 And we'll just Lady Aida. Hey everybody, it's me, Lady Aida, at my desk laxing Sunday evening that we would do a little bit of a stream just to see what's going on at my desk. I mean, there's a lot of routing actually. I see a really cool project. Yeah, this is the glasses. I fucking finished it. This project, this board took me like 12 hours to route. It was, and I'm a fast router. I route boards like, believe me, I'm doing it automatically, this took me 12 hours. I think so many breaks. But let's take a look at it. I can just show you, it's just kind of bonkers. How many things are in it. So it's got 136 LEDs. This is each of the 2 millimeter LEDs. And they're matrixed up. Of course, this board layout would have been a lot easier. If one, it wasn't two layer. And second, didn't have these cutouts in a weird shape. And three, I decided to go with something like dot stars or neopixels. But as we mentioned before in previous shows. Would it also be easier if you didn't have the looming fear of no chips for anything you make? Well, I already got all these parts. So I'm good. All right, well. When I got those chips and I have them stashed away. It can always be worse. I'm a yoink them. But to save the cost to make this affordable, I didn't use individual neopixel LEDs because 130 neopixel LEDs would have cost whatever, 130 times 10 cents a piece, 13 bucks. And so maybe even if I got it at a really great price, $10 just for the LEDs. And also there's some risk of them being damaged. Whereas these LEDs are a penny a piece. And so I can put 138 of them on a board with a chip. And even if I have some yield issues, it's not too bad, although I'm going to try to avoid yield issues. So anyways, this board is routed. I routed it 6x6 and the vias are 15 mil. I don't, 15 mil is as small as I get for vias. I know that people can, you know, you can get boards with smaller like 8 mil vias. But I find that 19, I've never had a problem with any board house I've used, prototype or production. 15, you know, 0.15 and a half, 15 mil. I did have problems with yield, PCB yield, with 15 mil PCBs when I ordered from PCB cart. But JLCPCB and advanced circuits and other places seem to be okay with it. So it depends on your board house. But the 6x6 mil rule, that's not the issue. It's actually vias are usually where I've had problems. Yo, what's up? Is it a two layer board to make it affordable? It's two layer, yeah. It's basically like you're better off doing almost everything before going to a four layer board. You know, I just kind of discovered that when I did the design for the circuit playground, Bluefruit, there's nothing wrong with four layer boards. Use four layer boards if you need them or eight or six, whatever. But unless you're doing something, and believe me, there's some boards like BGA boards where it's like, look, you need to go four layer because you cannot fan out this board. There's not enough room, there's no space. But if you're doing a board where you can, even if you go down to five mil rule, four mil rule, it'll still be cheaper than a four layer board. You can do so much to a two layer board before it becomes more expensive than just doing a plain four layer because the four layer process is usually outside of this lowest cost process that a board house does. And so, I don't even know that I have any four layer board designs that I've manufactured. I always, I really, I'll pretty much do anything before I go there. I really try to stick to two layer. And so far, I've been able to get away with it. So, there you go. We're not in the big pocket of the big four layer commission. A two layer commission. Sorry. No, the four layer, if we were in their big pocket, we would be promoting four layer boards, but we're not. There's nothing, I mean, look, believe me, there's boards that I've had other people make, you know, we sell their four layer and that's fine. But so we're out of this whole thing. It took forever, but it's done. And it's not, it's not, one thing that was actually quite nice about it is because it's a matrix, not a direct driven, like NeoPixel, is the traces can be thinner because you're not powering each LED separately. It's another thing, like dot stars and NeoPixels each have one milliamp quiescent current, which we're not gonna have here. There's no quiescent current because it's that, you know, the LED is only driven when it's driven. And there's no ground plane because it's not ground reference, it's matrix reference and everything is, you do need to have a good ground connection, but there isn't a, you don't need a plane behind it. And that's another reason I didn't need a four layer board. So this is up for prototype. So another thing is finally I was able to get the ESP32 S2 mini modules. It's the, the S2 modules that are not the rover style, they're the smaller modules. And they, I ordered these many, many, many months ago, but of course with silicon torches, you