Falcon Christmas

Other Controllers and Hardware => General Hardware => Topic started by: rmp2917 on July 13, 2017, 06:24:49 AM

Title: P10 panel flickering outline
Post by: rmp2917 on July 13, 2017, 06:24:49 AM
I just setup a 4x4 P10 panel using a PI3 and a matrix hat from CFOL. The panels are also from CFOL.

There is a random flickering outline or random background pixels flickering (See video). Has anyone seen this issue or know what might be causing it?

https://vimeo.com/225397993 (https://vimeo.com/225397993)
https://vimeo.com/225398004 (https://vimeo.com/225398004)
Title: Re: P10 panel flickering outline
Post by: jnealand on July 13, 2017, 10:24:39 AM
First off be sure to close any open windows to the FPP.  It is a known problem that having an open interface window when running will cause flickering.
Title: Re: P10 panel flickering outline
Post by: TNF250 on July 13, 2017, 10:39:26 AM
I'm glad you brought this up. I have the same issue even when scrolling the information, no windows open on FPP. Panels came from Ray Wu. I thought it was a power issue because I'm running it from a battery pack. 
Title: Re: P10 panel flickering outline
Post by: rmp2917 on July 26, 2017, 05:52:19 PM
I've tried about everything I can think of and still have this flickering issue.

I'm pretty sure it is not a power issue. It happens even with only one panel connected and I'm using a 60 amp 5 volt mean well power supply. I also tried powering the Pi with a separate power supply, but get the exact same results. I've tried different cables and even a different matrix adapter.

It does it both in test mode from FPP and also while playing a sequence.

So, I don't know if it could be an issue with the panel itself or an issue with the Pi and FPP.

Any suggestions would be helpful.

Thanks, Rick
Title: Re: P10 panel flickering outline
Post by: Ebuechner on July 27, 2017, 05:09:32 AM
I've had a similar issue with panels I bought from Ray and Ron's pi adapter. What I found was it was the panels that were at the end of the data stream so I rearranged my panels so those panels are not in a prominent place on the display but in the corners.
Title: Re: P10 panel flickering outline
Post by: JonB256 on July 27, 2017, 09:26:56 AM
I see the flickering in the Videos. Since it is around the text, I'd suspect the Font being used rather than a panel problem.

The anti-aliasing used to make the font size changes may be causing it. Using Matrix tools, try drawing a few lines and see if you get anything around the lines.

If that text was moving, I don't think you would have that flickering concern.

I have a working 3x3 panel sitting next to me that I can use to duplicate your test if you describe it. (though I'm running an Octoscroller and dKulps newest BBB image)
Title: Re: P10 panel flickering outline
Post by: rmp2917 on July 28, 2017, 06:14:47 AM
I used Matrix tools to create the test text in the video. I made the video with still text because you could see the issue easier.

I also tried drawing lines, changing fonts, scrolling the text, etc. The ghosting/flickering is till there regardless what is being displayed unless the entire panel is lit. Anything with a black background or unlit pixels shows the ghosting. I even tried running a sequence with different fonts. I have ran a sequence in bridge mode from xlights and directly from FPP with a scheduled playlist and no browser windows open. All tests show the same flickering regardless of the brightness setting or any other settings.

I don't think it would be a panel problem unless all 16 panels have the same defect or design flaw.

I found some documentation that shows similar ghosting and describes how to fix it by changing the PWM nanoseconds for LSB using the following: --led-pwm-lsb-nanoseconds : PWM Nanoseconds for LSB (Default: 130). But, I don't know where to change this in the FPP code. Here is the link: https://github.com/hzeller/rpi-rgb-led-matrix (https://github.com/hzeller/rpi-rgb-led-matrix). There are some images and a description about half way down the page.

