So, every now and then, I switch effects or something, and the unit resets itself (Lights turn back to orange) and the web interface tells me “Connection to LED failed” or something similar, I can’t recall the exact wording of the error message.
The same thing happens on several other of my WLED devices, but not quite as often as the one I just installed.
In addition, effects are not working “Properly”… at least after adding segments. I add a segment, and set it to “blink” for example, it will blink on and off, but will have some “ghost” blinks in there. Turns off, turns on and then flickers erratically, then turns off. Then turns on, flickers erratically, then off again.
It was flashed from install.wled.me, and is running WLED 0.14.0 (build 2310130)
Lil help?
What controller?
What power supply?
How is everything wired?
Fair questions.
let me start by adding more information collected from testing.
Crashing seems to happen most often (I assume its crashing) when quickly switching effects.
It also seems to happen pretty much every time when all lights are set to white, full brightness AND I try and save the preset. If I just leave them all on white full brightness, I can confirm everything works well. Its as soon as I try and save the preset, it crashes. It does also crash other times when just switching effects, so its not JUST saving presets that effect it. It also happens to much less complex wiring projects as well, with less LEDS. (One is getting power directly from the ESP8266 via the Vin line (USB powered.) Has power limit set to 850 MA) and it will crash on occasion.)
ESP8266 controller.
5V 40A PSU (Yes, 40 amps. Will eventually power many controllers and LEDs so it was bought specifically for this.)
Wiring has been 3x checked, but power wires may be between 20 and 25’ long (18 guage). All power to the controller (NOT the LEDs) is connected with thin wires and dupont connectors (I think thats what they are called.) Power lines run from the PSU, 20-25 feet to a WAGO style connector. 18 guage wires connect it to the lights (48 leds at this point), and then the dupont wires go between the controller and the WAGO connectors. A thin wire is connected between correct data pin on the controller (dupont connector), and soldered to the LED strip…
Now, it gets interesting here… (This is likely NOT the problem, as other lights with very simple wiring do the same, even those directly connected to the 8266. I only mention this to be complete and through) The Data out on the other end of the LED strip is wired, through a series of connections, through another 18 Gauge wire about 8 feet long to a second strip of LEDs that is connected the same way as these ones are to power. (Another 48 leds)
I hope that was clear. I will restate the wiring in another wording here to be sure its clear and understandable.
40 amp PSU runs about 25 Feet of 18 guage wire. Twice along that line are WAGO connectors, that connect 18 Guage wire to the LED strips, 48 LEDs each. The data out of one strip is connected to the data in of the other strip with about 6’ of wire. The controller is connected with cut dupont wires/connectors to the WAGO connections for power, and the Data in line of the first LED strip.
If you are having this issue with more than 1 unit and each are using dupont wires to the Esp I would remove those and either get a break out board with screw terminals or solder some decent wires to the pins. Those dupont wires generally make really poor connections. They are also very thin and could be getting starved of power if your strips pull a bunch of power fast (like when switching fx) and causing your Esp to brown out. I would also think that those thin dupont wires would have a hard time making good connection in a wago that is designed for much larger wires.
Side note: I would hope that you are using fuses with that 40A power supply, because there is no way that 18AWG wire can support 40A if for some reason it tried to pull that kind of power (short circuit etc…)
Breakout board will just take up more room, and I am trying to minimize the space I take up. But I will try and just desolder the pins, and solder 18 gauge directly to it.
Although I am not at all an electronics guy, if a brownout is what is causing this, and remains after soldering directly, any reason you can think not to use a capacitor to help with that? And if so what rating would you suggest?
And thank you for the side note. I am aware I shouldn’t run any more then 14A through those wires, and have fuses rated at 15A on the lines. The reason I have a 40A PSU is I will be running additional LEDs off of the PSU, and will be running different lines for them. Mind you the only reason I did add the fuses is because WLED did give me a warning when I set it to 40,000 MA. I would not have even thought about it otherwise.
I will get to the soldering in the next day or two (I hope) and hopefully don’t screw up the ESP while doing this (I don’t have the greatest soldering skills, but I do have more OTW from China) and will report back either way to let you know what happens.
If you’re soldering directly to the ESP board, there’s no reason to use 18AWG wire.
Stranded 20AWG or 22AWG is plenty for the power reqt’s of the MCU (well less than 1A normally).
They’ll also be much easier to work with and keep things flexible.
As far as brownout issues, the best way to prevent that is reliable power wiring to a reliable power supply.
A capacitor is a kludge fix at best for an improperly designed power setup.
If your main 40A supply is too far/too noisy/too (fill in blank), use a dedicated 5V 2A supply just for the MCU and connect data and ground from the MCU to to the strip.
