Trying to get Miuzei 4" LCD to work
I just purchased a Miuzei 4" LCD touchscreen for a RPi 4. After loading the image I got WiFi working and now just need to get the display up and running. I don't see anything listed in the drivers that matches the LCD model (MC21-4) that are included in the ModBro image. I tried leaving it at HDMI and also tried 5 or 6 of the included drivers that looked like they were for 4" 800x400 displays. None of them worked.
The manufacturer's webpage states this display works with the standard Raspian O/S. They also include 3 links for various drivers. The Raspian driver link is no good. But there's a working link for “Kali” and “Raspian Buster Lite”. But then it occurred to me that I have no idea how to load these drivers anyway. The Miuzei's site is of no help.
I'm a linux noob. I'm willing to try the 2 available drivers if someone can tell me how to install them.
Thought the link to the manufacturers page might be handy
The display you linked states that is supports HDMI, so if you don't need the touchscreen functionality i would just use it plain over HDMI.
Did you connect the small included HDMI to Micro HDMI bridge?
Also you stated that you tried leaving it at HDMI. Was this at your first try or did you install a driver prior to that?
Because ‘leaving it at HDMI’ in the configuration wizard does only skip the driver install. It will NOT reset to the HDMI configuration if you already installed a driver previously.
Yes, the HDMI bridge is installed. When the RPi first boots up I see the text scrolling by on the 4" screen.
I decided to start over again. I re-imaged the SD card and went through the setup process. I made sure to not install any driver but leave the setup for that step at the default HDMI.
After finishing the setup and applying the settings, it reboots and all I get is a blue screen with “no signal" displayed in the center.
I then removed the HDMI bridge and connected a regular HDMI monitor to the RPI. When I boot with that I get a working screen. The monitor says it's getting a 640x480 display. I wonder if that default resolution isn't supported by my 4" screen (800x480).
Is there a way to SSH in and change the resolution?
Yeah sure you can normally connect to it by SSH. username and password are both ‘modbros’
The image is just a normal ‘Raspbian Buster Lite’ that is pre-configured by us and running our service.
If you're connected you will have to modify the config.txt file which is located under /boot/config.txt
If you open it, there should currently be these values right at the bottom:
hdmi_group=2
hdmi_drive=1
hdmi_mode=4Change those to these ones:
(these are listed in the documentation of the chinese display you linked)
hdmi_group=2
hdmi_mode=87
display_rotate=3
hdmi_cvt 480 800 60 6 0 0 0Thanks! That got it working.
However, one more question. It's now in portrait mode. I need to rotate it 90 degrees for landscape mode. I thought that would be easy by changing the display_rotate line. But no matter what number I put in there the display orientation stays the same. I even tried reversing the “480 800” to “800 480” but that didn't work either.
Is there a way to fix this?
You could check out the official Raspberry Pi documentation here:
https://www.raspberrypi.org/documentation/configuration/display_rotation.md
Note that you have to restart the Pi after you made changes to the config.txt
Thanks.
I don't want to waste anymore of your time with this.
I've tried everything. It's just not compatible with your app.
No worries.
I just had a look at your display again.
They also link this page: http://www.lcdwiki.com/4inch_HDMI_Display-C
So you could try to install the ‘MPI4008-show’ driver from GoodTFT which is also already available on our image.
If the screen works with that one you would have to SSH onto the Pi again.
Navigate to /home/modbros/display-drivers/GoodTFT
Then execute the following: sudo ./rotate.sh 90
(' 90 ' represents the rotation angle and can be changed to 0 degrees, 90 degrees, 180 degrees, 270 degrees）