Raspberry Pi 4 7" Raspi Display does not show app

Question

Hi Embedded Wizards,

Still Don't see the APP on the 7" Screen.

The latest update is I just received the 7" Raspi Display and connected it to the Raspberry Pi 4B module. Verified touch screen working and also installed the keyboard and mouse driver by " sudo apt install matchbox-keyboard". I copied the "EmbeddedWizard-RasPi-4B" built on to the Raspberry Pi 4 module and executed the Hello World app ./EmbeddedWizard-RasPi-4B. This is what I see but NO Hello World GUI APP display on the 7" screen.

Here are the printouts on the 7" screen:

pi@raspberrypi:~/RPI_4/LatestBuild $ ./EmbeddedWizard-RasPi-4B
Using drm device node '/dev/dri/card1'!
ignoring unconnected connector 32
ignoring unconnected connector 42
Display interface 'DSI_0' detected.

Available output modes:
  800 x  480 @ 60Hz (pixel clock:   25979kHz) (preferred mode)

Preferred display mode requested

Selected display mode:  800x480@60Hz (pixel clock: 25979kHz)

Initialize Display...                        [OK]
Initialize Touch Driver...                   [OK]
Initialize Memory Manager...                 [OK]
Initialize Graphics Engine...                [OK]
Initialize Invocation Queue...               [OK]
Create Embedded Wizard Root Object...        [OK]
Create Embedded Wizard Viewport...           [OK]
Starting Embedded Wizard main loop - press <p> to shutdown application...
---------------------------------------------
Embedded Wizard System Info
---------------------------------------------
Target system                                RasPi-4B (OpenGL ES 2.0/EGL/DRM)
Color format                                 RGBA8888
Build Environment version                    V12.00.01.00
Runtime Environment (RTE) version            V12.00
Graphics Engine (GFX) version                V12.00
MemoryPool address                           0x00091764
MemoryPool size                              33554432 bytes
Display interface                            DSI
Display size                                 800 x 480
Viewport size                                800 x 480
Viewport rotation                            0
EwScreenSize                                 800 x 480
Graphics accelerator                         OpenGL ES 2.0
Warp function support                        enabled
Vector graphics support                      enabled
Gradients support                            enabled
Blur support                                 enabled
Mask support                                 enabled
Tint support                                 enabled
Bidirectional text support                   enabled

I'm not sure what the ignoring connectors mean?:

ignoring unconnected connector 32
ignoring unconnected connector 42

pi@raspberrypi:~ $ cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 11 (bullseye)"
NAME="Raspbian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"

Originally my SD card was flashed for 32 bit and I had verified it as per your instructions, but when I checked it again, the aarch64 means it is a 64bit OS as shown below:

pi@raspberrypi:~ $ uname -m
aarch64

Tells me this is 64 bit OS, but I had flashed it as a 32 bit OS and verified it, unfortunately I did not document initial check for 32 bit OS.

I'm not sure why this OS change occurred, could the apt-get update apt-get upgrade commands may have changed it? Not sure. I'm going to re-start from scratch and flash another SD card with Bullseye 32 bit OS LITE, verify and document all the steps of checking the OS and see what happens. 

Raspberry Pi OS (Legacy) Lite
Release date: May 3rd 2023
System: 32-bit
Kernel version: 6.1
Debian version: 11 (bullseye)
Size: 364MB
Show SHA256 file integrity hash:

 Any other suggestions what what the unconnected connector 32, 42 mean would be appreciated?

Thanks,

ATI
 

Answer 1

Hi EW,

I flashed another 32GB SD card this time I made sure it was Legacy Bullseye 32bit OS LITE No Desktop: Followed the instructions at : Getting started with Raspberry Pi: Raspberry Pi 4 Model B (embedded-wizard.de), the Hello World and MasterDemo do work on the 7" Raspberry Pi touch display. One cavate is that I could not find the Buster Legacy on this Raspi Legacy link:  Operating system images – Raspberry Pi if I want to get the Apps working on Raspberry Pi 3.

 

To check the OS release type this:

 

pi@raspberrypi:~ $ cat /etc/os-release

PRETTY_NAME="Raspbian GNU/Linux 11 (bullseye)"
NAME="Raspbian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
 

To see kernal version of the OS is 32 or 64 bit use the command:

pi@raspberrypi:~ $  getconf LONG_BIT

32

 

cheers!

Comments

Thanks for sharing your observations.

Please note, that in case of RasPi 3, there is a separate Getting Started document, where we have put the link to Raspberry Pi OS Lite (Legacy) Buster. In case or RasPi 4 the Raspberry Pi OS Lite (32-bit) Bullseye is used.

Best regards,

Manfred.