power injection issue on my f16v3

[Lightsonthelake]

so after a move ive completely re done all my stuff. I dont have any issues with anything currently running. however I "upgraded " my mega tree. moved the pixels from 2 inch spacing to 1 inch. i was running 12 strands, i wanted to reduce the wiring. I have it reduced to 6 strands just looping my data wire.  im currently testing and my initial thought was I wanted to run a single cat 6 from my f16 to carry all my data. Then I would have one or twp power supplies at the base to supply my power. Here is where im having my issue. if i send power from my f16 it works. obviously it cant properly support 144 pixels.  if i send just data and use power supplies separate from my f16 pixels wont work. some will light up just solid white. i havent yet tried a different power supply as i tested and its putting out voltage. so i dont believe its my psu. any thoughts on where im failing at would be grateful.

[k6ccc]

Are you tying the negative on the power supplies with the negative from whatever is powering the F16?  It sounds like you are not.

[Lightsonthelake]

Are you tying the negative on the power supplies with the negative from whatever is powering the F16?  It sounds like you are not.

I am not. So share the negative, off the f16. Isolate positive. I'll do that. Thanks for the knowledge. 🫡

[k6ccc]

The data requires a return path back to the controller.  That would be the negative common wire (often incorrectly called "ground").  When you don't provide that path, the pixels have no signal reference so the lighting gets corrupted.

[Lightsonthelake]

I appreciate it fellas. Corrected my issue. Since it requires the return path. I have all my negative lines shared at my controllers with a bus bar. Would a single negative line work as a return for both my f16 and the expansion card? Also I have two power supplies per card too. I just want the minimum wires and connections as possible. Especially since I'm moving to deutsch connectors. 

[k6ccc]

I want to clarify where you are supplying power from and to.  My original understanding was that there was a power supply presumably near the F16 that was powering only the F16 (some distance from the pixel tree).  At the Pixel tree there is a couple of power supplies feeding the pixels themselves.  The solution to your problem was to tie the negative of the pixel tree power supplies to the negative of the F16 power supply.  In that arrangement a single return line to the F16 power supply would be fine since that is carrying very little current.

However, now you said that you were tying all the negatives together with a bus bar at the F16 - which defeats the purpose of reducing the amount of wire.  Or am I misunderstanding what you meant?  If that's the case can you describe it better where I was in error and / or add a drawing or picture to explain it better.

[Poporacer]

The AusChristmasLighting 101 Manual is a great resource and here is a diagram from it to better explain how power injection is typically used.

Where you are injecting you can use pre-made tees. One thing to note is that there are a ton of different types of tees so make sure you understand how they are actually wired. Some have the V+ pass through (for injecting from the same power source) or V+ not passing through (for injecting from different power supplies)
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[k6ccc]

Yep, that is a good reference as is the DIY Christmas piece on power.  The PI part starts about halfway down the page, but the earlier part is useful information for those that don't know it already.  I have both bookmarked.

https://www.doityourselfchristmas.com/wiki/index.php?title=Power_Injection

The full AusChristmasLighting 101 manual can be downloaded from:
https://auschristmaslighting.com/wiki/AusChristmasLighting-101

[Lightsonthelake]

I want to clarify where you are supplying power from and to.  My original understanding was that there was a power supply presumably near the F16 that was powering only the F16 (some distance from the pixel tree).  At the Pixel tree there is a couple of power supplies feeding the pixels themselves.  The solution to your problem was to tie the negative of the pixel tree power supplies to the negative of the F16 power supply.  In that arrangement a single return line to the F16 power supply would be fine since that is carrying very little current.

However, now you said that you were tying all the negatives together with a bus bar at the F16 - which defeats the purpose of reducing the amount of wire.  Or am I misunderstanding what you meant?  If that's the case can you describe it better where I was in error and / or add a drawing or picture to explain it better.

What is have is my f16v3 and expansion board with 4 power supplies in my attic. I use to run 12 cat 6 cables to my tree. So all my stuff in my attic is contained in an enclosure. Pi and fan controller are all contained in the box. My goal was to have just one cat 6 running to my tree. I could use 7 wires to feed data for my now 6 stands I'd have and one star. Using one or two power supplies at the base. Wiring at the tree would start data top to bottom with 120 pixels then bottom to top 120 pixels.

Using my new plan I'd be able to remove atleast 2 power supplies from my attic and use them at the props. Reducing heat and used space in my box. My house lights around my gutters and roof lines stay up year round.

So that being said in my box currently I have 1 psu for each half of a card (1-7, 8-16, 17-24, 25-32) each group of channels was on a single psu.

New changes would put f16 on one psu expansion card on second psu. Might even just drop to one psu. 


So to clarify on my second question, say my tree was using ports 14-16 on f16 using psu-a and ports 17-20 on expansion card psu-b. Both negative connections are tied to a bus bar before cards. Taking just data across 5 wires of a cat 6 and the remaining 3 wires tied into the bus bar.

My assumption with the knowledge of the negative completing a data circle it would not work that way. It would be data and negative per channel.

[k6ccc]

New changes would put f16 on one psu expansion card on second psu. Might even just drop to one psu.

Sounds like you are removing a lot of the power load from the F16, so should not be a big problem to reduce the number of power supplies to the F16 and expansion.  Obviously it depends on what is left on the attic controller.