That way you use heavier power wiring where you need it (the LEDs) and lighter, manageable wiring where you don’t (the MCU).
You don’t need to desolder the pins. You can solder your wire to the pins.
If you would rather test for a possible power issues before making changes, you could do like divsys said and connect a small 5v power supply to the Esp and remove the positive connection from your big power supply. Even like a cell phone charger connected to the micro USB would work. If your reset issue goes away then you know you are having some sort of power issue. But really in the end it is still best to avoid the dupont wires. They are just so small to be considered reliable.
If you do decide to desolder the pins, the easy way would be to cut between the pins of the pin header with wire cutters so that they are no longer a long strip of pins. It is much easier to remove 1 pin than a string of them w/out having a hot air gun.
So, I connected the ESP to a cell phone battery backup, and it seems as though the issue went away. So it is obviously a power issue.
Noisy power would make sense. It is a cheap PSU I got off aliexpress.
The issue I have with “Use a separate power supply for the MCU” is I already have had to run wires 20 feet though a mess of places. So it is quite impractical to run more wires. You said that a cap would be a kludge fix, but I don’t know if I can think of any better solution, but I am open to suggestions. I should also ask if several “splices” in the wire (via these WAGO connectors) could cause this issue? There are not a lot, but a few places it would be possible to solder them. But would be difficult. I don’t want to just do it to try unless someone thinks it may make a difference.
The final thing I should note. After soldering the power directly to the board (Still WAGO connectors to connect everything) the ONLY time this seems to happen is when the lights are on high (100%), and pretty much 100% power useage (Set to white) AND I save a preset… It will run fine at 100% for as long as I have tested, without crashing. However when it “crashes” doing this, its not recoverable without a reboot. It doesn’t coem back and reset.
What you’re describing is classic power issues to the MCU.
Multiple splice points are always a risk for noisy/poor connections.
If you go with the separate supply (I’d suggest that’s the best solution) the extra wires you need to run are not the same power wires you already have. You can use much smaller 22AWG or 24AWG cable.
That often makes it much easier to route your cable.
I like 22/4 alarm wire or a single pair out of a Cat5 cable can work.
Remember to include a ground wire alongside the data wire from the MCU to the strip.
Yep, it is a power issue. However it is one I ma a bit confused about… So I may need some help.
Voltage at source. 5.01v. Voltage at destination 4.99v No load. 25’ run, 4 splices… Seems not too bad. HOWEVER!!:
With JUST the esp connected… Voltage at source, 5.01v (AWESOME!) Voltage at destination, 4.72v… WTF? How is this possible? And what/where do I need to look to resolve it?
So I figure I should add, that this essentially means it is not possible for me to get 5V, that will stay at 5V to the destination, to my understanding. Even if I run a fresh line, at 5V, it will be 5V until the ESP is connected to it, at which time the voltage will drop to 4.7ish.
The only factor that I can see that make sense, is the distance of the run. That it is impossible to run 5V over 25’, put it under load, and have it remain at 5v, with the 18 gauge wire I have. So either I have a very incorrect understanding, or there is something really funky going on, and will need help to understand it so I can correct it.
With a current of 1A with 18AWG wire with a length of 25ft 4.7v seems to be a correct amount of voltage drop. Your ESP is likely using less then 1A, but with those splices that may account for a bit more voltage drop so the 4.7v result still seems plausible.
As a band-aid solution you could add a cap by the controller (maybe 1000uF) Not the best solution, but if it satisfies your needs you don’t have anything to lose by trying it.
The only true solution to voltage drop over distance is larger wire, or larger voltage and using buck converters to drop it to the required voltage at the strip. I feel that using the converters is a poor solution as it adds another failure point to the setup.
As Jinx mentioned, you can get a good idea of the voltage drop over 25 feet with 18AWG wire at 1A current by plugging the values into the KB Voltage Drop Calculator
Lo and behold you’ll get a drop of ~0.3V, exactly what you saw.
Now there are 2 issues at play here:
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If you draw 1A through 25’ of 18AWG, you’ll get a drop of 0.3V. The wire doesn’t care if that current is used by the MCU or the LEDs, same drop. Draw twice that current (2A) and you’ll get twice the drop → 0.6V. This is basic Ohm’s Law, the only way to reduce the drop is to reduce the current in the wire, reduce the length, or go to a bigger wire size.
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The MCU is going to brownout at something less than 4.7V. Once you start increasing the LED brightness, you’re going to increase the current you need and the voltage drop => brownout. You can either get bigger wire or put the MCU closer to the PS so the current it needs is going through a much shorter wire and subject to less drop.
