 And welcome to Lady Aida. Hey, everybody, and welcome to my desk. It's me, Lady Aida. Mr. Lady Aida is on camera control behind the seeds and in the chest. I'm gonna be Hermes Eve, blasting some stuff off to the moon tomorrow. Oh yeah, that's cool. Yep. Okay, cool. So this weekend, I was, we went out for some nice long walks and I came back and I just jammed out on a bunch of boards that have been waiting for parts over the last two years. I don't know if you knew, but there's this part shortage, which means I would sometimes get samples, design a breakout board or a dev board or whatever, and then be like stuck waiting for like six, nine months, year, 73 weeks until the parts appeared. And so there's a couple of parts that showed up and also just some boards that I've been meaning to get out. And I thought I would just show a kind of a little STEM a Sunday. Yeah. What do you wanna show first? Wanna go to overhead? Yeah, let's go to the overhead and I'll show the first board. So as we talked about last week, the CCS-811V, which is a very popular gas, total volcanic, total volcanic, volatile organic compound, not volcanic, volatile organic and CO, effective CO2 sensor. A lot of people really liked the CCS-811. I personally think the SGP-30 and 40 have been really good alternatives, but CyroSense did come up with another chip. And this one's interesting, the ENS-160, which we chatted about last week. It has four gas sensors that are slightly differently doped and then it takes the data and it does the merging for you. So one thing that's nice about the sensor compared to like the Zmod and the Zmod chip and the BME-688 series is that the ENS-160 does all that calculation for you like the firmware is already loaded on the chip and so you don't have to like link this binary blob with like weird licensing stuff going on. So the ENS-160, and then if we go to the computer, CyroSense actually wrote an Arduino library. This is a kind of, you know, I know this is like no longer new, it's been a couple of years, but I'm always kind of shocked now that sensor companies are actually publishing Arduino libraries and like they're like pretty good libraries too. They work pretty well. So this library, what's funny is I was telling Phil about this, somebody was like, hey, I want a circuit Python and micro Python driver and it's like, you know, because I wrote the driver and I was looking through the issues and I was like, yeah, I just wrote one. So check it out. And they just replied with a little thumbs up. But so I wrote a library for this in circuit Python Python yesterday and it's the code's working. And it's not a bad sensor. Like you can set the temperature and humidity and then it basically does the data calculation and spits out air quality index, TVOCE in effective CO2. And then you can also get the raw resistances, which I thought was kind of neat. Like they do the math for you to tell you, you know, sort of what it equals out as effective CO2 or as air quality or like, you know, organic compounds, but you could also just get those resistances if you want to plot them. And so this little driver I wrote, so I've got it going on here. You can see, maybe I'll make this text a little bit bigger. And then I've got this Clorox wipe. You know, this is a very handy thing for testing organic compound sensors. So I put it over there and you see the TVOCE starts going up. It's like, you know, it doesn't go up immediately, but it started with like 40 and that's already at 200. So just holding this nearby, right on top, because you don't want to like poison the sensor by having alcohol directly on it, but just wafting it nearby is a great way to test that this sensor is effective. Usually I would use some scotch, but you know, post COVID we have a lot of Clorox wipes. Let's scotch more Clorox. We drank all the scotch. So this one sensor that I wrapped up and I got the tester going for it. One thing that's interesting is the sensor has both I squared C and SPI interfaces, but like CYOSets didn't even write the driver for SPI. So we kind of only focused on I squared C. So that's sensor number one. Okay, next up, whoops, just don't plug it. Okay, so then let's go back to the overhead again. I'll show two more completions. So we chatted about last week the LTR329 LTR330. So again, they both have the same footprints as different boards. So I ended up just taking different PCBs and just soldering that, you know, just to get it going, just soldered the chip on there. So the LTR3R3, I recycled an LTR390 board. And one of the things I really like about STEMI QT standardization, I know there's some people who are like, ah, I designed a board that used your old sensor. You know, you kind of just did whatever size and now there's this new sizing. It's great to have a standard, but not only is it handy for people who are doing mounting because you can kind of easily swap boards in and out because the mounting holes are almost always in the same spot, but it makes tester design a lot easier. So these are two testers and these are actually generic testers. So you see here, they'll just say, you know, five pin STEMI QT and then