7'' LCD not working on PandaBoard with Linaro 2.3.5

Discuss TI Beagleboard, Pandaboard, their related extensions and accessories
fanchb
Posts: 9
Joined: Tue Dec 06, 2011 11:04 am

7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by fanchb » Mon Dec 12, 2011 8:12 am

Hello,

We have been testing the 7'' TFT LCD with the Linaro 2.3.5 version
(internal version of Linaro is 11.09) and we still cannot make the display
work properly. We have tried with both 0 and 33 ohms resistors and we use
Revision A3 of the Panda Board.

Please find attached the log of messages
at boot time. I hope it can help you diagnose why we still have that issue.
There is a Display error message appearing at the end.

Francois
Attachments
cutecom.jpg
cutecom.jpg (238.88 KiB) Viewed 10006 times

esky-sh
Posts: 1435
Joined: Sat Dec 20, 2008 4:21 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by esky-sh » Mon Dec 12, 2011 8:28 pm

The software image on FTP works with Pandaboard Rev A2 well. I had a quick check with pandaboard.org and found those comments:
** Rev A3 is the same as A2 except it has: OMAP4430 ES2.2 silicon version
http://www.pandaboard.org/content/resources/references

Could you tell us more details for the issues you were facing:
1. What issues you met as 'not work' in your statement?
Some technical words make sense for investigation should like "serial console freeze", "system halt", "LCD screen stay white", "LCD screen stay black", etc.

2. When you upload log, a complete log message start from reboot will be more helpful for our analysis.
You can either type "dmesg -n8 " to list these messages.

3. Have you had a test with linaro official 11.09 release with a DVI monitor?
This will be very helpful for problem isolation.
http://releases.linaro.org/platform/lin ... leb-panda/

4. How many resistors you populated on your Pandaboard?
You *******SHOULD NOT**** to solder all resistors up on back of board.
viewtopic.php?f=19&t=470

esky-sh
Posts: 1435
Joined: Sat Dec 20, 2008 4:21 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by esky-sh » Wed Dec 14, 2011 10:30 pm

A sample log file attached as reference for troubleshooting of beada frame related software issues.
Pandaboard Rev A2 + Android 2.3.5 from linaro release + Beada Frame
Attachments
pandaboard_Rev_A2_Android_2_3_5_Boot.zip
(10.25 KiB) Downloaded 457 times

fanchb
Posts: 9
Joined: Tue Dec 06, 2011 11:04 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by fanchb » Thu Dec 15, 2011 1:05 pm

Hello,

Thank you for your 2 replies. First of all, we have both PandaBoards Rev A2 and A3 so we have done the last tests with Rev A2 to be compliant with your setup. Here are my answers about your 4 questions, then the steps we have followed and pending questions:

1. When I mention that is does not work, I mean that whatever we try, we just see the backlight of the LCD flashing once at power up and later the screen stays black

2. Here is our log which is very similar to yours:

3. With linaro official 11.09 release with a DVI monitor, the DVI monitor stays black since all resistors ((R40-R43, R45, R46, R48-R53, R64-R73, and R80-R85, according to PandaBoard data sheet) on the top side have been removed. This behavior seems OK since we want the extension LCD to be working, not the DVI.

4. How many resistors you populated on your Pandaboard?
The only resistor which is not populated is R175.

5. Steps followed:
We have added J1 and J4 connectors and he put the 33 ohm on R176-203 locations, but the LCD screen was black. So we changed the resistors to 0 ohm instead, and it did not work either. After investigation we found in the panda board datasheet that we had forgotten to remove the B and C resistors section on the panda board (R40-R43, R45, R46, R48-R53, R64-R73, and R80-R85). We removed them and it did not work either.

6. Pending questions
We also measured the power on J1 and J2 connectors. We have 5V on pin 1 and 2 of J1, 1.8v on pin 2 of J4 but nothing on pin 1 of J4! VDD_Vaux2 is 0V… it is supposed to be between 1.2V to 2.8V. Do we need to set it by software ? Also we have noticed that R3 exp-pwen is not populated by a resistor. Do we have to put a resistor there ? Some pictures of the panda board we found on the web have such a resistor when there is an extension display.

