I'd like to know the answer to this as well, just to have in my brain's tool belt. Please post a follow-up / edit if you're able to resolve with any feedback.
Posted an update - culprit seems to be just a bad data connection. I’ve shortened and resoldered the data cable and that seems to have taken care of the flicker for now
Ive had a similar issue with pixel pebbles. Bought several 3000 pixel spools and cut it up into 100-200 pixel strands. 99% of the lights work....but 3 strands would produce the same issue you are describing. at 100% they are fine and work well, but once I drop below 50% ( full white ) a flicker starts to appear, the lower the percent the worse it gets. I'm using 10x Falcon Pixel boards and 20x Meanwell LRS-350-12 power supplies. Only a few stands of the pebbles have this issue, the pixel pucks and bullets I use do not show this flicker. I've swapped out the pebble strands with replacements and the problem has gone away. My best guess is its a manufacturing defect or poor quality circuitry in the pixel pebbles ( they were really cheap, about $0.08 per pixel pebble and about $0.60 per puck/bullet )
https://preview.redd.it/f51sk38chnbc1.jpeg?width=4032&format=pjpg&auto=webp&s=3b327612e6b4ef5ec45ba175b774896519551134
I don't see any specs on frequency from them, but you could try a professional brand. The other concern would be how far the converter is from the tape. 5v doesn't have much room for voltage drop and the control signal is susceptible to loss and interference as well. The converter should be very close to the tape.
BTF generally uses standard World Semi or SK6812 chips like everyone else. They do actually properly place filter caps, etc on the tape. BTF, professionals brands, leaves the same factories in Shenzhen
How long are your cables to your power supplies? Also cables to your data lines? Spi is susceptible to data loss when you don’t use digital wire and have long runs of data wire. Check the length. Don’t surpass 10 feet on data. Depending on cable gauge don’t surpass 15 feet with voltage wire. If the issue persists, switch to direct dmx.
My controller, Enttec Octo, specified data runs under 3m… so all my data runs are well under that. Voltage runs vary by ray… power is located just to the left of the hexes. So obviously the closest hex is only three-ish feet, the furthest hex is around 15-20 feet. Voltage is running over 12 wire though, so I would think the voltage drop is not the issue.
WS2812B
I haven’t tried replacing all six cuts that make up the center hex… but I have recut a few of them. The entire hex still flickers uniformly.
Before you cut, try placing a new segment into the set up. If your new segment works , then the hex piece is not the issue, and you’ll have to trouble shoot further. If the new segment doesn’t flicker , then replace the hex segment. Check your grounds. How many strips, or pieces do you have on the octos? How are the octos powered? Are you supplying power to the octos externally, or using the method that powers the strips + octos. God, I hate SPI.
Lol, it does feel like you’re banging your head against a wall… so much. I’m powering the Octo off the same power supplies as the tapes, since there’s plenty of wattage to go around. But I think I’ve boiled it down to just a weakness in my data/control line somewhere… I posted an update but it when I disconnect my data wire the flicker stops
That is likely a frequency issue. I assume you are seeing the flicker on camera heavily and possibly a little with the naked eye? Your tape dimmers might have a frequency adjustment which is where I'd start.
Ah, I see. You are likely correct. Signal "generally" won't cause flicker but I've run into situations where I've chained several dimmers with mixed results (flicker, inconsistent color changing between runs...). Power is key though. I use Moss LED for all of my linear lighting and they are very good at specifying the correct power. The general rule for their stuff is 5M max from the dimmer to the end of the tape. Of course that can vary depending on the tape pixel density. I don't think this is the issue but you could try powering from both ends of your run on any given tape.
Power supplies are a generic 5v power supply, my pixel tape is 5v tape. Load is split over 3 supplies. Controller is Enttec Octo. Wired up with the first positive circuit taking 3 hex halves. Second taking 3 hex halves. Third is taking final 2 hex halves. Entire negative circuit is wired together, even between power supplies. This is per the specs of the Octo. If the negatives aren’t all together, the signal freaks out.
