Question ESP32's wifi flaking out when a light strip turns on

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Andy

Andy

Controlled Chaos
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I have an ESP32 that is connected to some perfboard, with a bunch of the pins brought out to screw terminal blocks:
1668217688154.png

Right now, the only thing actually connected is the LED strip, which is about 30" long. I have the ESP32 programmed through ESPhome, and can control the light through Home Assistant. When I boot the ESP32, everything is fine. However, when I turn on the lights, it drops from wifi. Rebooting (which shuts off the lights) or unplugging the light strip from the terminal block reconnects wifi.

Anyone have any ideas what's causing that, or how to start troubleshooting?

My current thoughts are:
  • I surrounded the wifi antenna with copper, screws, and more copper. It might just be blocking the signal when the line is energized.
    • Counterpoint: it does it even when sitting next to the AP
  • The LED strip might be drawing too much power, since it's powered through the ESP (which is powered via USB) instead of dedicated power lines, and wifi shuts off
    • Counterpoint: I have another ESP32 powering a longer LED strip in the same manner without issue
  • I messed up my programming and it actually disconnects from wifi when turning the lights on
    • Counterpoint: it takes about 10 seconds to disconnect. Also, the logs don't show an issue
  • ...heat issues?
  • It's a defective device
 
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So moments after posting this, I took another look at the power supplies I've been hanging this thing off of. It turns out that my wall wart only puts out 800ma, and my desk puts out a full 2 amps. I suspect I've been doing two things:
  1. This was initially powered by the power supply on my desk, but then strapped to the bottom of my (metal-framed) desk. Between the perfboard and the desk, I was one step shy of building a faraday cage for it.
  2. When I moved it next to the AP for testing, I was using a crappy power supply and the voltage from the LEDs caused the wifi (or the whole ESP32?) to drop
Switching it to a better power supply and moving it out from under the desk fixed it.
 
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Sounds like you solved that issue! Anyone got any sources for addressable led strips in water resistant sleeves? Someday I want to replace the house’s christmas lights with addressables but I havent decided which way to go.

Amazon has some individual adressable rgb leds not on a strip but each has a tiny board behind it that has been encased in silicone. This would be slightly easier to replace bad bulbs in the future over a classic strip. On the other hand a strip can probably be found in a waterproof sleeve and would be easier to mount permanently such that it didnt look like I had Christmas lights up all year long.
 
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Eric said:
Sounds like you solved that issue! Anyone got any sources for addressable led strips in water resistant sleeves? Someday I want to replace the house’s christmas lights with addressables but I havent decided which way to go.

Amazon has some individual adressable rgb leds not on a strip but each has a tiny board behind it that has been encased in silicone. This would be slightly easier to replace bad bulbs in the future over a classic strip. On the other hand a strip can probably be found in a waterproof sleeve and would be easier to mount permanently such that it didnt look like I had Christmas lights up all year long.
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This is what I've been using:

They make a version that goes up to IP67 rating (allegedly), but I've only been using the unsleeved version. They took a bit of trial-and-error to get working with ESPhome, but they've been pretty bulletproof once I figured out the correct summoning spell.

The backing tape is garbage though, so you'll want to pick up a roll of some of that vinyl double-sided tape or something.

It might be kind of expensive buying the strips 16' at a time (plus the power supplies to drive it), so you might find a better bulk supplier. I feel like these are a predone commercial product if you're not wanting ESPhome integration.
 
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I saw them commercialized via www.jellyfishlighting.com but they seem to be asking $3k for a house system so in addition to preferring a DIY/open source solution it is way out of budget! Fortunately, I think I only need about 50-60’ to cover the entire front eves since my house is tiny.
 
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Oof, I had no idea. I was thinking it would be like those string lights that you can get from Costco for like 50 bucks.

That's good that you don't need that much coverage. I've always liked the idea of lights that you could just leave up, and addressable LEDs open up a lot of non-decoration possibilities (automated lighting in an area when someone steps out? Lighting your parking spot when you pull up/leave?).

When I was a kid, the local "Christmas lights are my entire personality" house laid Velcro along their house lines so they could just throw the strings up each year. I always thought that was brilliant, but now that I'm saying it out loud I suspect it'd take a ton of maintenance on its own.
 
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I do keep checking costco and the like for a commercial reel of them every winter but still no luck. They are probably waiting for me to do it before they carry a purpose built/easy to use/cheap commercial version 🤣

Thanks for the link! I am leaning towards those on the white pcb with plastic sleeves. Possibly mounted on the flat underside of the gutters/flashing with that 3M-red-forever-tape. I am thinking a meanwell enclosed power supply to aim for a single power supply for the entire string if possible but ill have research that one.
 