The voltage drop effect doesn’t apply to the data line from the MCU to the strip as the current required for data is less than 1mA. This means your data line can be smaller and longer without worrying about voltage drop. You do need to be aware of picking up noise on the data line, which is part of why I suggest running a ground and data pair from the MCU to the strip.
So I am thinking the only way I am going to be able to do this is with buck converters. On a quick google, they seem cheap, but I have a few questions (And if this is not the place for them, feel free to tell me so and I will ask elsewhere)
The PSU I use does have an adjustment, and in videos I have seen it has been able to up the voltage to over 12V. I will test when I get home to see what I can get out of it.
So in regards to the buck converters.
On a really quick search, this is what I found:
hAliexpress link
That was a big one…
So my 2 questions are. Is there an amp limit on these things? I ask because I can’t seem to find an amp limit on the page. Aliexpress is not known for providing everyone all the correct information.
And secondly what happens when its set? Does it get set to an output voltage, or does it get set to a power drop percentage?
E.G. I set it to “5V”, do I get 5v out, regardless if there is 12v, 10v, or 6v coming in? Or if I set it to 5V when 12V is coming in, if the voltage drops to 6V in (round number for simplification) does 2.5V come out?
Just before we jump into the buck-converter zone (an approach I’ve used on many larger setups), maybe we could step back and ask about your setup and where you see it going?
I haven’t seen a description of what you’re trying accomplish - this isn’t a critique, I’d just like to get an idea of the scope of the issue for your setup (and maybe its expansion in the future).
As far as the general use of Buck Converters (BCs):
-
Most BCs work in general just like PWM analog LED dimming. They take an input voltage and connect it to a capacitor and then turn that input off and on very rapidly with some circuitry to make sure the output voltage is what you want.
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There are specs on BCs that usually specify:
-Max input voltage
-Output voltage (either a range if adjustable or a fixed value)
-Efficiency in%, - the amount of used power that actually gets to the output
-Maximum output fluctation
-Max output current
In general output fluctuation is very reasonably on most devices (10% on 5V output is pretty high). Output current and efficiency will often determine your selection. The current will determine how many devices you need for your setup. Efficiency determines how hot they potentially get and more importantly how much extra power your input supply needs. If a BC is 85% efficient, that means 15% of the input power (Watts) is lost as heat and you need to up the main power supply to provide for that loss.
So as to your questions - there’s definitely a current limit on the converter. Ali is famous for glossing over (or simply not providing) those kinds of details. My experience has been to derate the maximum power you can reliably expect from the BC by up to a 1/3. A 3A device will usually be reliable at a continuous 2A and handle 3A peaks. So if your usage is for continuous 100% White, you need heftier devices. Some of it depends on what the environment will be for your setup. Outdoor requires IP67 rated BCs and we tend to end up with higher rated currents to supply longer runs.
The output voltage for the BC is definitely a “fixed” value. As long as the input stays a minimum above the required output (usually something like 2.5V), the output is stable. That’s what makes the “high voltage bus” concept work so well. You can live with voltage drops on the bus that would unacceptable for normal operation because the BC doesn’t care if the input is 24V or 14V, it still produces a stable 5V.
Nope I understand. If you understand the setup, its easier to make recommendations. But it is a bit messy, and likely won’t change. But here we go. lol…
So, as I had said, I have a 40A 5V PSU. The original plan (And maybe still is with the use of BC’s) is to run low voltage wires throughout the house to where I want to run the LEDs. 5V was chosen for several reasons. #1, I am cheap, and 5v things seemed to be cheaper. #2 5V is the same voltage for both the LEDs and the MCU. #3 I wasn’t expecting any really long runs of LEDs that I think would be affected enough to matter, especially with injecting at both ends. The plan of the system was to make it expandable (Hence the 40A PSU, and I only have 96 LED’s thus far.) I am a very “Lets just go by the seat of my pants” kinda guy when it comes to this. This is a hobby, rather than specific full scale installs. (I know, planning is better, but planning turns this from a hobby to work for me)
So, thus far I have the PSU in one room, and I have to run wires to 4 different places, each of which will have 48 LEDs. 2 are wired with one power line that “splices” at about to 20’ mark (where the first set of LEDs will go). The other two will be wired the same way, but the max length is expected to be 20’ with that one.
So far I have the 2 sets of 48 lights running off one one MCU; just use 2 segments (96 leds total). However it is also connected to my Home Assistant, and controlling the 2 segments seems to be not ideal. So I am thinking about giving each there own MCU.