Right now the ghosting is bad enough that I'm not sure I will be able to use the matrix if I can't fix it.
Title: Re: P10 panel flickering outline
Post by: JonB256 on July 28, 2017, 07:07:31 AM
I tried duplicating your video and could not get that ghosting. My panels are about 3 years old so definitely a different batch and manufacturer.
Title: Re: P10 panel flickering outline
Post by: adster on August 02, 2017, 09:31:41 AM
Thank you for bringing this up! I, too, am having this same issue and I'm pulling my hair out. I don't think it's necessarily a panel issue because I've run test patterns on the panels and don't have the ghosting. Here's a video I made out of Xlights: https://youtu.be/mb5ZFugrdvI


The github link you referenced looks to be the exact problem (especially the "Ghosting with low --led-pwm-lsb-nanoseconds" photos). I wonder if we can summon CaptainMurdoch here to give his advice?
Title: Re: P10 panel flickering outline
Post by: dkulp on August 02, 2017, 10:21:00 AM
If any of you that are having this issue have a BBB and Octoscroller available, it might be worth while trying to duplicate it with the Octo to see if it's a panel issue or something with the timing of the PiHat code.
Title: Re: P10 panel flickering outline
Post by: jnealand on August 02, 2017, 02:00:47 PM
I have seen this problem on my P5 panels, but since you have to be up close to see it, I have not worried about.  I doubt anyone will see it from most show viewing areas.  I'm not saying it is not a problem, but that it is not something that will affect my show so therefore a non-issue for me.
Title: Re: P10 panel flickering outline
Post by: adster on August 02, 2017, 10:38:20 PM
If any of you that are having this issue have a BBB and Octoscroller available, it might be worth while trying to duplicate it with the Octo to see if it's a panel issue or something with the timing of the PiHat code.

That is a good idea! I don't have an Octoscroller available (I have one on order from DIY LED EXPRESS since January but not sure when that's coming...) but I do have a BBB available. I also have a ColorLight control board available, but as far as I know the ColorLight board isn't working with FPP yet. I have reached out to CFOL to see if they have an Octoscroller available!

I have seen this problem on my P5 panels, but since you have to be up close to see it, I have not worried about.  I doubt anyone will see it from most show viewing areas.  I'm not saying it is not a problem, but that it is not something that will affect my show so therefore a non-issue for me.


I noticed it wasn't noticeable past a few fee either, but my sign will be next to the street so I just wanted to see if maybe there is a way to fix the issue instead of live with it. Especially now that I see other people are having the same issue.
Title: Re: P10 panel flickering outline
Post by: JonB256 on August 03, 2017, 12:38:15 PM
I don't see any flicker with the Octoscroller. I am running Dkulps latest version.

Sent from my SM-G900V using Tapatalk

Title: Re: P10 panel flickering outline
Post by: rmp2917 on August 13, 2017, 12:31:41 AM
I was able to make some progress with this issue. Since FPP is using an older version of the RGB Matrix library, the settings shown in the documentation that I mentioned earlier are not available.

I was able to find a constant in the code that controls the PWM Nanoseconds for LSB. I manually changed it and rebuilt FPP using the following.

Code: [Select]
cd /opt/fpp/external/rpi-rgb-led-matrix/lib
sudo nano framebuffer.cc

modify the following line "static const long kBaseTimeNanos = 130;" and change 130 to 300
Save the file and exit

sudo make
cd /opt/fpp/src
sudo rm fppd
sudo make

I then restarted FPP and ran some tests.

The ghosting is now gone for the most part. It still seems to show a little when the text is first displayed but goes away completely after a second. So, I don't know if there is something else in the code that needs changed.

Would it be possible to update the library to the latest version and add this as a setting on the matrix page? I would be willing to do this myself even it was only on my local copy, but I am not that familiar with Linux or the FPP code. So, I would probably need a lot of help.
Title: Re: P10 panel flickering outline
Post by: mtosh on August 14, 2017, 05:48:10 AM
I had same issue and ended up switching to bbb. That still wasn't enough and had to run the beta of fpp on the bbb. Has something to do with refresh rate on the newer panels.


Sent from my iPhone using Tapatalk
Title: Re: P10 panel flickering outline
Post by: adster on August 22, 2017, 03:23:57 PM
Ok, so I got a BBB and Octoscroller and the ghosting issues are not a thing anymore! So there must be some code in the Raspberry Pi FPP that is making the panels ghost like that. I tried this on my P4 panels and some new P10 panels I got from DIY LED Express and it produces the same result, so I know it's not a panel issue.


