'No Signal' on LCD screen using Beagle Bone Black and HDMI


#1

I am using beagle bone black and 7 inch LCD screen for display.Image i created on SD card is debian9.I enabled video and cape_universal in /boot/uEnv.txt

enable_uboot_overlays=1
enable_uboot_overlays_emmc=1
enable_uboot_overlays_video=1
enable_uboot_cape_universal=1

Even though i get ‘No Signal’ on LCD screen.I have attached screen shot

After boot process i see version.sh

will someone please help me to solve this issue?
Is there something setting required on new beagle bone black to enable HDMI?


#2

@Neha9 what LCD panel is that?

Couple Problems, first your eeprom didn’t get properly written (BeagleBone Green doesn’t have HDMI) that is easy fixed via Grounding, TP4 (between ethernet and barrel plug) then run as root:

dd if=/opt/scripts/device/bone/bbb-eeprom.dump of=/sys/devices/platform/ocp/44e0b000.i2c/i2c-0/0-0050/eeprom

and rebooting…

Next looking at your output of version.sh the u-boot (2016.03) is too old to support overlays:

Just run:

debian@beaglebone:~$ cd /opt/scripts/tools/developers/
debian@beaglebone:/opt/scripts/tools/developers$ git pull
debian@beaglebone:/opt/scripts/tools/developers$ sudo ./update_bootloader.sh
debian@beaglebone:/opt/scripts/tools/developers$ sudo reboot

Regards,


#3

Thank you, Sir, for the reply,

It is 7 inch HDMI Display-C 1024*600 pixels

For the following answer,

first, your EEPROM didn’t get properly written (BeagleBone Green doesn’t have HDMI) that is easily fixed via Grounding, TP4 (between ethernet and barrel plug) then run as root:

dd if=/opt/scripts/device/bone/bbb-eeprom.dump of=/sys/devices/platform/ocp/44e0b000.i2c/i2c-0/0-0050/eeprom

But, as I mention I am using Beaglebone Black, is above answer same for BBB?


#4

@Neha9 correct, that command is for the BeagleBone Black. I was just commenting why hdmi didn’t work, as since it was detected as Green.

Regards


#5

Thank you Sir :slight_smile:

It worked for me :slight_smile:


#6

Sir,

I am trying to use CAN protocol in beagle bone black. I referred this website,

http://www.thomas-wedemeyer.de/beaglebone-canbus-python.html.

After doing all the steps, I tried to run the code but not able to get output and even able to understand what is wrong with it and why it is not working.

Please let me know if any other way is there for CAN protocol communication with beaglebone black.


#7

@Neha9 these can questions come up quite a bit on the beagleboard forum:

https://groups.google.com/forum/#!searchin/beagleboard/can|sort:date/beagleboard/fPk45dXWWVI/sA1oc01JDAAJ

In the default boot-up state, make sure you use “config-pin” to correctly mux the can port pins. Or using the u-boot overlay for can:

https://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_.2Fboot.2FuEnv.txt_configuration

and make sure to have something actually connected to the can port.

Regards,


#8

Thank You, Sir

It helped me to get CAN output :wink: