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SOLVED Bad LEDs? APA102 Uncontrollable LED blinking

Discussion in 'Hardware Support' started by Alpha7, 10 January 2021.

  1. Alpha7

    Alpha7 New Member

    Messages:
    12
    Hardware:
    RPi1/Zero
    I wanted to setup a TV backlight with APA102 LEDs my pi Zero and Hyperion. I ordered the LED's configured the system and as soon as the LED's arrived I hooked them up to my Zero and everything was great.

    I moved the LEDs from the spool to my TV and fired the entire setup again with my grabber and everything configured and I had a short or something somewhere as my power supply start clicking. I took it all apart again, moved the pi and power supply to 4 LED's that I had cut from the original spool (that were not connected during the short) and the LED's just go crazy. They blink random colors and brightness's at varying frequencies.

    I thought okay, maybe I damaged the GPIO pins on the pi Zero so I loaded Hyperion on an old Pi 1 I had lying around and I get the exact same problem with those LED's

    On my Pi 1 which I currently have hooked up I have pin 19 (GPIO 10) running to the DI on my LEDs and pin 23 (GPIO 11) running to to the CI on the LEDs.

    I am powering the pi with the USB adapter but the LED's with my 5v 12A power supply.

    If I power up just the LEDs they do nothing, as soon as Hyperion or the GPIO pins starts initializing the LEDs start going berserk. While I did have this all working I have re-installed Hyperion a couple of times to try to rule out software issues.

    I currently have the controller type set to apa102, with the default SPI path of dev/spidev0.0 and the baud rate of 100000 and 4 LED's in my top row. I don't think any other settings really should affect the LEDs themselves. Even if I turn off the LEDs in Hyperion it doesn't stop the LEDs from going crazy. Trying different effects doesn't change anything with the LED's.

    I am hoping to get these extra 4 LEDs working before I go back to the installed LED's on my TV. Any suggestions would be appreciated.

    My colors on my wiring are all off and I have a connector that uses different wires with different colors. I used paint to take the CI and DI cables blue and green to make things easier.

    20210110_120615.jpg
     
  2. jeroen warmerdam

    jeroen warmerdam Raspberry 3B / APA102 / Hyperion.NG relaisbox

    Messages:
    433
    Hardware:
    RPi3
    what i would do, go to webUI localip:8090 and turn of the dispmanx and usbgrabber and then check again.
    you can increase setting of SPI to 1500000

    it looks like the leds are displaying static noise on the dispmanx video input of hyperion.


    if thats doesn;t help then connect GND from and to your PI from PSU
    stabilize your grounds (GND -) because you are using 2 different PSU
     
  3. jeroen warmerdam

    jeroen warmerdam Raspberry 3B / APA102 / Hyperion.NG relaisbox

    Messages:
    433
    Hardware:
    RPi3
    i would always recommend to use the same PSU that what you have is 12A or 60Watts is more then enough to power everything

    so; Raspi and ledstrip and grabber on same PSU ground everything and test again :)
     
  4. Alpha7

    Alpha7 New Member

    Messages:
    12
    Hardware:
    RPi1/Zero
    I had the PSU running the Pi Zero but just wanted a "quick test" lol. I can get those connections soldered here shortly.

    I do currently have the USB Grabber and the screen capture output disabled. I upped the Baudrate but so far the same thing. I'll update again once I get the PI powered off the same PSU.
     
  5. jeroen warmerdam

    jeroen warmerdam Raspberry 3B / APA102 / Hyperion.NG relaisbox

    Messages:
    433
    Hardware:
    RPi3
    you can calculate power , how much leds?

    lets say 200 leds so, 200 x 0,048A = 9,6A

    the clicking of your PSU is protection against shortcutting probably, your grabber can also be responsible for a strange voltage thus its connected to electronics.
    also test without the grabber to rule out wrong connections
     
  6. Alpha7

    Alpha7 New Member

    Messages:
    12
    Hardware:
    RPi1/Zero
    When my PSU clicked I'm pretty sure I had a short, none of the LED's I actually have on the TV ever lit up. I have about 300 LEDs but I am planning to run them at 50% brightness to start then check draw - I already have this set in hyperion. That is assuming is actually equal to 50% power as well? .0.24A * 300 = 7.2A

    I did just get the Pi hooked up via the power supply and its working again.. hot dang, thank you for that suggestion.

