RockPi 4C+ DSI displays not working (Solved!)

#1

I cannot for the life of me get a DSI display to work on the 4C+.

I have 2 different 5 inch TFT displays for it. I have tried both and neither work.
I have 2 of the 0.3mm to 0.5mm FPC cables from ALLNET China, and neither of them change anything.
I have tried both Android 11 and the Ubuntu server image, and I get the same results for both.

On my Raspberry Pi display, I get a blank white screen.
On my DFRobot display, the screen flashes white, then I get a blank black screen.

Has anyone gotten a rockpi 4c+'s DSI port to work?

This is my first time installing DSI cables. I put them in the way that makes sense. 0.3mm pins facing away from the board, so that the 0.5mm pins will slot into the displays. They are as far into the slots as they can go. Both ends are locked using the black-locking-thingy.

Gonna try the debian image to see if I get anything different.

#2

Ok, so debian did not change anything, but upon further reading:

https://wiki.radxa.com/Rockpi4/hardware/display

I have found that the display needs to be enabled. I have also noticed that on the 4C+ the only listed displays in /boot/hw_intfc.conf are the WaveShare 3.5 and Raxda Display 10HD. Not happy about this. Going to investigate deeper into device tree overlays on the device to see if a standard rapsberry pi 7 in display can be supported on the 4C+

#3

raspberrypi-7-inch-lcd.dtbo is missing on debian on the 4c+. I get the feeling that raspberry pi dsi displays aren’t supported on it. This probably has to do with the form factor or pin count of the FPC connector.

#4

Hi, @smartguy1196

Please use the latest ROCK 4C+ image.

https://github.com/radxa/debos-radxa/releases/download/20221108-0141/rock-4c-plus-debian-bullseye-xfce4-arm64-20221108-0405-gpt.img.xz

The dtbo related to Radxa Display 10HD on ROCK 4C+ is

# enable radxa display 10hd on ROCK 4C+
intfc:dtoverlay=rock-4c-plus-radxa-display-10hd

The dtbo related to RaspberryPi touchscreen on ROCK 4C+ is

# enable raspbeerypi touchscreen on ROCK 4C+
intfc:dtoverlay=rock-4c-plus-raspberrypi-7inch-touchscreen

And you need the following fpc when using raspberrypi touchscreen.

radxa-mipi-fpc
radxa-mipi-fpc.jpeg2932Ă—1280 518 KB

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#5

@Stephen Thanks for the info here. I have checked a bit online, where can I find a place to source that MIPI DSI 0.3 to 1mm cable? Would there be any North American distributors? Is there a known part number for it?

Thanks

#6

I believe the only distributor is ALLNETCHINA. FPC connectors are use-case specific, and even more so on adapter cables. Basically, this part is custom.

#7

@Stephen Hi, can I use this release to directly boot from SSD? Is there a CLI version without Desktop Server?

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#8

The 39pinout is carefully defined and we think it’s the best option for 4-lanes dsi + touch and even with a gsensor on the display panel. It’s used across new radxa sbc including:

  • 4C+
  • 5B
  • Zero 2
  • 5A

The 10 inch or 8 inch display comes with the right FPC cable. FPC adapter cable for the RPi display will be available across different distributors.

#9

You could always try to remove the Desktop environment from debian:

#10

Trying the new image now, I’ll let y’all know how it goes. I’ll also try to remove the GUI for funsies to see how well that works.

@Harakiri I’m assuming this is to setup some kind of terminal like PC using DSI display?

#11

First try: boot stuck on “mmc2:mmc host rescan start!” retrying.

Opened Github issue: https://github.com/radxa/debos-radxa/issues/41

Resolved - power related.

Originally used a 5v @ 1a adapter. As soon as wifi kicked on, the machine shut itself down instantly

Switched to 5/9/12v @3a adapter. Machine would not start

Switched to 5v @ 2a, machine works.

Setting up display settings now

#12

Ok, I just now realized that I got the original screen descriptions wrong for which ones I’m using. Doesn’t matter though, because both of the ones I have now work. Using them as “rock-4c-plus-raspberrypi-7inch-touchscreen”

Raspberry Pi 5" TFT Module MIPI DSI - works!
DFROBOT 5" TFT-Display with Touchscreen(V3.0) - works! - Also, I recommend this touchscreen, if you are looking for a 5inch. It comes with a built-in brightness dial

DFROBOT 5 inch screen:

20221119_204320
20221119_204320.jpg4000Ă—3000 3.25 MB

RPI 5 inch screen:
20221119_204800_1

Video of touch response (both touch screens are responsive to touch!):
https://drive.google.com/file/d/155en7p_PIgCOqRocjx_LzwGb_ofJ96uJ/view?usp=sharing

Wiring:

20221119_204530_1
20221119_204530_1.gif368Ă—654 2.49 MB

Rock Pi 4 SE DSI display not working
#13

@Stephen works. see above.
@Harakiri now that it works, I’ll test to see if I can remove the GUI. I will be making the changes over serial console connection, but in theory you should be able to do this with the screen and a keyboard connected.

#14

@hakiri the method in the stackexchange post does not seem to work :confused:
sorry…

#15

Yeah, I’m using the RockPI 4C+ for a home automation server which hosts a dashboard for my KNX based infrastructure and will also LOG events to a local database hence why i switched (or want to) switch from a PI to a RockPI because its small enough to fit into my case with an SSD - the case will be put directly in my wirering cabinet

I just got this link shared https://jamesachambers.com/radxa-rock-pi-4c-plus-ssd-boot-guide/ where somebody installed the official debian image on the PI4C+ so I will try this as well.

#16

Hi,

Try ubuntu server image, https://github.com/radxa/debos-radxa/releases/download/20221108-0141/rock-4c-plus-ubuntu-focal-server-arm64-20221108-0253-gpt.img.xz