 The Great Search. The Great Search. Every single week where Lady Aida uses all of her powers of engineering to show you how to find all the cool things on digikey.com and Lady Aida, this week there was a forum post or the person who had a question. That's right. Do you want to show the forum post? Do you want to show the thing? What do you want to do? Yeah. Let's go to the forum post first. All right. Okay. And if you all ever have a desk of Lady Aida great search thing, post it up in the forums because that way we'll definitely see it, but you can also like, you know, put it in the chat. Okay. Thanks for the great timing. All right. So what is it this week? Okay. So Eric says, I've purchased many AFU sensor break up boards, can't resist them. And I recently bought three BME 280 sensor boards. The green LED on that board is so bright and beautiful. I want to order them for myself to use in my projects. Can you tell me what the part number is? I'm living in the Netherlands, back in the war from Farnal in Digikey. Digikey ships internationally and people love doing that. Oh my God. Every time you say Digikey, that's the secret word of the day. All right. This is like our spare phone. Weird. Okay. Sorry about that. Okay. So somebody wants to know about these green LEDs. So let's go to the overhead real fast and look at this green LED. Okay. So this LED, it's an 0603 LED. And it's our power indicator LED that we put on our modules to let you know that it's plugged in and powered. Really handy. You want to make sure that your power, your system is working. It's a great little visual indicator to make sure that it's plugged in. So just in some boards, like this one does not have a power LED a lot. Some of our boards do not. A lot of our feathers don't. So this LED is an 0603 LED and it's an ultra high brightness 0603 LED. And it's green. And so I picked those two things for a reason. One, human eyesight is most sensitive to green. Like green is blindingly bright to us compared to other colors. You're going to get a little bit more boost for the current, like for the amount of photons hitting your eye, you're going to get the most oomph out of green. Now, technically it's 550 nanometers. This is a 525 530 nanometer LED. And the reason I do that is because there's a couple different, like semiconductor physics techniques to make LEDs. You can like bond materials together to make that PN diode that's emitting light. And the red, yellow and yellow green LEDs use one, I think it's in-gan. And those I find you are not as bright as to the eyes than when you go with the green, the pure green or blue or white LEDs. And they use a different chemistry. And I find those to be like much brighter and clearer. And so, you know, normally on LEDs that like I will show a, hold on. I'm trying to find, I actually don't. Okay, so I have a metro. Let me show a metro LED. So if you look on here, these LEDs, now they're quite bright, but these are using red, yellow and yellow green. And you can see the difference in the yellow green versus the bright green. It is like, this is a 20 milliamp LED. And this one I'm driving at like 100 microamps or less. So I'm using much, much less power because it's a high brightness LED with that pure green output. It's going to be much brighter than these yellow green LEDs. And the side effect of that is that I use much less power, but it looks quite good despite it. But you're going to pay a little bit more. So that's why I used a pure green LED even though on many dev boards, I tend not to. I tend to use the red, yellow and yellow green LEDs on those. For the STEMQTs, I make them a little special or pure green. So let's go to Digikey and show how to find the pure green LED. So first I found this cool mental floss article about the brightest color that it is that our eyes can see and it's 555 nanometers and it's about a jacket. But yeah, green LEDs, you got to be careful because they can really blind people. You can also use blue LEDs, but I think blue LEDs are a little passe. So let's go to Digikey. And so let's search for an 0603 LED. So 0603 green. Well, let's not search for green. Let's search for 0603 LED. And we want a discrete LED. Again, there's kits, there's arrays, there's all sorts of stuff. But we want just individual LEDs. One thing to watch for is, you know, and I have been bit by this. There's 0603 metric and there's 0603 imperial. 99% of the time when somebody you're talking to is talking about 1206, 0805, 0603 LEDs, they mean imperial, which means in metric it's 1608. I know. It's like why did they do this? I thought we were not going to have two confusing measurement systems. But that's what it is. So let's pick 0603, whatever, 1608 metric. And then again, you can pick the wavelength peak, right? We wanted, we were talking about this. We want to pick, there's dominant and there's peak. I mean, you're going to pay if you want to have like specifically binned LEDs. But let's just go with, you know, between like 510 and like 560 or something. Why not? And then you're going to pick the Millicandella neck. Well, actually let's go with active. So we get rid of all the ones that are not that active. So the Millicandella rating. So, you know, Millicandella is just, you know, basically how bright is it? Now, unfortunately some LEDs are tested at 1mA or 5 or 10 or 20. So this is not going to be, you