Here's a video showing the difference between the two:
https://youtu.be/AjgYYqFHDSA
and part 2 showing with the updated dklup BBB image.
https://youtu.be/g-15zNuNIOk


However, now I'm getting some refresh issues with the top and bottom portion of the panel. Notice how the top half of the panel moves just slightly faster then the bottom half? This doesn't happen on the pi and is visible in part 2 of the above video.
Title: Re: P10 panel flickering outline
Post by: adster on August 22, 2017, 03:44:28 PM
I was able to make some progress with this issue. Since FPP is using an older version of the RGB Matrix library, the settings shown in the documentation that I mentioned earlier are not available.

I was able to find a constant in the code that controls the PWM Nanoseconds for LSB. I manually changed it and rebuilt FPP using the following.

Code: [Select]
cd /opt/fpp/external/rpi-rgb-led-matrix/lib
sudo nano framebuffer.cc

modify the following line "static const long kBaseTimeNanos = 130;" and change 130 to 300
Save the file and exit

sudo make
cd /opt/fpp/src
sudo rm fppd
sudo make

I then restarted FPP and ran some tests.

The ghosting is now gone for the most part. It still seems to show a little when the text is first displayed but goes away completely after a second. So, I don't know if there is something else in the code that needs changed.

Would it be possible to update the library to the latest version and add this as a setting on the matrix page? I would be willing to do this myself even it was only on my local copy, but I am not that familiar with Linux or the FPP code. So, I would probably need a lot of help.


After the
cd /opt/fpp/src
and
sudo rm fppd
I get an error: "rm: cannot remove `fppd': No such file or directory"
Should I remove fppd.*? I see fppd.c .h and .sh.
Title: Re: P10 panel flickering outline
Post by: rmp2917 on August 22, 2017, 10:32:09 PM
The FPP folder may be in a different directory depending an what version you are running. Make sure your FPP folder is under opt.
Title: Re: P10 panel flickering outline
Post by: Wichita on August 23, 2017, 10:43:02 AM
I am having the same issue with the random ghosting around text .  I am using a Pi3 with Rons  adapter and just received P10s.  I hope we can get this solved because it makes the matrix ugly.
Title: Re: P10 panel flickering outline
Post by: rmp2917 on August 23, 2017, 10:18:31 PM
After the
cd /opt/fpp/src
and
sudo rm fppd
I get an error: "rm: cannot remove `fppd': No such file or directory"
Should I remove fppd.*? I see fppd.c .h and .sh.

You don't want to delete any other files. I don't think the error is an issue just go ahead and run the sudo make at the end and see if it will build.

I am currently travelling and won't be back home until Sept. 1st. I will try to play with it some more and maybe create a new build if I get it working good.
Title: Re: P10 panel flickering outline
Post by: Wichita on September 04, 2017, 11:30:06 AM
Anyone figure out what the problem is.  Is there an update to the code? Any help would be greatly appreciated.
Title: Re: P10 panel flickering outline
Post by: dkuntz on September 05, 2017, 07:27:24 PM
I noticed this issue with "ghosting" around text on my p10 matrix tonight. I am powering my pi and matrix with the same power supply. I found the ghosting seemed to go away when I adjusted the voltage down to about 4.7 volts. I was surprised the pi seemed to continue to function at this voltage. I will be trying powering the pi with a separate supply when I get a chance. No idea why this made my ghosting go away.
Title: Re: P10 panel flickering outline
Post by: Wichita on September 06, 2017, 05:54:52 PM
I changed my pi to USB power instead of Ron's Adapter and the text is still very jagged.
Title: Re: P10 panel flickering outline
Post by: Wichita on September 06, 2017, 08:39:03 PM
Just tried a different Pi3 and a different Ron Matrix Adapter and still no luck. :-\. Anyone have any suggestions? I'll try anything. 
Title: Re: P10 panel flickering outline
Post by: rmp2917 on September 09, 2017, 11:53:37 AM
I have finally had some time to experiment with this some more and have made some progress.

The setting that seems to have the most effect is GPIO-slowdown. Changing it from 1 to 2 seems to completely get rid of the flickering pixels, but there is still some very faint ghosting especially on green and white. Changing the pwm_lsb_nanoseconds parameter from 130 to 300 completely gets rid of the ghosting but will decrease the refresh rate.

