Adding back light for my arduino drawer...

Should had an extra row...

@GyroGearloose reminds me of the good old Matrix franchise

Blinkenlights to make stuff lit are always nice :3 here I have something similar that I took out of some 4W LED bars as well, deployed as the bias lighting for my desk. The bars had some row of LED's in series that were stuffed against a heatsink, and it's fed with some sort of current-limiting supply that's set to 20mA.. for a single row it's some 70 volts if memory serves me right. The power supply modules are pretty small so I just put them in a project box behind a switch that toggles the AC input. There's a picture attached in case you want some inspiration for PC bias lighting :)

What I don't like however is the picture in the comment. The left strip is all over the place. And what's that bulging thing on the right? For interrupts in the LED strip (to position it better, make it shorter or whatever) you should really snip through it (there's lines where you can cut) and then solder wires to the nearby solder pads. Those can be bent more easily and tucked away.

@Condor I did better... Led Strips. Very Cheap, you can get one color, multi-color (RGB), with fade, blink, and stuff. And most already come with a USB jack. We can also cut whenever we want. So I used 1/3 of the strip and saved the rest since the LEDs are bright enough.

Also, have an RGB led strip to use as RGBs for my light projects.

They are all hiden, so no much worry to put all preety.

The thing on the left in a USB hub , connected to a USB switch (check those out, good to turn stuff on and off, for 1.5€)

I'll post some links to show what I'm talking about.

This is all clumbsy for now, but I really needed the lighting, to find out that one Arduino Nano disapeared...

@Condor What did happen to Arch?

LEd Strips: RGB Or White Or Warn White

https://aliexpress.com/item/...

USB switch:

https://aliexpress.com/item/...

Lanter 5V led, love these:

https://aliexpress.com/item/...

12v bars

https://aliexpress.com/item/...

USb tester, suposed to be from 4v to 20v

https://aliexpress.com/item/...

@-ANGRY-CLIENT- Arch is gone?

@GyroGearloose he is not using Arch as main os

@-ANGRY-CLIENT- OHhhh tought It was the user :D

Well... I went full Linux Mint... And... And... Back to WIndows.

It's not easy to move to linux after so many years in windows... Hit a few walls when I needed software only for windows, and missed my FarCrys and Fallouts :D

have my VM anyway, also LinuxCNC to test as VM, hope it works inside a VM

@GyroGearloose by "he" I actually meant @condor btw

@-ANGRY-CLIENT- Yep, I got that :D

@GyroGearloose LED strips are OK, but they aren't very reliable. Also these are pretty much LED strips as well, except that they also have a heatsink on the back.. which allows them to run at higher amounts of power - 25mA or so - or have a better longevity at 20mA (heat decreases LED lifespan). Also they can run directly off the mains, which is a huge plus considering that these 3 bars run at 12W where USB ports are limited at 2.5-5W. Also I don't have any spare USB ports anymore on my PC, and didn't want to make it dependent on the power status of my PC :/

@-ANGRY-CLIENT- I've lost count of how many times I've mentioned it yet, but this PC has an Intel+Nvidia hybrid which prevents me from running any Linux distribution on it. I hate it. Recently I've unfucked my Arch laptop which I use every now and then to get a decent terminal (unlike that conhost WSL garbage) but it's still having overheating issues due to bad cooling design from HP. This Acer machine on the other hand allows for a really nice resolution (4480x1080 if memory serves me right), runs super cool and barely makes any noise. So yeah.. hence why I'm usually using this as my workstation over my Arch laptop.

And after having bought a couple LED strips that run off of USB lines as well, I was quite dissatisfied with them actually. Yes they can use USB power (which is nice) and they run well.. but their designers just mindlessly put a resistor in series with each LED, which is terrible in terms of efficiency. I ended up not using them.

@Condor Yep... Noticed that, why not use 5V leds? Probably are more expensive.

Anyhow, I have 3 led strips for separated porpuses, one yellow for games and movies, one white above me for work and now the 3rd one as backlight when I'm looking for something specific.

Just need to buy a good 12v charger to use the led bars instead of strips :D

@GyroGearloose If only there were actually 5V LED's.. that'd make life so much easier. But just like diodes, LED's have a forward voltage drop. Now in diodes that's often 0.7V (ignoring Schottky's for now) but in LED's it depends on the color. Red LED's have something like 2V (just tested a red 3mm LED here, apparently 2.15V) whereas blue ones are closer to 3.2V. And even across batches there's a little bit of fluctuation. The only thing that they all have in common is that they don't really want much more than 20mA. But in order to achieve that current, each color LED wants a different voltage.

The idea behind putting a resistor in front of the LED is to have that resistor drop some voltage across it and limit the current (and dampen the effect of possible fluctuations on the supply for the LED) but it is inefficient. Voltage x current is watts (which is Ohm's Law) and the return path to ground must always be equal to the ground potential (usually 0V) which is Kirchoff's voltage Law. So if e.g. I want to power a red LED through a resistor, I'd be using Kirchoff's voltage law and Ohm's law.