So to clarify on my second question, say my tree was using ports 14-16 on f16 using psu-a and ports 17-20 on expansion card psu-b. Both negative connections are tied to a bus bar before cards. Taking just data across 5 wires of a cat 6 and the remaining 3 wires tied into the bus bar.

My assumption with the knowledge of the negative completing a data circle it would not work that way. It would be data and negative per channel.

Assuming you are using two power supplies for the pixel tree (mounted at or near the tree) via a power injection scheme, you would make sure the two negatives for those power supplies are connected to each other, AND there is a connection to the negatives of the power supplies in the attic.  That connection should have very little current as it is really only carrying the return signal from the pixels back to the F16.  However you listed 7 ports (not 5) of the controllers going out to the tree.  You should be able to do that on a single Cat-5 or 6, but that would only leave one wire for the return.  I would run a piece of zip cord (since most of us have that floating around) as the return line tie between the pixel tree power supply negative and attic power supplies negative.

One more question.  What is the wire length from the controller to the first pixel?  There is a limit to that.

With all that said, that is not how I would do it.  In my case my pixel tree (26 strings of 100 pixels in a flat tree configuration) and star of top (270 pixels in three string of 90 pixels) is using 29 ports of a F16v3 and 16 port expansion board.  It all runs at 5 volts.  The controller is mounted in a 12 x 12 x 6 PVC electrical box that is mounted behind the star.  There is another 12 x 12 x 6 PVC electrical box mounted to a structural cross member of the tree support that has the four power supplies.  There is about a six foot piece of 1 inch non-metallic flexible conduit connecting the two with the wires from the power supplies box to the controller box.  The result is that the pixel cables are only a couple feet long to both the pixel tree and star.  I run two pieces of Cat-5e from the house to the controller box.  One is the E1.31 LAN connection and the second is used for temperature probes in each of the two boxes from an environmental monitor in the attic.  That way I get an alarm E-Mail if the fan fails in either box.  And there is one 16 AWG extension cord that is hard wired into the power supply box that plugs into a convenient outdoor outlet box behind the tree.

[Lightsonthelake]

New changes would put f16 on one psu expansion card on second psu. Might even just drop to one psu.

Sounds like you are removing a lot of the power load from the F16, so should not be a big problem to reduce the number of power supplies to the F16 and expansion.  Obviously it depends on what is left on the attic controller.

So to clarify on my second question, say my tree was using ports 14-16 on f16 using psu-a and ports 17-20 on expansion card psu-b. Both negative connections are tied to a bus bar before cards. Taking just data across 5 wires of a cat 6 and the remaining 3 wires tied into the bus bar.

My assumption with the knowledge of the negative completing a data circle it would not work that way. It would be data and negative per channel.

Assuming you are using two power supplies for the pixel tree (mounted at or near the tree) via a power injection scheme, you would make sure the two negatives for those power supplies are connected to each other, AND there is a connection to the negatives of the power supplies in the attic.  That connection should have very little current as it is really only carrying the return signal from the pixels back to the F16.  However you listed 7 ports (not 5) of the controllers going out to the tree.  You should be able to do that on a single Cat-5 or 6, but that would only leave one wire for the return.  I would run a piece of zip cord (since most of us have that floating around) as the return line tie between the pixel tree power supply negative and attic power supplies negative.

One more question.  What is the wire length from the controller to the first pixel?  There is a limit to that.

With all that said, that is not how I would do it.  In my case my pixel tree (26 strings of 100 pixels in a flat tree configuration) and star of top (270 pixels in three string of 90 pixels) is using 29 ports of a F16v3 and 16 port expansion board.  It all runs at 5 volts.  The controller is mounted in a 12 x 12 x 6 PVC electrical box that is mounted behind the star.  There is another 12 x 12 x 6 PVC electrical box mounted to a structural cross member of the tree support that has the four power supplies.  There is about a six foot piece of 1 inch non-metallic flexible conduit connecting the two with the wires from the power supplies box to the controller box.  The result is that the pixel cables are only a couple feet long to both the pixel tree and star.  I run two pieces of Cat-5e from the house to the controller box.  One is the E1.31 LAN connection and the second is used for temperature probes in each of the two boxes from an environmental monitor in the attic.  That way I get an alarm E-Mail if the fan fails in either box.  And there is one 16 AWG extension cord that is hard wired into the power supply box that plugs into a convenient outdoor outlet box behind the tree.

My old house had several roof lines and windows. New house quite alot less. Plus I way over built for ideas of expansion. So reducing really is a must. 


I edited my post like 5 times because I kept seeing mistakes I was writing in. I actually originally had 6 strands and 2 negative lines. Then I realized I forgot my star and rather than adding data lines I subtracted because I was considering the negative to that. So yes your correct on my mistake there. I'll have 7 data lines in total. I'm even ok with placing 2 cat 6 cables it's still less than the 13 previously used. 



Length from controller to pixel is roughly 70ft. It works as it's how I've ran it for years before I'm not worried about the length of my data. I have only tested a single strand of 240 pixels with no issues so far. 


I had a smart reciever for my matrix, only down side to those is only 4 ports. Plus I'm having some issues with my smart receiver communication. I'm hoping I'm missing something simple and it's not actually broken. 


I had a similar plan but using pex since I have extra I won't be using. Placing that at the base to maintain a uniform circle.