Then I am planning on running some on a set of stairs. The wire run to there from where the PSU is will be about 10 feet. I haven’t done all the measuring so can’t say for sure, but I am expecting about 300 LEDs. I am guessing there will be 4-8 power injection points, but if I can somehow get away with just 2, I likely will do that. They will likely be running white 98% of the time, but they don’t need to be at 100% brightness. The plan is to use WLED to help determine the power needed to run there to determine what way to do it, and limit power accordingly.
So yea, I know this is a lot of “hodge podge” but that is basically the way I am planning to do it.
Now, I hope I have not scared you away too much, lol…
Now, back to those BC’s… Any reason I can’t run them in parallel? If I need 4 amps, can I use 2 2amp BCs, and just connect the input and outputs together?
Not sure of your layout, but would it not be easier to use more smaller power supplies closer to where the LEDs/controller(s) will be going? Maybe some sort of diy decorative box or something to hide them in?
I understand the wanting to do things as cheap as possible as I try to do the same. But for the sake of sanity and ease it may be worth a little more $ for a few smaller power supplies vs messing with buck convertors and all the long wiring.
Another thought depending on where the main power wires are running and if you have lot’s of space (attic/basement) You could run heavier wire most of the way and then step it down to smaller wire close to your controller/LED locations. A fairly cheap option for something like that can be 16AWG or even 12AWG outdoor extension cords. You could use the hot and common both as your positive and the ground as your negative. About a month ago I bought a 50ft 16AWG cord on Amazon for $12
OK if I get the general plan right, you’re looking to spread out a bunch of small(ish) LED projects with the idea of running them from 1 controller?
The heaviest potential load sounds like the stairs @300 LEDs => 100W worst case (that’s a pretty rough estimate and it’s likely over by a chunk). The other 3 spots are about 25W each worst case (?) so a 200W supply is fair for this layout. I’d spec a 300W 12V supply or even a 500W (the incremental price is very small) to have lots of head room.
Given your rough distances, I’d expect it will be easier to use multi GPIOs and extra data runs rather than try and daisy chain these together. You’ll definitely want an ESP32 based MCU. You may want to have a look at the Long Data Lines section of the KB. It might become relevant depending where the MCU is relative to the various strips. Certainly, some kind of levelshifter is prudent here.
As far as multiple BC’s on one strip - absolutely. I typically try and space mine throughout the strip rather than focus on the ends. That distributes the load much more evenly.
As far as multiple MCUs and HA integration, I don’t think that’s necessarily going to improve your control in the end. I do a little HA connection myself and my experience has been that you may be better of with a single MCU and bunch of presets that HA can trigger as necessary (that was my experience anyway).
From my POV, going the preset route lets you debug what was going on when HA tried to trigger something. I didn’t always trust that the HA integration was “clean” as far as accessing internal WLED segments, etc.
just my $0.02
The advantage of the “High Voltage Bus - BC” solution is the ability to use much smaller power wires and smaller currents over distance. A 25’ run of 18AWG will have a 2.5V drop at 8A (approx 100w, 12v). That’s a trivial problem to handle in a BC setup and it’s very much easier to work/install/splice 18AWG over all.
Anything you can do to reduce the current required in long(er) runs is worth the effort in my mind. That’s just a result of the physics of Ohm’s law.
I’ve got many setups with 200 to 800 LEDs per run using HV-BC solutions. More than 1/3 are outdoor setups that stay up year round and have given very little issue.
At the very least I think I would use 2 controllers. One for all the small areas and one for the stairs, Assuming that you want to do Fx like the staircase user mod. It seems like it would be much easier to manage what preset/playlist to call for the stairs to do their dance on their own controller, than managing what other segments to leave alone doing their own thing and what not when sharing a controller. I mean it’s doable either way, but for the small cost of an ESP it just seems much easier for the more complex stairs to be on their own.
Sorry, just re-read your post and noticed I misunderstood what you were asking about using multiple BCs.
The short answer is yes, as I said earlier you can use multiple BCs to handle the load on a strip.
The detail is you don’t put them in parallel, you add them as extra injection points along the strip. Wherever you place a BC for injection, it will supply half it’s power to the “left” of the injection point and half to the “right”. The total current it can handle will tell you how many LEDs you are supplying from that spot. Divide that into the total size of your strip and you’ll see how many BCs you need.
For indoor use I like the small board 5A 5V converters, like: Aliexpress BC
Those are rated for 3A continuous and can be heatsinked for more, but I prefer to simply install additional devices. You probably want 6-8 for your stairs and 1-2 for each of the smaller strips.
Note, those BCs can handle up to 30V input so you could move up to a 24V HV-bus and 1/2 the required current in the bus wire. I’ve done that for a number of my longer setups (250’+).