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RPi + OpenELEC Flickering LEDs only with external grabber / Videos attatched

Discussion in 'Software Support' started by Manuel, 19 October 2018.

  1. Akriss

    Akriss Active Member

    Messages:
    449
    Hardware:
    RPi1/Zero, RPi2, RPi3, 32/64bit, +Arduino, +nodeMCU/ESP8266
    Hmmm..

    If possible, try attaching a computer monitor to the splitter (with tv attached) to see the image it's passing along to the converter.

    If its clear, then I would suspect the hdmi2av converter.

    Might be able to test the hdmi2av converter (and grabber) with something else that output's video with hdmi. A dvd player or a laptop with hdmi out, even a desktop computer.

    Could test the usb grabber with something that output to rca style connectors. A dvd player or camcorder maybe.
     
  2. Manuel

    Manuel New Member

    Messages:
    13
    Hardware:
    RPi3
    The splitter is definitely not responsible for the interference - because I already did plug in the external HDMI device directly to the Converter and the problem stays the same. Or what do you mean here? My english is good, but not perfect haha :)

    I tested other HDMI devices - the problem is still there.

    I am already trying to find a device which has a video output. So that I can plug in this device directly to the grabber (after that I can see if the problem comes from the converter or not)

    EDIT1:
    Okay, I did take an old Pi 1 (has a composite video slot) and connected it directly to the grabber (without converter and splitter). Unfortunately the problem stays the same, but the colorful lines are gone. See attatched picture of the grabber (on the old Pi 1 I also have installed Libreelec)
     

    Attached Files:

    Last edited: 9 November 2018
  3. Schimmi

    Schimmi New Member

    Messages:
    1
    Hardware:
    RPi3
    Hey, i have the same problem with my setup. I've got the APA102 but the problem is exactly the same. I already tried to switch out every part to see if one of them is causing the issue, but the problem still persists. My setup also worked flawlessly until a power outage a few months ago, after they fixed the power outage the problem started. An interesting fact is, that the flickering changes with the set frequency (e.g. high frequency = fast flickering and low frequency = slow flickering). Also i use double shielded cables for data and clock... so that's that.
     
  4. Akriss

    Akriss Active Member

    Messages:
    449
    Hardware:
    RPi1/Zero, RPi2, RPi3, 32/64bit, +Arduino, +nodeMCU/ESP8266
    All of the ground wires are tied together, correct?
    A loose ground wire can cause similar reactions.

    And with that, I'm out of ideas on a remedy.
    Sorry. :(. .
     
  5. Muriturus

    Muriturus New Member

    Messages:
    2
    Hardware:
    RPi3
    Hi, I had the same setup and flickering and solved it this way:
    Signal from Source (PC) is 60Hz. HDMI 2 AV converter is in NTSC mode. There is a little slider next to the power input. (NTSC is 59.94Hz). And set the value of the grabber property "standard" to "NTSC".

    So it might be the same for you that the input is 60Hz (likely if you are in the EU).

    Before the slider was on "PAL". Which works with 50Hz and can cause this kind of flickering due to different frequencies. Imagine it like someone talking too fast and you can understand most but not all of the words.

    Changing the baudrate, core_freq or other frequencies changed the behavior of the 'random' flickering. But did not lead to a solution for me.

    Now there is only a little flickering left in extreme situation like: left half of the screen black(#000000) and right half of the screen dark grey(#111111). Only the LED's right on the edge between these two colors are flickering a little bit. But that is due to the fact, that the converter does not provide a static output for a static input. Therefore true black input does not imply true black output. This flickering gets a little bit reduced by enabling the smoothing feature.
     
  6. Manuel

    Manuel New Member

    Messages:
    13
    Hardware:
    RPi3
    Hello Muriturus,

    thanks for your reply. I will imediately try that when I come home.

    But did I understand that right..? You want me to switch the slider of the HDMI 2 AV Conveter to NTSC? And furthermore change the grabber setting in the configfile to NTSC aswell?

    Thanks for confirming. I am not sure about this.

    BR

    Manuel
     
  7. Muriturus

    Muriturus New Member

    Messages:
    2
    Hardware:
    RPi3
    Yes exactly. If your source signal is 60Hz the slider on the HDMI 2 AV Converter should be on NTSC and the grabber setting in the configfile should be NTSC aswell.
     
  8. Manuel

    Manuel New Member

    Messages:
    13
    Hardware:
    RPi3
    Hello Muriturus,

    I did try that, but that did not help :-(

    For your information.. I also have this problem when I use external ambilight only with the grabber and not with converter and splitter.

    Thanks for your help

    BR

    Manuel
     
  9. Jens56

    Jens56 New Member

    Messages:
    3
    Hardware:
    RPi2, RPi3
    Hi all,
    i am running into exactly the same problem ... i got an RPi 2 with APA102 ...
    On bright scenes, no problem but on darker scenes there is a nervous flickering on some LEDs, especially the non-white ones.
    I tried / changed nearly everything. There is no flickering on my captured image. If i freeze the screen you can see it very clearly. This must be some interference stuff impacting the grabber chain since there is no problem with testing internal grabber or setting solid colors from hyperion client. Ill try the ntsc workaround but i am pretty sure that will make no difference ...
     
  10. Jens56

    Jens56 New Member

    Messages:
    3
    Hardware:
    RPi2, RPi3
    okay, with change to NTSC: no approvement ... :(

    As a side note: I already ran this setup with a WS2812B Strip with no problems ... this may have to do something with the APA102 ... but i dont know what :/
     
  11. Grunge

    Grunge New Member

    Messages:
    2
    Same issue with apa102 from aliexpress. I tried with a raspberry zero + level shifter and then with a esp8266. Always the same issue :(
     
  12. Grunge

    Grunge New Member

    Messages:
    2
    Might have found something when testing the stream from the grabber. It produces a lot of noise that could lead to make Hyperion creates that flickering. Maybe a faulty UTV007 or HDMI to rca...
     
  13. Jens56

    Jens56 New Member

    Messages:
    3
    Hardware:
    RPi2, RPi3
    Got also APA102 from Aliexpress .. my grabber does not produce that noise so much ... i am sure, that has something to do with the software and not with hardware since the internal grabber and solid colors are very stable, no matter which brightness or speed ...
     

    Attached Files: