share. There is a pattern to the numbers and a couple of formula, though I have to say the two formula I got didn't make sense when using to check each other. Not helpful.
Jonners59
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how did you manage to make it work if you didn't understand the formula?
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how did you manage to make it work if you didn't understand the formula?
Trial and error, loads of reading, and loads of time.
The two formulas I got from the nanoDLP docs, but they contradict themselves. One works out the <frame_rate> (frequency) and the other the <pixel_freq>, but they contradict each other as they use the same elents of hdmi_timings=<h_active_pixels> <h_sync_polarity> <h_front_porch> <h_sync_pulse> <h_back_porch> <v_active_lines> <v_sync_polarity> <v_front_porch> <v_sync_pulse> <v_back_porch> <v_sync_offset_a> <v_sync_offset_b> <pixel_rep> <frame_rate> <interlaced> <pixel_freq> <aspect_ratio>
SO this: 2160 0 106 32 100 3840 0 12 2 10 0 0 0 24 0 222290000 0
2160 0 106 32 100
3840 0 12 2 10
24
222290000 / ((2160+105+32+100) * (3840+12+2+10)) = 24Hz / fps
but this
<pixel_freq> = clock frequency (width*height*framerate)
199065600=2160*3840*24
SO we have two <pixel_freq> 199065600 and 222290000
Jonners59
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