know, it took an extra four months to get them or whatever. They finally came in and so I'm like, yay, I can do my ESP32 S2 feather that I designed like six months ago. And then of course, something else happened, which is, well, one, you know, every other part on here is pretty much, there's a lot of jelly beans, capacitors, resistors, there's the battery charger chips, which have been a little annoying, but I did, I do have some of those. This is a BME280. I kind of like stuck a little sensor on there because I had room and I thought, oh, a BME280 does like temperature, humidity, barometric pressure, you know, it's all in one lovely little sensor. I thought we'd have a version that had this. But at this point, I can't even back order BME280s. They, they Bosch just is completely fell over in this silicon shortage. So, you know, I can chip the board without the sensor and just leave it unpopulated and that's fine. It's not necessary. But the, this sensor, the, this is a LC79203, which is a battery monitor chip. So, this chip is what's end of line a few months ago or, you know, six months ago, which was, you know, again, historically end of line chips don't matter. Like it's end of line, be like, ah, you know, there's a last time buy, and the last time buy is usually 18, 24 months away. You have a long time usually to order as much stock as you possibly need to put your last order in and you're done. They didn't do that this time. So, you know, it's, you know, when you're done, they didn't do that this time, right? Because of silicon shortage, there was no last time buy or at least I couldn't figure out how to do one. They're just like, we're done, it's over. You can't get this anymore, like no warning. And so it's really annoying. So, one, one thing I noticed is that, you know, if you go to Digikey and you go to LC79203, first off, there's a couple of variations of this chip. I do like it. It's a very inexpensive but very easy to use chip and it comes in a nice TDFN package. It got discontinued and it was replaced with the LC7092, I think it's 204. So they basically, you know, discontinued and replaced it and the board they replaced, the chip they replaced it with is a 0.4 millimeter BGA. And I really, really, really don't want a 0.4 millimeter BGA in my feather design because I'd want something easy to fab and again, does not require a four layer board. And once you get to 0.4 millimeter pitch BGA, you start needing a four layer board. Do not want, but I really like this chip. So the good news is that while this version was not available, this version, the 0.5 millimeter BGA is and the middle pan of the BGA is not, you don't need to fan it out. It is, it's, they designed it in a way that doesn't suck where it's at nine pin BGA but only eight pins are really needed and the middle pin is a ground pin and so you can connect that through to another ground pin and you're good to go. So, you know, we had a, you know, a breakout for this chip, the TDFN version. And I'm like, all right, well time to, you know, make the BGA version. So we spun this board and now it has this 0.5 millimeter pitch BGA, which I think will be all right. I made the holes a little bit bigger and I think there's no reason our pick and place can't fab it. I think it'll pick and place it. Okay, a couple of people reporting chip shortages, stuff getting held up in Shenzhen. And next question, any concerns with the temperature sensor close to the ESP32 S2 module? No, and check out a previous video where we go over that. It's fine. We took previous desk radiator. Okay, so, you know, this one, I gotta, you know, I gotta change this package now, hold on, update the library and then I'll change the package over and now it's much smaller and cuter, but it's the same chip. And so I'm not worried about like, you know, so I didn't know this chip, I tested, I did the power monitoring, you know, management of it and all that good stuff. So I know this chip is good to go. So, you know, I'm going to reroute this board with this new little mini chip, but, you know, long term, it's not sustainable. I can't rely on this because even though there's, you know, 16,000 of these in stock, it's still end of line and it's still, you know, there is no last time buy and there may not be. So I think I'm willing to risk getting this design out the door, but I do need something, a long term solution or an alternative solution to having a battery monitor. And the reason I have the battery monitor chip on here and not just a resistor divider is I really wanted to have a higher quality battery monitoring solution because I think people want that for like an ESP32 based thing, but without the continuous current draw of a resistor divider and also maybe something that does a state of charge. So it converts the voltage because you know, ESP32s, they have, they have a weird kind of non-linear ADC, something that pops out like, oh, your battery's at 