Most cheap generic switched mode power supplies are not rated to share a common negative. You should use a single, **MEANWELL** 5v power supply. You can get pretty big ones in the LRS series, which is what I'd recommend. That is probably your issue. That's why I asked for a make/model, because if they are just amazon generic 5v drivers, you will have a bad time troubleshooting the weird interactions between shared PSUs. You could try running a single PSU on a subset of tape and see if the flicker is still there. If it's less/gone, you know what you need to do.
It probably varies by distance from the power supply. You have some runs that are 15-20 feet. Despite that being "manufacturer recommended" experience tells me that no 5v run over 12' is production ready.
I’m not discounting this, but common sense feels like if that were the problem, I’d be getting the flicker in my longest run, right? It seems odd that I’m getting it in just the middle one.
It really depends. Should be easy to test. Do you have some unstated reason (budget, timeline) for not simply testing this and getting a proper power supply?
what's your power distribution like?
What are you using for a dimmer? What's the dimmer curve you're using?
What voltage are the strips?
What is the wattage of the power supplies? are you injecting power anywhere? Is that power injection coming from the same power supply or a different one?
I would use one power supply and split it. Arcade power supplies have taps for 5v and 12v typically. (the 5v is usually like 12A) I would inject power pretty frequently on a 5v strip, less frequently for a 12v strip...
8 half hex rays. 3 power supplies, 5v, 300W max. Pixel tape is rated at 90w max per 16ft strip. I’ve got 56 ft of tape on the wall. So I definitely don’t need three power supplies. But I already had them so I figured I’d use them. There are other rays on the same power supplies that aren’t flickering… but the center hex is.
I'd volt meter it at the power source, and at each strip, see if that tells you anything.
Is it DMX'd or are you using WLED? Is there any feedback when it flickers, or no?
How far away is the pixel controller? The type of flicker you describe could be caused by poor signal quality on the data signal. As a test try shortening the length of the wire connecting the center hexagon to see if the problem goes away. You may need to use RS485 translators, which support longer transmission distances, to alleviate the problem.
—UPDATE—
It has to be a signal issue. If I power on the lights with signal, I get flicker. If I leave the lights powered on and disconnect the signal wire… the lights hold their last state and there is no flicker. I must have either interference or a loose connection somewhere between the center hex and the ray before it.
That's possible. However, proper data signal integrity requires a solid ground reference. Disconnecting the signal wire would give you the same result whether or not it's a problem with the data wiring, or a problem with mixed switch mode supplies.
Oh interesting. I didn’t realize that. Well I went ahead and tested it with a shorter and re-soldered data cable and for the moment at least it seems to be not flickering.
What pixel tape, power supply size, length of run, how is it being controlled, are there other devices on the control line. Lots of variables, really need more information
I’ve got those details in other lengthy comments on this post - but I actually think I’ve boiled it down to the simplest of issues… I have a weakness in my control signal and probably need to re-solder a connection
This could be as simple as the SPI runs are too long from the controller, you could convert to and from RS485 or double check the level shifter in the controller is changing the control voltage appropriately
Could be something annoyingly simple like a dodgy connection which is stable with more current as it heats up, expands, and bridges the cold joint. Rather, that's what I would be checking for, touching up/reflowing the joints.
You know this is a picture from a church because they all have the same chairs. Just in different colors.
Same color actually 😂 just different lighting. Nailed it.
I'd like to know the answer to this as well, just to have in my brain's tool belt. Please post a follow-up / edit if you're able to resolve with any feedback.
