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RPi + Other Software LEDs (red color) issue

Discussion in 'Hardware Support' started by Limbids, 13 March 2018.

  1. Limbids

    Limbids New Member

    Messages:
    2
    Hardware:
    RPi3
    Hi All, I have installed some components on my TV last weekend and running into issue with the LEDs.
    I have tried to find something on this forum and also reconnected (re-soldered) some wires, but still having issues.
    Hope someone here recognizes my situation below.

    I am not home at the moment, so apologies for the lack of photos / logs / files etc.
    Please let me know what can help and I will provide more info later.

    For now let me describe my problem.

    Setup:
    RPi 3 + Raspbian Stretch Lite + Hyperion
    APA102 LED strip (+/- 3 meter)
    (HDMI>AV converter + UTV007 grabber and 5V15A PSU for LEDs)

    Situation:
    I have just installed Raspbian and Hyperion and created a Hyperion configuration file. Now I am trying to test the strip with the Hyperion color wheel to see if everything is working as expected, which it is not in my opinion:)

    1) After booting the RPi3 the Rainbow Swirl shows rainbow colors (all LEDs are lighting up) but the swirl does not move.

    2) Trying RGB colors in Hyperion color-wheel:
    • setting Blue (0/0/255) gives me a solid blue --> OK
    • setting Green (0/255/0) gives me a solid green --> OK
    • setting Red (255/0/0) gives me a blue with red flickering between it (when setting something like 214/0/0 then it shows some "solid" red)
    • With the settings above going round the color wheel, the bottom half (blue via turquoise to green) is working OK. The top half (green via yellow to red and on to blue) gives me erratic flickering of the LEDs, mainly showing blue with some small flickering hint of the intended color.
    So now I am not sure if my connections are not soldered correctly or it is in software driving the LEDs or any other problem.
    As said, hope someone can point me in the right direction.

    Thanks in advance already!
     
  2. Akriss

    Akriss Active Member

    Messages:
    322
    Hardware:
    RPi1/Zero, RPi2, RPi3, 32/64bit, +Arduino, +nodeMCU/ESP8266
    All of the Hyperion setups I have constructed with APA102's have worked flawlessly wile using a level shifter to boost the 3.3 volt signal level of the RPI's GPIO's to 5 volts. (74AHCT125 or 74AHC125 works great) The APA102 are specified to use a 5 volt signal (-/+ about 3%).

    That being said, I noticed you may be able to just use the apa102's wile connected directly to the GPIO's for a small numbers of led on a strip,. But I always found it necessary to use a level shifter on big (and small) strips if I wanted no flickering and no other led strangeness.
     
    • Like Like x 1
  3. Raijeru

    Raijeru New Member

    Messages:
    9
    Hardware:
    RPi3
    Akriss, can u show ur connection with level shifter, grabbers etc.?
    Maybe level shifter is a issue with my case also but i am not much into all this things so it's like a black magic for me right now.

    I would be really grateful.
    Cheers.
     
  4. Akriss

    Akriss Active Member

    Messages:
    322
    Hardware:
    RPi1/Zero, RPi2, RPi3, 32/64bit, +Arduino, +nodeMCU/ESP8266
    • Like Like x 1
  5. Limbids

    Limbids New Member

    Messages:
    2
    Hardware:
    RPi3
    Thanks for this suggestion! Totally forgot About level shifter. After research I though not needing one, but looks like I do. Going to try that.
    When I know more I Will post back.
    Could be some time though if I have to order in China
     
  6. Lyr3x

    Lyr3x New Member

    Messages:
    9
    Hardware:
    RPi1/Zero, RPi2, RPi3, +Arduino, +PhilipsHue
    Did you solved the problem? Im fighting this issue with my apa102 aswell. There is no difference between using the 74AHCT125 or not. When using mixed colors like a sand color or orange/yellow the leds starting flicker, which is really annoying

    My Setup:
    209 LEDS
    Power supply added to both ends
    GND connected to pi as well
    Everything is soldered fine