Flickering issue on 5V pixels

SamJ

New elf
Joined
Oct 3, 2021
Messages
23
Location
Dallas, TX, USA
Kulp16A-B controller. The pixels on the 5' and 10' extensions are having issues. Everything is set for 15% power, so I don't think it's a current issue. The same channel outputs work fine without the extensions.

 

SamJ

New elf
Joined
Oct 3, 2021
Messages
23
Location
Dallas, TX, USA
No, I didn’t think it would be necessary for such a short distance. If the controller can’t send a signal 10 feet it’s a little disappointing. That would also make my plans to use this for a house outline much more complicated.
 

Notenoughlights

260,000+ twinkly lights
Generous elf
Joined
Oct 16, 2016
Messages
250
Location
Christchurch, New Zealand
I don't know much about the kulp controller line, but if it hasn't got a level shifter on its output for the data line, the signal can degrade fast leading to issues. Have you tested the extension cables on each output or a different controller if you have one to rule out the cable being faulty?
 

SamJ

New elf
Joined
Oct 3, 2021
Messages
23
Location
Dallas, TX, USA
Unfortunately I don’t have any other controllers to compare. The flickering is similar on all channels with the cables.
Resistance through both cables is .7-.9 ohms on all conductors.
 

Mark_M

Annoying Elf
Generous elf
Joined
Dec 30, 2018
Messages
652
Location
Christmas Light world
Kulp16A-B controller. The pixels on the 5' and 10' extensions are having issues. Everything is set for 15% power, so I don't think it's a current issue. The same channel outputs work fine without the extensions.

I'm seeing most flicking during white when R, G, B LEDs inside the pixel are on, that is the highest power draw state.
My first step would be checking voltage at the ports on the controller.

It is such a short distance and many Kulp's have been sold, I highly doubt you have a data output issue.
 

BAZMick

Full time elf
Generous elf
Joined
Nov 26, 2019
Messages
276
Have you tried at 30-50% brightness to see if it's still flickering?
 

SamJ

New elf
Joined
Oct 3, 2021
Messages
23
Location
Dallas, TX, USA
Voltage is good - 5.02 at the board. Here’s another video of strangeness with just the 18” pigtails. Even at the end of the flickering string I see voltage at 4.7 or higher.
I’ve watched the VCS video on flickering lights and don’t recognize any of the issues that he discusses in my setup.

 

Mark_M

Annoying Elf
Generous elf
Joined
Dec 30, 2018
Messages
652
Location
Christmas Light world
Voltage is good - 5.02 at the board. Here’s another video of strangeness with just the 18” pigtails. Even at the end of the flickering string I see voltage at 4.7 or higher.
I’ve watched the VCS video on flickering lights and don’t recognize any of the issues that he discusses in my setup.

4.7v volts is getting low. Time for power injection.
 

SamJ

New elf
Joined
Oct 3, 2021
Messages
23
Location
Dallas, TX, USA
Tried resetting all outputs to 30% and removing the extensions. I had some flickering with the RGB cycle test on output 16. RGBW test caused all outputs to freeze like this.
A260ECC4-A4D4-4178-ACFC-BBF44238A133.jpeg
 

Mark_M

Annoying Elf
Generous elf
Joined
Dec 30, 2018
Messages
652
Location
Christmas Light world
It should be able to run 50 pixels without injection though, right?
I reckon your power supply is just a touch too low or there is too much resistance in the extensions you have. About 50 pixels is usual power injection for 5v.
 

SamJ

New elf
Joined
Oct 3, 2021
Messages
23
Location
Dallas, TX, USA
See if you can measure the voltage on the data line coming out of the controller. This may tell us if a level shifter is used.
I get 0V on the data line right now and the controller says that it’s still sending the RGBW test signal. That could be my cheap multimeter not being able to pick up the signal due to change rate.
 
Top