    Small problem now though if you have any further ideas. The LEDs are all working however I am getting an unwanted blue randomly showing up every few seconds randomly throughout the strand. If I run the Knight Rider test for example that pulses red back and forth some of the LEDs will light up blue for a split second - it could be LEDs that are lit red running the test or other ones that should be off.
     
  7. jeroen warmerdam

    jeroen warmerdam Raspberry 3B / APA102 / Hyperion.NG relaisbox

    Messages:
    433
    Hardware:
    RPi3
    thats a strange one, if every led is responsive and you configured LED layout correct, also use the arrow correct of dataflow..

    mmm let me think...
    lower or higher the SPI output
    calibrate the gamma and colours upto your likings
    measure the volts on your PSU, not go over 5 or way under, like 4,9 volts is perfect.
    make sure everything including the ledstrip is connected to GND so PI to PSU/ PSU to ledstrip / ledstrip to PI

    it can also be the GPIO output which cannot "rest" put in series on the pinout a 150ohm resistor for instance. ( you can find that on forum here)

    if that doesn't help use a level shifter ( no experience with those) but they make sure a clean data flow to the lights :)

    thats what i can come up with, and kuddo's that you got it working again! thats one worry less
     
  8. jeroen warmerdam

    jeroen warmerdam Raspberry 3B / APA102 / Hyperion.NG relaisbox

    Messages:
    433
    Hardware:
    RPi3
    yes somewhat in that ballpark, give or take

    i think also when you run them at full brightness the total draw from your PSU will be 14,5amps excluding the PI and the rest.
    so you will come at a good 15Amps at 5 volts. Then its good to use a 100 Watts PSU that can deliver 20Amps so you will be 'safe'

    my friend has your setup with APA102 ledstrip 300 of them almost (60L/mtr) and run them at only max 70% because its too bright > lights the whole room.
     
    • Like Like x 1
  9. Alpha7

    Alpha7 New Member

    Messages:
    12
    Hardware:
    RPi1/Zero
    Solved

    Okay... So for anyone that might experience the same issue, if its possible to get things as screwed up as what I did :crying:

    First issue, when I shorted my power supply I apparently blew a resistor or level shifter that is built into the APA102 LEDs, they were initially covered by the wiring jacket that came with the LEDs and are only present at the very beginning of the strand. This was preventing any data (from what I can tell) from passing to the DI and/or CI pins from the PI. I spliced out the first LED behind my TV with the beginning on another APA102 strand that I had and after doing so I got one LED to light up.

    Second issue, so now I have my first LED lit, but my other 300 or so doing nothing. After inspecting my LEDs I noticed that my 8th or so LED in the strand was lit very very faintly blue. I figured this LED (or potentially the one before or after it) might be as far as the short got blowing out the LED controllers. I also spliced in another 10 LEDs to be safe and after doing that my entire strand finally lit up. I was never able to find a way to test the controller each individually and didn't want to splice one by one which is why I just did the 10 all at once.


    Jeroen was likely right on when he mentioned a level shifter about my test LEDs lighting up random colors after I got my little 4 LED long test strip working, that of course was cut off and did not have a level shifter/resistor (whatever comes with the APA102s) which is what caused the LEDs to be working but to also light up additional bad colors.

    I never tried powering the Pi thru USB power with the LEDs connected with the level shifter/resister on the LED strip working but its definitely cleaner to power the pi and the LEDs with the same power supply. Please excuse my ignorance on the level shifter/resister on the LEDs. The components are so small I can barely them. I also fixed some connections on my pi Zero and I am using that as the Pi1 couldn't handle the USB capture and would cut out and have delays of 10+ seconds on controlling the LEDs.