this one is generic six pin STEMI QT. So one of the things that I also have to, you know, spend a lot of time on is designing tester PCBs. But if I can just design some generic ones like these for, you know, the standard power ground clock data, power ground clock data int, you know, I can, it just saves me a lot of time because I can reuse testers, I can reprogram them and these are all plugged into an Arduino Uno. I just removed the Arduino because I'm doing different testers right now, but they just plugged into our Arduino. So like this simplicity and modularity of sensors is really working out for me. And then, you know, we have a buzzer and LED and it just makes the testing procedure and the designing of the testers like super stress-free because I can take an old tester, put this board on there, write the code, and then I don't have to like design a new board, which is, you know, always takes time. Okay, so that got done. You can see it really is a STEMI Sunday. Next thing is we had someone request this. It's a STEMI QT hub. And Mr. Lady, you recommended having it kind of point up so you can mount it and you don't have stuff sticking out. So this just has five vertical STEMI QT ports and they're all tied together. So I can just take this one and say plug it into, I'm sorry, I can take, you know, I've got my FT232 board. Let me make sure I got this lined up. I plug this in and boom, you know, they all light up and they're all powered and they all share the same data and clock lines and power lines is very convenient. And then they also breakouts for the, you know, in case you want to breadboard this as well. So handy if you want to, you know, almost all of our boards are chainable. You know, there's a port on the other side so you can always chain them. But I did see someone who was like, yeah, like for the design I've got, it really wants to be a star shape. And I was like, you know what, you know, for a couple bucks, why not have this port? We also stock this version from SparkFun, which is good too. I wanted something that was in kind of the standard sizing that I use, you know, I try to keep all of our boards as much as possible into this, you know, 0.7 by one inch sizing, you know, getting the mounting holes always in the same spot. And so I think between the two of these, you know, there's a lot of hubby options. What do you think? Sounds cool. Okay. Moving on along. Okay, I got a bunch of other stuff. Okay, so then I also got this Stem and QT shifter board that I'm wrapping up. So this is, if you have a five volt board and you want to convert it to three volt logic. So this would be, you know, it's inexpensive because of course there's no sensor. There's just a regulator and a level shifter. So this is handy when, you know, there are some boards that are five volt or you want to, you know, plug this in and wire it and have Stem and QT, but you also want like a regulator and shifter. You know, there's a lot of times that I'm connecting up. You know, I do really still like to write my code for the Arduino Uno, which is five volts. It's, you know, it's a very standardized way. I know if it works on that, it should work on everything. Because it's kind of the original official Arduino. And that's five volt power and logic. So this is a little accessory helper. You plug into the breadboard or you plug in here and then it gives you five volt power and regulated output and then level shifted data. Okay, cool. And then, so today's Stem and QT board that I'm going to be working on, I just put it together. This prototype is the DS4420. So yeah, again, I designed this in 2001 and I just couldn't, I couldn't make the board for like a year. And then there was some parts on Digikey which I bought before the show because I've learned my lesson. Don't show off a cool part before I've ordered what I need. So I booked up the pieces. So this is a, it's interesting. It's a, it's an analog headphone amp. It takes line level in, gives you headphone output but then there's also I squared C volume control. And, you know, it's not a very complicated chip. It only has like literally one register and it's like, you can set it, there's like a seven bit volume control so you can, you know, low and high. I don't even think it does balance or, you know, bass treble, it's really just volume but you know, that said, it's probably still handy. You know, I saw JP was working on a bunch of audio projects where like having digital volume control could be handy. Not having a digital, a digital potentiometer can do it but you know, of course you want to have a, this is more repeatable. It's got a lot, it's got logarithmic control already. It's by DB not by voltage divider per cent. So you don't have to worry about getting a log pot and of course it also does amplification for you. So I just got this and I just like basically verified that I squared C scans correctly and so that's good. I'm going to work on the driver for this, although again, a very simple board, like only one register but you know, after having written a bunch of drivers for like the ENS 160 and the LTR light sensors, all of whom were like, they