I recommend changing the GPIO-slowdown setting and experiment with values for the pwm-lsb-nanoseconds parameter to find a value that best works for your display. Lower values give you a higher refresh rate that reduces pulsing/flickering but will cause more ghosting. Higher values reduce ghosting but will lower the refresh rate and could cause pulsing/flickering. You can also experiment with different brightness values. Reducing the brightness may get rid of the faint ghosting without sacrificing refresh rate.

I am not an FPP expert so I don't know if this is the best method to make these changes or not, but here is what I did to make the changes.

Code: [Select]
Start SSH Shell from the Help menu of FPP
Login using username: fpp and password: falcon

Type the following commands:

cd /opt/fpp/external/rpi-rgb-led-matrix/lib
sudo nano frambuffer.cc

modify the line that says “static const long kBaseTimeNanos = 130;” and change 130 to 300 (try different values between 130 and 300 to see what works best for your display)
Press ctl-o and hit enter. Press ctl-x

sudo nano Makefile

modify the line that says “DEFINES+=-DRGB_SLOWDOWN_GPIO=1” and change 1 to 2
Press ctl-o and hit enter. Press ctl-x

cd ..
sudo make

cd /opt/fpp/src
sudo rm fppd   (don’t worry if you get an error indicating file does not exit just continue to next step)
sudo make

close the SSH Shell
click restart FPPD in FPP
you may need to close the browser and reopen or reboot the Pi for the changes to take effect.

I still think it would be good if we could update the matrix library to the latest version and add these options to the LED panel settings.

I will be very busy getting other things ready so I don't if I will have any time to do any more with it before Christmas. But, the above changes at least seem to provide a working solution to the problem.
Title: Re: P10 panel flickering outline
Post by: Wichita on September 09, 2017, 02:04:00 PM
I have finally had some time to experiment with this some more and have made some progress.

The setting that seems to have the most effect is GPIO-slowdown. Changing it from 1 to 2 seems to completely get rid of the flickering pixels, but there is still some very faint ghosting especially on green and white. Changing the pwm_lsb_nanoseconds parameter from 130 to 300 completely gets rid of the ghosting but will decrease the refresh rate.

I recommend changing the GPIO-slowdown setting and experiment with values for the pwm-lsb-nanoseconds parameter to find a value that best works for your display. Lower values give you a higher refresh rate that reduces pulsing/flickering but will cause more ghosting. Higher values reduce ghosting but will lower the refresh rate and could cause pulsing/flickering. You can also experiment with different brightness values. Reducing the brightness may get rid of the faint ghosting without sacrificing refresh rate.

I am not an FPP expert so I don't know if this is the best method to make these changes or not, but here is what I did to make the changes.

Code: [Select]
Start SSH Shell from the Help menu of FPP
Login using username: fpp and password: falcon

Type the following commands:

cd /opt/fpp/external/rpi-rgb-led-matrix/lib
sudo nano frambuffer.cc

modify the line that says “static const long kBaseTimeNanos = 130;” and change 130 to 300 (try different values between 130 and 300 to see what works best for your display)
Press ctl-o and hit enter. Press ctl-x

sudo nano Makefile

modify the line that says “DEFINES+=-DRGB_SLOWDOWN_GPIO=1” and change 1 to 2
Press ctl-o and hit enter. Press ctl-x

cd ..
sudo make

cd /opt/fpp/src
sudo rm fppd   (don’t worry if you get an error indicating file does not exit just continue to next step)
sudo make

close the SSH Shell
click restart FPPD in FPP
you may need to close the browser and reopen or reboot the Pi for the changes to take effect.

I still think it would be good if we could update the matrix library to the latest version and add these options to the LED panel settings.

I will be very busy getting other things ready so I don't if I will have any time to do any more with it before Christmas. But, the above changes at least seem to provide a working solution to the problem.
Thank you, I will try this. I really appreciate the help. 