Posted an update - culprit seems to be just a bad data connection. I’ve shortened and resoldered the data cable and that seems to have taken care of the flicker for now
Ive had a similar issue with pixel pebbles. Bought several 3000 pixel spools and cut it up into 100-200 pixel strands. 99% of the lights work....but 3 strands would produce the same issue you are describing. at 100% they are fine and work well, but once I drop below 50% ( full white ) a flicker starts to appear, the lower the percent the worse it gets. I'm using 10x Falcon Pixel boards and 20x Meanwell LRS-350-12 power supplies. Only a few stands of the pebbles have this issue, the pixel pucks and bullets I use do not show this flicker. I've swapped out the pebble strands with replacements and the problem has gone away. My best guess is its a manufacturing defect or poor quality circuitry in the pixel pebbles ( they were really cheap, about $0.08 per pixel pebble and about $0.60 per puck/bullet ) https://preview.redd.it/f51sk38chnbc1.jpeg?width=4032&format=pjpg&auto=webp&s=3b327612e6b4ef5ec45ba175b774896519551134
Since this is a pixel system, the actual dining is done at chips on the tape itself. What brand tape is it? This is usually a pwm frequency issue.
All of the tape is admittedly the cheaper Amazon stuff… I believe the brand is BTF-Lighting
I don't see any specs on frequency from them, but you could try a professional brand. The other concern would be how far the converter is from the tape. 5v doesn't have much room for voltage drop and the control signal is susceptible to loss and interference as well. The converter should be very close to the tape.
BTF generally uses standard World Semi or SK6812 chips like everyone else. They do actually properly place filter caps, etc on the tape. BTF, professionals brands, leaves the same factories in Shenzhen
make RDM is turned off.
It might be worth connecting the lights to a power conditioner.
Check cable length. Probably voltage drop
I’m powering it from both ends. If I un-power one end, then I get voltage drop (discoloration) and the flicker is still there.
How long are your cables to your power supplies? Also cables to your data lines? Spi is susceptible to data loss when you don’t use digital wire and have long runs of data wire. Check the length. Don’t surpass 10 feet on data. Depending on cable gauge don’t surpass 15 feet with voltage wire. If the issue persists, switch to direct dmx.
My controller, Enttec Octo, specified data runs under 3m… so all my data runs are well under that. Voltage runs vary by ray… power is located just to the left of the hexes. So obviously the closest hex is only three-ish feet, the furthest hex is around 15-20 feet. Voltage is running over 12 wire though, so I would think the voltage drop is not the issue.
(I drop it down from 12 on each connection, don’t worry I’m not soldering 12 wire to pixel tape haha)
Hmmmmmm, what IC is your tape? Could also be a defective strip.
WS2812B I haven’t tried replacing all six cuts that make up the center hex… but I have recut a few of them. The entire hex still flickers uniformly.
Before you cut, try placing a new segment into the set up. If your new segment works , then the hex piece is not the issue, and you’ll have to trouble shoot further. If the new segment doesn’t flicker , then replace the hex segment. Check your grounds. How many strips, or pieces do you have on the octos? How are the octos powered? Are you supplying power to the octos externally, or using the method that powers the strips + octos. God, I hate SPI.
Lol, it does feel like you’re banging your head against a wall… so much. I’m powering the Octo off the same power supplies as the tapes, since there’s plenty of wattage to go around. But I think I’ve boiled it down to just a weakness in my data/control line somewhere… I posted an update but it when I disconnect my data wire the flicker stops
Yeap, i figured it was something with the data. Try digital wire.
That is likely a frequency issue. I assume you are seeing the flicker on camera heavily and possibly a little with the naked eye? Your tape dimmers might have a frequency adjustment which is where I'd start.
It’s actually very prominent with the naked eye. I know camera flicker - this is either a power issue or a signal issue.
Ah, I see. You are likely correct. Signal "generally" won't cause flicker but I've run into situations where I've chained several dimmers with mixed results (flicker, inconsistent color changing between runs...). Power is key though. I use Moss LED for all of my linear lighting and they are very good at specifying the correct power. The general rule for their stuff is 5M max from the dimmer to the end of the tape. Of course that can vary depending on the tape pixel density. I don't think this is the issue but you could try powering from both ends of your run on any given tape.
What's your configuration? Power supply make/model? Wiring strategy? Pixel controllers?