had, they didn't have infinite registers but they had a lot of registers and just making sure that we have the setters and getters for every bit was a little bit of a pain. So that's that. And then do you have questions? Otherwise I can show off some samples. Yeah, show off the samples. Okay, well GP requested some new colors of the silicone wires. So we have these really nice silicone wires. They're really durable and thick and they've got like the premium ends on them. And we had I think like red, black, yellow, blue and something and he's like, well, I want more colors. So these are the like the remaining colors, purple, green, whites and orange. And I just got a sample of the silicone colors but they're silicone, they feel good. They're squishy. And so I'll try these out. I just got these yesterday. Go back in the little tubing. And then I've seen these magnetic cables before these Vanguard USB cables and they've always been kind of like somewhat mediocre but they finally got pretty good. So this is a USB A cable. And then it goes to these, you get different magnetic tips. And again, these were not super great before but they've gotten a lot better. So this is like lightning and then USB type C, cute. And then micro B. So the idea here is that you would actually, you know, you would have this maybe plug into your board like permanently or not permanently but semi-permanently and then you could connect and disconnect it. So this would be maybe a way to like, you know, people want to have like different debt boards and you just plug in whatever you need, whatever and you don't have plugging and unplugging and unplugging and then if you have like a micro B board, let me see if I have one right here. Yeah, like this clue, these are quite magnetic. Yeah, so this is the clue board and then you plug in either way and what's interesting is these are bidirectional. I guess I should plug it in and see what happens. Hopefully it doesn't catch on fire. Always fun testing samples. You never know what's gonna happen. Okay, so let me plug this in. I have a little extension cord. Okay, so then, oh, it's nice. It has a little green LED and then, yeah, it looks like this popped up, okay, cool. And then I can also plug it into here and then this popped up as well. I do like that green LED, that's kind of nice. What do you think? Yeah. All right, cool, it's a good sample and I like this as like a woven. It's a nice woven cable. So, you know, it's a little bit more expensive to get the nice stuff, but anything that I personally use, you know, I'll probably use this cable because it'll be nice instead of like, you know, instead of having like all these cables I need one of every tip, I'll just have the tips into all the dev boards I use all the time and I'll just break it and make the connection. Okay, so that's my samples. All right, wanna do some great search? Yeah, any questions or we just wanna. Keep going. Let's get going. Wait. The Great Search, brought to you by Digikey and Ada from Thanks Digikey. This is the time of the week, every single week when Lady80 is their power of engineering to help you, yes you. Find the things you need on digikey.com, Lady80. What is this week's Great Search? I'm glad you asked. So this week's Great Search is, I just made a break up order for the DS4420, which is a really adorable mono audio amplifier with I squared C volume control. So it's analog volume, you have analog in and analog out, but then in between, you have an I squared C, you know, level control, which is kind of handy. Like you can, you know, you don't wanna have a volume knob and you don't wanna go digital and back out. It's fairly inexpensive. And as I was working on it, I was like, ah, you don't be really cool if there was a stereo version. So I was like, let's find a stereo version. So let's go to the, sorry, let's go to the computer and I'll show the DS4420. So this is, there's only one in stock because I just bought a bunch. I've learned my lesson. I don't do a great search and show something cool that I need without me purchasing the number that I need. So I bought, I bought up a bunch, although there are, you know, there'll be more available soon. So the DS, this is up the day sheet. So this chip, like I said, it is a amplifier for audio applications. It has iSquared C out, sorry, iSquared C control, three address pins, audio out, audio in, differential, you know, analog ground. And then when you go down, down, down, down, down, down, down, you can see basically there's like a control register. You can set the gain, mute and standby. So handy, but again, it's mono. So I wanted to find something similar but stereo instead of mono. Also like, wow, 74 weeks, nuts. All right, so let's go to audio amplifiers. And so this is interesting because what I want that especially the iSquared C control part is a little bit weird because there isn't like an interface box, right? There's a box here that said like, okay, SPI, iSquared C, whatever, but there isn't. And so we're gonna have to use, kind of, I used a new technique to find this part. So let's start with active and preliminary. So I only want stuff that's out or