nanoDLP

flotec1

Member

Registered: 2020-07-15

Posts: 4

DuoBond 8.9 inch 4K Mono LCD 3840x2400

Maybe someone has already had success with a PI4 (Raspbian Lite) and a 4K LCD with NanoDLP, I have not yet found the correct settings in the \boot\config.txt.

The manufacturer says I should use this settings on the PI 1280*2400, under DLP mode, it is 3840*2400

/boot/config.txt

disable_overscan=1
hdmi_ignore_edid=0xa5000080
hdmi_group=2
hdmi_mode=87
hdmi_cvt 3840 2160 24
config_hdmi_boost=7
framebuffer_width=3840
framebuffer_height=2160
max_framebuffer_width=3840
max_framebuffer_height=2160
hdmi_pixel_freq_limit=400000000

yushuiqiang2008

Member

From: China

Registered: 2020-08-27

Posts: 2

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

The settings resolution is 1280*2400,because the x-dir resolution is RGB(three dot) , so three dot just for one resolution.

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FDM LCD DLP SLA Raspberry software

flotec1

Member

Registered: 2020-07-15

Posts: 4

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

It's monochrome LCD display not RGB

yushuiqiang2008

Member

From: China

Registered: 2020-08-27

Posts: 2

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

the lcd driver is a RGB driver, the screen is a mono lcd. So the RGB driver is for three dots mono lcd. 3840/1280=3

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FDM LCD DLP SLA Raspberry software

macdarren

Member

Registered: 2017-03-20

Posts: 411

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

I have been looking at this display too....does this mean that while it is a mono display with 4k resolution with the driver being RGB we would only be able to access 1280 resolution, thus 3 pixels turn on with any given pixel represented in the model thus significantly reducing effective resolution?

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,546

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

Darren,

For 4K monochrome instead of 4096 × 2160 pixels, we send 4096/3 x 2160. So instead of each pixel representing by RGB it only represented by single color.
I doubt it affect end resolution for printing as still you have 256 grayscale level for each pixel.

flotec1

Member

Registered: 2020-07-15

Posts: 4

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

Then this settings on the Raspberry 4 should work?

hdmi_force_hotplug=1
hdmi_timings:0=1280 0 70 32 46 2400 0 62 20 28 0 0 0 50 0 179210000 0
hdmi_group=2
hdmi_mode=87
max_framebuffer_width=2400
max_framebuffer_height=1280
hdmi_drive=2
disable_overscan=1
dtoverlay=pi3-miniuart-bt
hdmi_ignore_edid:0=0xa5000080

Nano DLP Display
Horizontal Resolution = 3840
Vertical Resolution = 2400
X/Y Resolution= 50 µm

The Dynamic Calibration don't look right? Grid squares to big...

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

#iforce_trubo=1
#gpu_freq=300
#core_freq=400

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=0

# 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.
hdmi_ignore_edid:0=0xa5000080
#hdmi_pixel_freq_limit=400000000
#display_rotate=0
max_framebuffer_width:0=2560
max_framebuffer_height:0=2560
#framebuffer_width:0=1280
#framebuffer_height:0=2400

#hdmi_edid_file=1
#hdmi_edid_filename:0=edid_hdmi0.dat
#hdmi_edid_filemane:1=edid_hdmi0.dat

# 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:0=2
hdmi_mode:0=87
hdmi_timings:0=1280 0 70 32 46 2400 0 62 20 28 0 0 0 50 0 179210000 0

# 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=10

# 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=4

[all]
#dtoverlay=vc4-fkms-v3d

xiami

Member

Registered: 2021-04-27

Posts: 1

Re: DuoBond 8.9 inch 4K Mono LCD 3840x2400

I've tried this config on my own machine and it works perfectly. so you can try it out,I hope it can help you.

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

[all]
hdmi_force_hotplug：1=1
hdmi_mode:0=87
hdmi_pixel_freq_limit:1=500000000
hdmi_timings:1=1280 0 35 14 35 2400 0 62 6 28 0 0 0 50 0 170000000 0
dtparam=i2c1=on
dtparam=i2c_arm=on
hdmi_drive=2
disable_overscan:1=1
max_framebuffer_width=1280
max_framebuffer_height=2400
hdmi_group:1=2
config_hdmi_boost:1=4
display_rotate:1=0x10000
framebuffer_width:1=1280
framebuffer_height:1=2400
# Uncomment some or all of these to enable the optional hardware
# interfaces
dtparam=i2c_arm=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
start_x=1
#dtoverlay=pi3-disable-wifi
#dtoverlay=pi3-disable-bt
enable_uart=1
core_freq=250
gpu_mem=192