30% or 50% or whatever, I thought would be more useful for people than just a resistor divider. So, let's, do you have any other questions before we get into the great search? Go ahead. Yep, let's do the great search. Okay, great. Where? The great search brought to you by Digikey and H. Everything you did, Digikey, Lydia uses her powers of searching and finding, especially in the middle of this drought, this chip drought, to show you how to find what you're looking for. Lydia, what is the great search this week? Okay, the great search is actually what I did today. So, some Sundays I'm like, what am I gonna do for the great search? And then today I was like, oh man, I gotta find an alternative for this part that I can't get, that I can't get and the alternative I can't get and before you know it, you're like four layers down. That sounds exactly like great search. That's the great search, that's where we're at. So, for this design, this design for this feather, I used the LC 7903 battered monitor chip. The TDFN version is no longer available. It went to end of line. There was no last time buy because of silicon shortage. And so I kind of got like the rug pulled out under me. That's a good idiom, rug pulled out under you. We're collecting idioms and stuck without an alternative. There is the, we covered, okay, we can always get alternative packages sometimes and there is an alternative package for this chip, the BGA package. And I can use that BGA package temporarily basically for a few months, but it will also run out, it's end of line. So I want to find an alternative lithium ion single cell battery monitor, something that has an ADC, communicates over I-squared C and doesn't use a lot of power so that it can stick this on, it does the battery monitoring, cool them counting, state of charge calculations for you while still letting the main processor go into deep sleep. And when it wakes up, I can always ask the chip, what's the state? And of course I want it to be inexpensive, I want it to be easy to use and I want it to be a package that I can put on a two layer board. So I thought that's what we would do. All right, let's do it. Okay, so let's go to the computer. Okay, so this is the previous package, the chip that I was going to use, the TDFN chip, and then I can swap that for the BGA package and this will again, I can kind of limp along with this for a few months because I can get some of these, but eventually those will run out and this is the life we're living. So the chip that I was using before was basically this one. You know, this is no longer manufactured. It says some substitutes, you know, it has some substitutes, but we're gonna do our great search substitution work. So what I want is a battery monitor. I want to do one lithium ion thing, I squared C and surface mount, although you know they're all gonna be surface mount and let's see what we've got for similar devices. I'm not gonna say normally stocking or in stocking, I want to say no marketplace just because it's a little confusing, I want to just, I'm kind of in the specification stage so it's like I don't really care whether it's in stock right now, as long as I can get it in a few months. And I want to look at prices in the 5,000 piece range or so. And you know, as you can see there, this is the chip that I historically liked, you know, these are the two versions, they're the least expensive at about 70 cents a piece. The BGA version and the LC709 TDFN version, but you know, not this one, not available, this one I can use until they run out of stock. So let's go down the list. Ooh, the BQ27426, okay, this looks pretty good. Is that the one? What? Is that the one? No. Well, no, not only is it not in stock, but if I ask it, when's it gonna be in stock? It says April 2022. Okay, so it's not only are we trying to find a part, but I'm like, I really want a part I can get, you know, like this year maybe, you know, would that be so hard? Maybe get it in the next like three months. We were spoiled when we were, we were babies buying parts that were in stock. This family's, you know, it is quite a nice family of chips, but yeah, basically, you know, all of them are April 2022. This is the same part of that family. This one, I think is also, you know, September 2022, like not even within the next year, I'm gonna be able to get this part. So I basically kind of went down this entire list. And until I, and then this one was okay, but I really didn't want a BGA. Again, I want something that's a two layer board. I don't want something that's BGA with middle pads because I really don't want something that's gonna be a pain to route. So what I did find, you know, I basically like scanned through this. Almost all of these are completely unavailable anytime soon, except for this one, the Mac 17 048. And this one not only has 3000 in stock, but it has 9000 in the factory. It's not inexpensive, but it is TDFN. I can get it, you