about to come out. Okay, great. So there's now 2,000 parts. So next up, you know, there's this long list and you see they all have like features. And again, the feature I want is iSquared C, but you know, it's like there's no way to search for just iSquared C. So what I did is I tried, well, what if I just put in the filter here? And that was good except that because you see there's a sort of like superscript iSquared C, it didn't come up in the features, which is something I'll tell DigiQ they should alias. So instead, I went down here and I found the superscript 2 and I went back up here and then I changed this to filter on these. And then I'll say that, you know, there's some of these are i2S and you know, I kind of tried to remove as many as I could have them because I don't want i2S, I want true analog. And again, that's not a searchable thing, but I also didn't, I kind of didn't care too much because there weren't that many and there's a good enough. Okay, so apply. So those are 200. Next up, I remember I want it to be stereo. So definitely don't want mono with mono headphones. I don't want one channel, I want two channel. Stereo, stereo, stereo, stereo. Okay, cool, I'm gonna apply this filter. All right, great, now we're talking. So the other thing that came up as I was searching is there was a lot of BGA parts and I like I had enough stuff going on in my life. I do not need to throw a BGA, I mean, I get it because it's like they're meant for like headphones or like portable things, they need to be very small. I do not want BGA and so I'm going to make sure that I select only the non BGA parts. So T-Sops, okay, QFN, no BGA, no BGA, no BGA. I mean, I'm not gonna get some of that 99 pins anyways but I just basically did no BGA and that gives me down to 31 parts. So now I'm really looking at only the things that are available. Now most of them seem to seem to be quite a few in stock. So let's look by price. So there were a couple. So this one was kind of nice, it's not in stock. So I kind of, it does do, which doesn't attend, it's a class AB. So it's an audio amplifier with I squared C. You can see it has a little headphone and there's audio in and there's I2C. So it's analog, analog, and then if you scroll down, they tell you, it also has basically there's volume control and it looks like there's like a base boost you can turn on to. So you can turn on, you know, a non-linear gain so that the lower frequencies have a little bit more of a boost, which kind of sometimes helps with cheap headphones that don't have low frequency response. Bad news is it's not in stock and who knows what it will be in stock. So that's what I found, this wasn't too bad. It's like a dollar in tape and reel. It's a TPA6130. So this part looked not too bad. One thing I liked about it, it has wide power supply, it has the audio, 64 step audio, taper, it comes in QFN and VGA, but I don't have to do VGA, I do QFN. And, you know, it's a pretty simplified schematic. It's not too complicated. So the thing is that you have a little charge pump inside, probably to drive that headphone and get it, I wonder if they have a false ground. Yeah, they do a false ground. So it really is meant for headphones. There's no blocking caps because it lifts, it just makes sure that the headphone output is centered around the grounds, there's no DC offset. So it's actually kind of a nice design. And then if you go down, you know, they also show you, hey, you know, here's what, here's how we do it with the bias voltage versus having it ground centered. Audio taper, you know, basically, they do nominal DB gain to, looks like negative 100 to four DB. And you just program, you basically just like, write the register, nothing going on. Let's see, there's a few registers. It looks like you can mute each left and right. And you can set the volume. So you have basically four or five registers, very simple, but very effective. Actually, I really like this design. So I think I'm gonna go with this one. The TPA 6130, that's what I want. It's I squared C, voltage range, no cap required on your output headphone drive. And stereo input and output. This is my pick. That's great search. Okay. All right. And thanks so much to folks for helping each other out in the chat. There was a couple things. Here's one question for that hub. Like thing, will it support multiple I squared C addresses? Answer, yes, looks like it available addresses. So it looks like the question and answer were answered in terms. Well, that hub is a passive hub. It just connects all the pins together. We have a different board that we already saw. I'm sorry, the DS442. Oh, that, yes, it supports multiple addresses. There's an address selector, jumpers of the buck. Yeah, there's eight total. Cool. But like, why not just have stereo and then now you need only four. Okay, we're gonna go back to work behind the scenes here. We have a bunch of stuff we're posting up. We have some time lapses. Bunch of neat stuff coming up on Ask an Engineer this week. Thank you so much everybody for tuning in tonight. Lots of exciting new products ahead. All right, thank you everybody. Not everybody. Bye.