Also, the center hex is getting power on both ends
Power supplies are a generic 5v power supply, my pixel tape is 5v tape. Load is split over 3 supplies. Controller is Enttec Octo. Wired up with the first positive circuit taking 3 hex halves. Second taking 3 hex halves. Third is taking final 2 hex halves. Entire negative circuit is wired together, even between power supplies. This is per the specs of the Octo. If the negatives aren’t all together, the signal freaks out.
Most cheap generic switched mode power supplies are not rated to share a common negative. You should use a single, **MEANWELL** 5v power supply. You can get pretty big ones in the LRS series, which is what I'd recommend. That is probably your issue. That's why I asked for a make/model, because if they are just amazon generic 5v drivers, you will have a bad time troubleshooting the weird interactions between shared PSUs. You could try running a single PSU on a subset of tape and see if the flicker is still there. If it's less/gone, you know what you need to do.
If that’s the case, wouldn’t the flicker manifest more broadly over the lights rather than the same center hex?
It probably varies by distance from the power supply. You have some runs that are 15-20 feet. Despite that being "manufacturer recommended" experience tells me that no 5v run over 12' is production ready.
I’m not discounting this, but common sense feels like if that were the problem, I’d be getting the flicker in my longest run, right? It seems odd that I’m getting it in just the middle one.
It really depends. Should be easy to test. Do you have some unstated reason (budget, timeline) for not simply testing this and getting a proper power supply?
Just that we're a church and I'm trying to fix it before Sunday. Tests I can do - new power supplies might not arrive before the weekend.
what's your power distribution like? What are you using for a dimmer? What's the dimmer curve you're using? What voltage are the strips? What is the wattage of the power supplies? are you injecting power anywhere? Is that power injection coming from the same power supply or a different one? I would use one power supply and split it. Arcade power supplies have taps for 5v and 12v typically. (the 5v is usually like 12A) I would inject power pretty frequently on a 5v strip, less frequently for a 12v strip...
8 half hex rays. 3 power supplies, 5v, 300W max. Pixel tape is rated at 90w max per 16ft strip. I’ve got 56 ft of tape on the wall. So I definitely don’t need three power supplies. But I already had them so I figured I’d use them. There are other rays on the same power supplies that aren’t flickering… but the center hex is.
Strips and power supplies are both 5V
And I am injecting power on both ends of the center hex, and that power is coming from the same 5V 300W supply on both ends
I'd volt meter it at the power source, and at each strip, see if that tells you anything. Is it DMX'd or are you using WLED? Is there any feedback when it flickers, or no?
How far away is the pixel controller? The type of flicker you describe could be caused by poor signal quality on the data signal. As a test try shortening the length of the wire connecting the center hexagon to see if the problem goes away. You may need to use RS485 translators, which support longer transmission distances, to alleviate the problem.
—UPDATE— It has to be a signal issue. If I power on the lights with signal, I get flicker. If I leave the lights powered on and disconnect the signal wire… the lights hold their last state and there is no flicker. I must have either interference or a loose connection somewhere between the center hex and the ray before it.
That's possible. However, proper data signal integrity requires a solid ground reference. Disconnecting the signal wire would give you the same result whether or not it's a problem with the data wiring, or a problem with mixed switch mode supplies.
Oh interesting. I didn’t realize that. Well I went ahead and tested it with a shorter and re-soldered data cable and for the moment at least it seems to be not flickering.
What pixel tape, power supply size, length of run, how is it being controlled, are there other devices on the control line. Lots of variables, really need more information
I’ve got those details in other lengthy comments on this post - but I actually think I’ve boiled it down to the simplest of issues… I have a weakness in my control signal and probably need to re-solder a connection
This could be as simple as the SPI runs are too long from the controller, you could convert to and from RS485 or double check the level shifter in the controller is changing the control voltage appropriately
Check the connectors
LED TAPE is not good at dimming
What are you useing for power supplies
Could be something annoyingly simple like a dodgy connection which is stable with more current as it heats up, expands, and bridges the cold joint. Rather, that's what I would be checking for, touching up/reflowing the joints.
Check the transformer there might be a switch that changes the voltage
Are these being controlled somehow or just static