E.g. our red LED has a forward voltage drop of 2.15V, and our supply is 5V. So our resistor will have to drop 2.85V. For a current of 20mA (or 0.02A) that results in a loss of 57mW (2.85*0.02*1000). Doesn't sound like a lot, but that's just one of them.. and the efficiency of this thing will be very low. On the input we have 5V 20mA which is 100mW. And our LED which is 2.15V 20mA will only be converting 43mW of power into light. So the LED driven through a resistor is only 43% efficient, which is garbage. Now do that for a bunch of LED's and you realize why I didn't like that resistor-driven design. Anything that isn't at least 80% efficient IMO sucks.

@Condor I see...

And your right... Searched and all 5V LEDs have a resistor together.

I've been studying the LEDs. I have a few small 3mm that need a 1.5kOhm resistor for 5V.

Tell me something, If I give 3V to a white led I still need a resistor? Thinking of a way to not use resistors...

I'll be doing a big Christmas garden crib for my mom... And will probably use lipo batteries to power it, so it shouldn't give much loss to last longer.

@GyroGearloose If you can feed an LED exactly the right voltage, you don't need a resistor. Keep in mind however that your ripple on the supply output needs to be very low (20mV ppk at most I'd say) and ensure that any spikes in the grid are taken care of within the supply and that they never reach your LED's.

One more thing that I wanted to mention yesterday but was too tired to, is that some channels *ahem, GreatScott!* mention that you should use a 1ohm resistor anyway.. which is bullshit. The dampening effect of the resistor decreases as the resistance goes down. So a 1ohm resistor isn't going to protect shit. Besides, even a wire can have a 1ohm resistance.. and that isn't going to protect anything either.

So yeah, you can power your LED's without a resistor if you're close to, or a volt or 2 (assuming a couple of them in series) below the LEDs' forward voltage. So 4 blue or white ones from a stable 12V supply, no problem. Just be sure to not have any spikes and that your ripple is low.

Regarding the LiPo batteries.. they're very good power sources but just like all batteries, on their own they have a wide variety of voltages.. fully charged they're 4.2 or 4.35V, while discharged they're usually only 2.7V or so, and the protection PCB should (and I can't stress this enough) cut off at that voltage. Going below 2.7V isn't safe. Ideally you'll want to use a charge-boost-protection circuit along with them, and prefer lithium cells that have a protection PCB of their own slapped up their butt. Usually such charge-boost-protection circuits will be providing 5V regulated output and about 1A of current.. so 5 watts of power. Not sure if there are any that boost up to 12V or other common voltages, but I'm sure there are.. and if not, there's definitely gotta be some designs floating around for that. Probably you don't want a USB output though.. too bulky. Just a micro USB input to charge the thing and some solder pads for the output into the circuit.

Well, Lights fell Off...

Plan B...

Btw my closet got new lights lol

@Condor Tell me something, I can multiply the Voltage of leds If I get some in serial?

Like 6 red LEDs in serial = 12V

Actually, gonna test it out in the practice... Maybe burn a few more LEDs...

@GyroGearloose LED's in series have a higher forward voltage, in fact it's exactly the combined forward voltage of all of them. That's why I'm feeding my LED bars here 70V, because that's when they all combined consume 20mA.

@Condor Nice... That solves one of my problems for a mood lamp for my mom.

Just waiting for the clock chips.

And some energy to actually do anything...

@Condor BTW GreatScott! is one of my FAV channels... but I can't learn right in English (can't memorize as in my native language) and there are almost no Tutorials in Portuguese.

Using Brazilian Tutorials because of that... Brazilian dialect is so far away from Portuguese that is hard to understand, but stil...

https://youtube.com/watch/...

@GyroGearloose Just started watching the video, and actually got quite surprised at how my own understanding of electronics coupled with the similarities between languages (I can translate the essence of the video in real-time even though I don't understand Portuguese) enables me to understand the essence of the video. It seems to be a basics video, and quite a good one at that. Not 100% sure, but yeah given my limited understanding of the language, I would recommend it!

@GyroGearloose By the way, given this: forget what I have said about that 70V LED circuit of mine. Anything over 50VDC is potentially deadly! I've recently tested this with sweaty fingertips connected to a 50V lab supply and felt an annoying tingle. Anything beyond that Is dangerous! So stick with no more than about 12V as you're learning. Those should be safe voltages and are what I started with as well.

@Condor yep... You shouldn't touch above 30v with bare hands :p that's why I'm sticking at maximum to 24v for any project.
I was actually surprised by that channel, the guy teaches as if for noobs and teenagers. And all any gadget you see there is a video on how to make it. Diy solar power, wind power, toys...
I'm really liking it and I can memorize the lessons wich is a bonus...