know, quickly. Another thing you can do is of course, you can put down, you know, even more. And you can see like, well, there's gonna, you know, if I need 30,000, I'm not gonna get them till 2022, but there are gonna be two more shipments of 10,000 a piece. So in October, so you know, if this is something I want to book for nearby delivery, you know, I have a shop, but again, it isn't stock. I'm not gonna need more than 10,000. I just kind of know that that's 10,000 a year is about how many, you know, that's how many I'm gonna need for now. So I think that, you know, this is kind of what I'm thinking of going with. So I designed a, I did a, you know, a board package for it and laid out the package. And then I designed a breakout for it. So, you know, this is what I start with whenever I want to design. I basically pulled out the LC79203 and I put this in. One nice thing about this chip is it doesn't have some of the BQ chips, the TI chips used Coulomb counting when they had the basically resistor between the input and output. And one thing that is kind of nice about this Mac17 chip is like the OnSemi LC709203, it doesn't have a resistor. It actually looks at the voltage, the historical measurement of the voltage to track what the state of charge is. And, you know, I kind of like that. I think it's nice because it doesn't matter, you know, especially for a breakout board where people can accidentally connect the wrong way. This is a kind of an elegant method of measuring because you don't have to worry about having it backwards and you don't have to worry about the resistance, you know, being in the way of your boost converter or something or affecting something down the line. So I'm gonna start with this. I normally actually would have gone for the BQ chips. The BQ chips were quite nice. They were much less expensive and they had I squared C and they had, you know, also either voltage or built in Coulomb counting capability. But if I can't get it in the next, you know, six to 12 months, even if that's as soon as I can get it, I'm gonna start actually designing with parts that are more expensive just so I can get something out the door and then reevaluate in a year. It's easy to then, you know, I can always reduce the cost later by subbing out the old part, but not being able to ship something costs money every single day. So yeah, these are the design trade-offs I'm currently making is going with parts I normally wouldn't go with just because I can get them knowing that I'll probably have to do a redesign down the line, but you know, I'll deal with that later. You know, I'll say, hey, I redesigned this for a cheaper chip and here is a new driver and here's the differences. And I've done that before. We've designed a lot of our feather boards or early Metro boards, whatever, with FTDI chips. And then when we could get SILabs USB serial converters, which I like a little bit more than the FTDI ones, they're less expensive and they have a couple capabilities that I like, very high speed, you know, data transfer and stuff. I redesigned a lot of boards and said, okay, I used to use the FTDI chip now using the SILabs chip. Well, the SILabs chip is also end of line. So maybe we'll do a future show where I show how to swap out a SILabs 2104 as well. Yay, it's like juggling. All right. And that's the great search. Where? All right, and I had one question here. How do you validate newly created libraries, spin a PCB with just a component or test it with some prototype design? I don't think I'd make a breakout like this, but you know, I've really learned, I'm not saying my packages are perfect, but I've really, I've made almost every mistake at this point. And so I'm actually pretty good. When I make a package, I usually don't, I usually don't mess them up. I know that's like a weird thing to say that's just gonna jinx me because I'm gonna mess up my next package. Another thing is from Digikey, they do have a, they often have a CAD file download where you can download, so you go to the computer real fast. At the bottom here, they have Snap EDA, which you have to make an account, but it is free. You can download the footprint and symbol. And they do this, this is a service that the companies work together and they pay them to make it in the format. Then you can then download in various Altium or Kacad or Circuit Studio or DesignSpark, whatever. You know, it's not forever guaranteed. Oh, that's kinda nice. It's a little mouse over there. But so far, I've had very good luck with these. I just personally sometimes like to make my own packages, but I've used these and had great success with them as well. All right, we'll see everybody during the week, full week of shows ahead. Please take good care of yourselves. Lots of stuff's going on. Stay tuned to The Aid for Love. Social media places and more, and we'll be back for just go lady it next week Sunday. Thanks everybody. Have a great week. Bye, bye.