Thank you!
Attachments
ZOC1112-PandaBoardWith7inchesLCD.zip
(10.2 KiB) Downloaded 427 times

esky-sh
Posts: 1435
Joined: Sat Dec 20, 2008 4:21 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by esky-sh » Thu Dec 15, 2011 7:09 pm

thanks for the detailed info. we can start troubleshooting now. :)
1. the log you attached tells us that you are using a uImage from linaro 11.09 'official' release.
Why don't you use the uImage file on FTP that customerized for our beada frame?
difference.jpg
difference.jpg (360.16 KiB) Viewed 9846 times
2. you do not need to remove resistors bank B and C on front of pandaboard, when you try to test LCD i/f on back of board.
OMAP4430 DSS signals can be routed to 2 destinations(dvi and lcd) simultaneously, actually this is what we were doing in our lab. :)

fanchb
Posts: 9
Joined: Tue Dec 06, 2011 11:04 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by fanchb » Tue Dec 20, 2011 1:07 pm

Hi,

We have continued the debugging of the LCD with the image and boot provided on your FTP site. We have noticed a change, the screen becomes blank after a few seconds. However, it never shows up Android booting. I have attached the new log, and noticed a diffrence with your log.

You have line: [ 1.076629] pwm_beada 2-0053: Rev.0 Backlight

In our case we have:
[ 1.202087] pwm_beada 2-0053: failed to write
[ 1.203887] pwm_beada: probe of 2-0053 failed with error -5

Could it be the reason of our problem ? Can we send you back the LCD unit for further investigation ?

Thank you!
Attachments
LOG_with_LCD7_only.zip
(10.45 KiB) Downloaded 497 times

esky-sh
Posts: 1435
Joined: Sat Dec 20, 2008 4:21 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by esky-sh » Tue Dec 20, 2011 7:50 pm

Great catch! Thanks for your continous efforts on troubleshooting and leading us arrive the solution.
There is an known issue in our early pandaboard customers before December, 'I2C write error, caused by NBD01 3.3v setup too later'

Here are our suggestions:
1. To confirm with this issue, please type reboot command on your serial console when android boot up. Then you will find I2C wirte error disappear and LCD backlight start to work.
2. For a final solution, you may need to change C3 on NBD01 board from 22uF to 10uF, this will allow a shorter power setup time for I2C work between pandaboard and NBD01.
3. If you can not find appropriate capcitor on your hand, just leave C3 blank.

Sorry for inconvenice caused by this issue.

fanchb
Posts: 9
Joined: Tue Dec 06, 2011 11:04 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by fanchb » Wed Dec 21, 2011 6:42 am

I have checked the log I sent you and I don't find 'I2C write error, caused by NBD01 3.3v setup too later' in it. I guess you assume we may have that error but it does not appear in the log.

As you suggested, we have replaced C3 with a 10uF capacitor. I also tried to type "reboot" at prompt but it does not seem to be accepted. Do you mean the simple "boot" command instead ? I tried that and I have attached a new log which does not seem to be different from the previous one. The LCD screen stays blank.

Please let me know how I can execute the "reboot" command.

Thank you!
Attachments
Log - 20111221.zip
(9.84 KiB) Downloaded 378 times

esky-sh
Posts: 1435
Joined: Sat Dec 20, 2008 4:21 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by esky-sh » Wed Dec 21, 2011 7:17 pm

fanchb wrote:I have checked the log I sent you and I don't find 'I2C write error, caused by NBD01 3.3v setup too later' in it. I guess you assume we may have that error but it does not appear in the log.
i2c_write_failure.png
i2c_write_failure.png (179 KiB) Viewed 9682 times
fanchb wrote: Please let me know how I can execute the "reboot" command.

Thank you!
reboot.png
reboot.png (69.58 KiB) Viewed 9686 times

fanchb
Posts: 9
Joined: Tue Dec 06, 2011 11:04 am

Re: 7'' LCD not working on PandaBoard with Linaro 2.3.5

Post by fanchb » Thu Dec 22, 2011 6:45 am

I have been able to reboot the panda board but it does not help, the screen stays blank. What do you suggest ? Can we send it back to you ?

In the meantime, we will purchase another one, we need it to work on the panda board. If it works OK, we will probably buy a few extra ones.

Thank you!

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