Sent from my SM-N920P using Tapatalk

Title: Re: P10 panel flickering outline
Post by: dkuntz on September 12, 2017, 07:27:30 PM
Just wanted to let you know this solution worked for me. I ended up with panels from two different suppliers. The first panels I got had a slight ghosting around text. These were the ones I posted before that lowering the voltage remedied. The panels from the other source had much worse issues with not only ghosting but major flickering of parts of the text. These were not fixable with voltage changes. Using both your changes has solved any issues with both sets of panels. Thanks!
Title: Re: P10 panel flickering outline
Post by: Wichita on September 12, 2017, 07:52:42 PM
That is very encouraging news. I haven't had a chance to try it yet. ( Work and family, don't they know what time of the year it is?).
Title: Re: P10 panel flickering outline
Post by: Wichita on September 13, 2017, 06:59:14 PM
This worked for me too.  Thank you, thank you, thank you.
Title: Re: P10 panel flickering outline
Post by: rmp2917 on September 30, 2017, 11:13:09 PM
I have made the necessary changes on my local setup to upgrade to the latest Pi RGBMatrix library and added the new settings to FPP. It seems to be working without any issues.

I would like to share this update with anyone that is interested. However, I am not sure what I need to do to push these updates to the server or how to create a new branch. If someone could let me know how to do this, I would be glad to share it.
Title: Re: P10 panel flickering outline
Post by: JonB256 on October 09, 2017, 10:39:50 AM
Making that last set of changes (from 130 to 300 and 1 to 2 ) removed almost all the flicker and ghosting.

Reducing brightness in LED Panels to 70% got rid of the rest of it. Thanks.
Title: Re: P10 panel flickering outline
Post by: Bshaver on November 01, 2017, 01:34:37 PM
I was able to make some progress with this issue. Since FPP is using an older version of the RGB Matrix library, the settings shown in the documentation that I mentioned earlier are not available.

I was able to find a constant in the code that controls the PWM Nanoseconds for LSB. I manually changed it and rebuilt FPP using the following.

Code: [Select]
cd /opt/fpp/external/rpi-rgb-led-matrix/lib
sudo nano framebuffer.cc

modify the following line "static const long kBaseTimeNanos = 130;" and change 130 to 300
Save the file and exit

sudo make
cd /opt/fpp/src
sudo rm fppd
sudo make

I then restarted FPP and ran some tests.

The ghosting is now gone for the most part. It still seems to show a little when the text is first displayed but goes away completely after a second. So, I don't know if there is something else in the code that needs changed.

Would it be possible to update the library to the latest version and add this as a setting on the matrix page? I would be willing to do this myself even it was only on my local copy, but I am not that familiar with Linux or the FPP code. So, I would probably need a lot of help.


Just a FYI: I finally..finally got around to doing this, and I can say that this change has made a big improvement to the aliasing / ghosting on my P10 panels.


I was seeing the aliasing on my panels through my color light board, and this resolved that as well.


Thanks for the help on this one!

Title: Re: P10 panel flickering outline
Post by: JonB256 on November 06, 2017, 09:37:00 AM
I had done the above change with good results (flickering at "end of string")

but did a re-install after a Texas sunshine temperature related crash. Started flickering again because it went back to "130" instead of "300"

If you are using a RasPi Matrix hat, I highly recommend this change. If you follow those instructions to the letter, it is worth it.
I only restarted FPPD when done and it worked fine. Didn't need to reboot.
Title: Re: P10 panel flickering outline
Post by: brichi on January 07, 2018, 07:28:05 PM
I have been trying to use the sudo nano frame buffer.cc line above but I get the following when I hit enter and I cannot edit anything or move forward




/
  GNU nano 2.7.4                                               File: framebuffer.cc                                               Modified 
                                                                                                                                           
// -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
// Copyright (C) 2013 Henner Zeller <h.zeller@acm.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation version 2.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://gnu.org/licenses/gpl-2.0.txt>
                                                                                                                                           
// The framebuffer is the workhorse: it represents the frame in some internal
// format that is friendly to be dumped to the matrix quickly. Provides methods
// to manipulate the content.
                                                                                                                                           
#include "framebuffer-internal.h"
                                                                                                                                           
#include <assert.h>
#include <ctype.h>
#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
                                                                                                                                           
#include "gpio.h"
                                                                                                                                           
namespace rgb_matrix {
namespace internal {
enum {
  kBitPlanes = 11  // maximum usable bitplanes.
};                                                                                                                                         
                                                                                                                                           