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Eric said:
I am thinking a meanwell enclosed power supply to aim for a single power supply for the entire string if possible but ill have research that one.
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I think that's the best plan, and it's what I'm gonna do when I build my printer cabinet, but check the documentation for power requirements--a lot of them recommend running power lines alongside the LEDs and injecting power every 10' or so. I'm just running one 6' long strip* through an ESP32's power pin, and can definitely see the colors fading towards the end of the strip.

* It's broken into 6 1' sections, so there's a lot of wire adding extra impedance in there too.


Eric said:
They are probably waiting for me to do it before they carry a purpose built/easy to use/cheap commercial version 🤣
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That's 100% what they're gonna do 😂
 
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Finally got the remaining LEDs wired up to this. I, uh, guess I won't be powering it from a phone charger after all 😳. I'm not sure if I should be more impressed that I got it to run over USB at all, or that I managed to run it without frying something.

PXL_20221130_061822969.jpg

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Real-time view of my ammeter's wiring
 
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Also, @Eric if you're looking for some real-world numbers on the power draw for these LED strips, that 66 watts up there is running 72" of LEDs (110 bulbs) at full-brightness/white. When I ran it at full red/green/blue, I was getting closer to 20 watts.

I'm not sure why this is drawing so much power; their "parameters" section on the listing shows .1 - .3 W/ LED, so half what I am getting. I suspect that I'm running it at a higher brightness than they were for their testing, but if anyone has any insight, I'd love to hear it.
 
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I found this article with had some suggestions on wiring large arrays but other than voltage drop from the wiring configuration I don't see why it would be using so much extra amperage. Does it have a long wire and are they all daisy chained?


This amazon listing seems to be missing some of the components (filtering caps) spark fun suggests for array of WS2812B for the benefit of the LEDs lifespan but I don't know if they would have any relation the high current being used.



Also have you confirmed the voltage and current meter on the PSU are reporting accurately? I would double check them with a multi-meter if you haven't done so yet.

Your sticker says you're not supposed to be to be testing this high of current. You're gonna void the warranty. ;)
 
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I'm not Daisy chaining them; it's just the one long strip with the power connected at the one end. I see the filtering cap they recommend, but I think that's just when coming directly off of a power supply--I would expect the ESP's pins to be properly filtered. Either way, I agree that it probably wouldn't change the power usage much.

That's a good point about using a multimeter to double check the voltage. I used one to tune the volt meter when I installed it, but never checked that it's reading amps properly.

I'm not worried about the warranty. The company that built this is known for being as rough on their products as I am 😁
 
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That’s extra strange for it being just a strip! I am not great with strips though, all of my LED experience was with running the individual emitters in series and the parallel configuration of the strips is new and confusing to me. I really struggled to get my kitchen light strips sorted out.

Is 4.5v the minimum you can light the strip with? I know lowering your voltage should lower the current but I think those LEDs are 4vdc minimum.
 
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Honestly, we're bumping up against the limit of my understanding too. I think that that's the expected voltage drop as the current climbs--it is from the 5V rail on the PSU, and it drops in pretty direct relation to the strips drawing more power. AFAIK, it should just continue to draw more amps as the number of bulbs (and their individual brightness) increases.

It's also possible that the voltage/amperage meter that I'm using isn't correct--like we talked about the other day, I haven't hooked my multimeter up to it after setting it up and ensuring that the voltage load was correct, so I should start there.
 
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So I finally got my kill-a-watt inline with this, and it's actually using about 25 watts at full brightness/white, which matches the 11-33 watts they're estimating for my strip. I'm not sure why I was getting such wild results on my ammeter, but that's something to figure out "later".

That said, good lawd do these things get bright and hot. While it's coiled up, it's too bright to look at. The lights didn't get concerningly hot in my test, but I also only ran them for a few minutes. I think the connector, on the other hand, does. I definitely need to do more testing and let them run for a while. I'd rather they melt down on my bench than after they're installed on my ceiling 😳
 
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One method I have used in the past is to stick them on or inside aluminum u-channel or aluminum bars from ace hardware. That can make for an easy, locally accessible, heatsink even if it's not super dense it's usually more than plenty for a strip.

Arctic silver make's a 2-part thermal epoxy that is permanent adhesive and that is what I use on high power LEDs to stick them to heatsinks. the adhesive they include might be okay on it's own but I usually see it start to unstick with time+heat,
 
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Oh interesting. I was going to print a lightshade so that it could hide better on the ceiling, but aluminum might be easier. I'll think on that one. The adhesive that came with these is a joke; it falls right off. The good news is that it comes off cleanly and you can use something else (like arctic silver, who I didn't know made epoxy).
 
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Yeah it was funny to me to see Arctic silver as a lifelong gamer I have always known about them but the we would never consider permanent adhesive with a cpu heatsink.
 
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