Hello, complete newbie here. As the title suggests, I have a problem when trying to power on a ws2812b led strip.
I'm using a breadboard power supply connected to a mobile power bank (Output: 5V 3A) The power supply works normally when powering a nano through the 5V pin
I tried to power a strip of ws2812b led (68 leds) with the same 5V bus. As soon as the ground and 5V pins of the strip gets plugged into the bus, the led on the power supply shuts off and so does everything powered by it. The data pin was not plugged into anything.
Upon further inspection with a multimeter, the seemingly off power supply was actually still providing less than 1V into the 5V bus.
When the pins to the led strip gets disconnected, everything returns to normal. Power supply lights up, nano boots up, etc.
Ah there, unfortunately you are somewhat mistaking that "breadboard power supply" for something useful.
Well, actually, it is useful - for powering small circuits - and I really mean small, built on a "solderless breadboard". It is actually quite a useful one. I have not seen this particular module before and suspect it is something of an "orphan" - I can find no Web reference to an "HW-832".
Note the component on the board labelled "JG". This is apparently a "polyswitch" - a resettable fuse. I would guess its rating at 500 mA. It is possible your LED strip is randomly attempting to draw more than 500 mA. On the other hand I am surprised it does not work and suspect you might just be connecting the 5 V and ground backwards.
Note that at full brightness, 68 WS2812 LEDs will draw about 3.75 Amps and your "breadboard power supply" most certainly will not cope with that. It sounds as if you are intending to use it simply as a means of connecting the micro-USB connector from your "mobile power bank". You may be better to use just a "micro-USB breakout".
You may note that most people here will advise you not to use "solderless breadboards" for currents beyond 1 Amp in any case; you really need to be able to solder your LED strip connections properly.
Thanks for the suggestion! I'll definitely check it out.
However as you suggested, I'm not sure about why the LEDs doesn't at least flicker or light up? Side note, without data input, do the LEDs light up at all? I am also very certain the 5V and GND pins are correctly connected. Puzzling.
That should work except you are over 3A with all LEDs at full-brightness, and white.
I'm not even sure what that is... The website says " Power test board module, power supply test circuit, 3.3/5v switchable voltage". ...What? I don't think you need it.
I never buy "cheap stuff" made by unknown manufacturers from AliExpresss or eBay or from 3rd-party Amazon sellers, etc. I like reliable suppliers who give you a link to the manufacturer's datasheet.
Well, it is generally perfectly functional as no doubt this "breadboard power supply" is and
generally exactly the same as from the "reliable suppliers". The "manufacturer's datasheet" including a schematic is by no means available even from them. For ICs, you generally expect it, but for complete modules, a bit of an "ask".
Consider how much of a "datasheet" you get for an appliance such as a video monitor. Sure, the resolution and what sort of inputs you can connect, but it is hardly going to tell you how it works.
Uhm, because they're not supplied the power to do so...? As pointed out, your power supply cannot source the current your led strips needs. How do you expect it to light up under that condition?
Not necessarily, so that's another possible reason why no flicker is observed. Nevertheless, the leds may turn on for a very brief period (a few microseconds) upon startup, which would not be visible, but it may very well be more than enough to force the power supply into shutdown mode. Moreover, the led strip may or may not contain one or more capacitors, which, when connected, will draw a substantial surge current.
It all still comes down to your trying to power a device with a power supply that doesn't have close to the capacity needed to power it. You can keep scratching your head about it for weeks, but the only way out of this is going to be replacing the power supply or reducing the load it sees.
Never never never connect up stuff with the power connected, it is one of the best ways of damaging stuff.
That means the load is drawing more current than the power supply can handle.
You and the power supply have a disagreement as to what it can supply. I will tell you what, the power supply is always right.