                                                                                                                                           
^G Get Help    ^O Write Out   ^W Where Is    ^K Cut Text    ^J Justify     ^C Cur Pos     ^Y Prev Page   M-\ First Line M-W WhereIs Next
^X Exit        ^R Read File   ^\ Replace     ^U Uncut Text  ^T To Spell    ^_ Go To Line  ^V Next Page   M-/ Last Line  M-] To Bracket

/

Title: Re: P10 panel flickering outline
Post by: brichi on January 07, 2018, 07:42:16 PM
not all pasted above, sorry but I don't see the line ""static const long kBaseTimeNanos = 130""



I searched every line, maybe the latest beta is different from 12/8/17? Is that just a Pi setting, Im using a BBB and have bad ghosting also
Title: Re: P10 panel flickering outline
Post by: rmp2917 on January 08, 2018, 05:08:40 PM
Use the arrow keys to scroll down to line 38. It should be 3 lines below the "kBitPlanes = 11".

This is only used on the Raspberry Pi. It will not effect the BBB.
Title: Re: P10 panel flickering outline
Post by: brichi on January 08, 2018, 05:17:09 PM
Thats what I figured once I looked more into the code, I have the BBB so im still stuck with a ghosting pixel issue
Title: Re: P10 panel flickering outline
Post by: JonB256 on January 08, 2018, 06:16:33 PM
Thats what I figured once I looked more into the code, I have the BBB so im still stuck with a ghosting pixel issue

What BBB code are you using?  The Dan Kulp series (I'm using 3 of them) does not ghost.

Version: v1.9-bbb-138-g53088307 (bbb-stretch-v1.x branch)

http://www.dankulp.com/bbb/    (9.2 beta, latest version)
Title: Re: P10 panel flickering outline
Post by: brichi on January 08, 2018, 06:20:29 PM
running the latest beta also, cant get this to work without the green following white - check it out here, I sound like crap cause im a little sick and the kids were going to bed so trying to stay quiet -  https://youtu.be/BnznhaxunZY (https://youtu.be/BnznhaxunZY)


I have 2 BBB, one is running latest beta and one running non beta, I swap the Octoscrolla between the 2 and get the same results, I wonder if the Octo is bad?


dkulp has been in a thread I created helping out so hopefully its something he can fix in code
Title: Re: P10 panel flickering outline
Post by: JonB256 on January 08, 2018, 06:23:52 PM
If it is the Octo (and its begingging to look like that) it sounds like a bad decoupling capacitor to me. They are those tiny little yellow dudes near every IC chip on every board.

In your video, the green seemed to be above and below the white, but your layout seemed to be horizontal, so that may not be the cap.
Title: Re: P10 panel flickering outline
Post by: dkulp on January 08, 2018, 06:28:29 PM
If it is the Octo (and its begingging to look like that) it sounds like a bad decoupling capacitor to me. They are those tiny little yellow dudes near every IC chip on every board.

In your video, the green seemed to be above and below the white, but your layout seemed to be horizontal, so that may not be the cap.


The octo's don't have them.  The Octo's are really simple, there is just one chip on it and that's it.  So it's either the chip or a solder joint.  Usually if it's one of those, then you get something much more noticeable, like an entire color not working or an entire line not working or similar. 


That said, it kind of does seem to be power related somehow.   
Title: Re: P10 panel flickering outline
Post by: brichi on January 08, 2018, 06:51:19 PM
so on a power end just so you know I am running a 5v/300watt and the BBB I tried running off that power supply and now I have it running off its own 5volt p/s just to eliminate that being the cause.

Title: Re: P10 panel flickering outline
Post by: Wichita on January 08, 2018, 07:56:37 PM
I didn't plan ahead last year and bought my panels from 2 different vendors. 10 from 1 and 2 from another.  The fix for the pi helped a bunch but the 2 odd panels have issues.  The one thing I noticed is that the input and output are different and a few components are different. The board numbers are identical.  My matrix is still mounted above the garage right now but I think the panels with issues had the connectors on the outside set of solder pads and the good ones it was on the inside set. Could be the other way around but I can't remember.  I don't know if that means anything but it did follow that the panels with issues.