know, you can't always compare apples to apples if you're really specifically looking for a certain type of LED. But in this case, I'm just going to tell you to make the LED use a 10k resistor. So it's bright enough to be human visible, but uses very little power. Not being driven at the full 20mA. You'll want something like 500 Millicandella. So let's go to 400 and pick up to like about 900. Okay. I think it's actually a pretty good, but yeah, and you can see current tests. So this is a little bit of my pet peeve, which all the LEDs were always tested the same current, but they're not. Next up, remember I said, you know, there's different, you know, physics for the semiconductors used for the LEDs. They don't seem to have a way to search for that. However, I'll tell you that if you get something with three plus forward voltage, that'll get you the ones that are pure green as opposed to just plain green. So let's apply. And then lens type. So I don't like the dome top kinds. Let's see if there's a photo of one of them. I'll show you what I don't like. So these are the dome top. Some people really dig these. I don't. I don't know why. It kind of gives me the willies. I think they look better, not lit up and not on boards, but like this is a cool piece of technology. It's super cool. It looks cool. It's like one of the, it's like clothing sometimes. Like it always looks good. But let me take it home. You put it on. It looks good on the mannequin, but it's like later on it's like that totally does not look good on me. So let's go with the rectangle with flat top. And then I think we already picked active. Folks like the pure green LED trick. Pure green, pure green. Okay. And here we go. So we got a couple options. So as usual, you know, when we're looking at these jelly bean types, generic components, you know, resistors, LEDs, capacitors. Even some regulators or transistors, you're going to have a couple options. You know, they do vary a little bit. You know, if you look, you'll see some are 450 and some are 500, some are 750. They're all about the same size. Some are like 140 degrees, some are 120 degrees. I don't really care. Right? It's, this is not, you know, somewhere a little bit higher than the others. To me, this doesn't matter. Like for you, it might. I will say that if you're making something where there's an array of LEDs, like you're making a matrix of LEDs, you really want them to be matched. Like it has to be all one supplier. And it has to be the same. You know, all the, all the wheels have to be the same because they're real. You will notice the differences when you see them side by side. But if it's just for a power LED, like nobody's going to know this, in my opinion. So here's something interesting. So the top link here is actually from American Opto Plus. This is a marketplace product, which I guess is this, you know, it's, it's kind of like a little bit like eBay or Etsy. It's like you're, you're purchasing it through Digikey, but the product is actually shipped to you from someplace else. You're not going to get it next day. Like, you know, classic Digikey quickness. So if that's important to you, but it is a little cheaper to get them from these other places. So if you don't care about the, if you don't care about the speed, you know, marketplace will give you the most options. But let's say we don't want to have the marketplace options. So now, you know, it's, it's a matter of pricing so we can put in, you know, I want to buy at least a thousand. So show the pricing at a thousand. And, you know, basically you can get them for as little as eight cents. I kind of like this one because, again, it doesn't really matter, but they have a lot in stock, which I always like to see. The price is good, you know, eight cents apiece in quantity. And this one is like super, super bright, 720 millikendales. So it's so bright, you know, you might even be able to get away with a 20k choke resistor and still have it be very visible. But it's a hack, right? This is supposed to be like an illuminating LED, but I'm just like way, way, way, way under driving it. And they're happy to be one off of 3.3 volts when you do that because the forward voltage is at the beginning of that curve. It'll look great. So this is what I sent the purses what I recommend. So it's a cute little LED. I like that it only has five-week lead time. You can get them for about eight cents. And they come in reels and tape and all that good stuff. So you want to have a cute little LED? This one, I think, will do the job quite well. All right. And from the chat here, Scarce says, this is a great search, great search tonight, because I'm getting ready to build final build materials for some boards I'm working on and looking for some nice green LEDs. I've used yellow, green LEDs. So I definitely agree on the overall visual quality. It's more for me. It's a power thing. When you use the yellow, green LEDs, I find you just have to drive them a little bit. You have to drive them a little bit harder for the cheap ones. Whereas these pure greens, I find that you can get away with a lot less current and still have them be quite visible. So for me, look, I don't care that much about power for these breakout boards. But I don't want to draw 20 milliamps for no reason when I can draw 0.1 milliamps. Why use the power? That is a great search. All right, thank you.