 and welcome to Descalade Aida. Hey everybody, welcome to Descalade Aida. I hope everyone had a great Circuit Python day on Friday. I know we did. The show in total was amazing. I know there were talks and events and codes and sprints and more and more and more. Ms. Valade Aida, do we have any updates for things or tell people go to Silicon? Yeah, we did all that. We did all that. We're just gonna jump right into Descalade Aida this week. Valade Aida, what is on your desk this week? You're here for the electronics and so am I. So let's get into it. Okay, so last week we talked about light sensors and one of the things I was talking about doing was designing a circuit playground with an RP2040, which doesn't have a lot of analog inputs. And so I wanted to replace the analog sensor, the analog light sensor with the LTR329, which I think I showed off. So let's just bump really quickly to the copy and I can just show this off real fast. So this is the sensor that we found because it's a really good price. It's like 30, 20 cents. I squared C sensor and it's in stock. I love things that are in stock right now. So I got some, pardon me, I got some of those sensors in hand and one of the things that is like my favorite thing in the world is when a sensor has the same footprint as another sensor because it means I can use, I don't have to design a new board because like the designing of the hardware, it doesn't take a long time to design the hardware but it does take a long time to order the PCB and get it back and get all the parts and like you place it by hand. So one of the cool things is that as I was working on this, I noticed that this had the same footprint as the GUVB, this sensor, it's made by a different company but just coincidentally it's got that same four pin package and so what's neat is I go to the overhead real fast. I can show this off, we'll zoom in too because these are small parts. Okay, so this is, you can kind of see behind the Sharpie. It was a GUVB sensor and I just hot aired the old sensor off and I put that LTR329 on and not only is the package the same but the pins were the same. Again, total weirdo coincidence I think because it's a totally different company. Oftentimes when it's the same company, you will see they try not to change, they try to keep the footprints the same because it makes everybody's lives a lot easier. So if you've used the VL53 series of distance sensors from ST, there's like the VL53 and VL53 LC4 and then VL54, whatever, there's like five or six different chip that they all have the same pin out in the same package. Ditto with a lot of sensors and sensors the same like the BMP280, the BME280, the BME680 all, they're a little bit bigger or smaller but the pads are the same and so it actually makes, if I remember correctly so it just makes it a little easier to use those sensors all together. Maybe BMP280, the BME280 and I think maybe the BME, whatever, 388, I don't remember but they're very similar. Anyways, so I popped this on and then let's go back to the computer and I wrote a quick driver for it. It lives here, LTR 329. Again, you know, one of the things I've been doing lately is I've been writing my drivers in Circuit Python Python using a FT232H as an I-squared C converter and then I tested on hardware but the rapid coding, I do on a computer and it's because it's so much easier to debug and it's quick, I can see I-squared C traces. It's like easier to print stuff out than Arduino where like every time you do something, you have to recompile. So I do save, I can write a driver in a couple of hours. It's much faster and there's like, it's like creating a ray and the array is created and you don't have to worry about it. Memory's managed for you, it's kind of a blessing. Of course, it uses more memory but it runs on a computer. You know, I learned a couple of things about the ALS 329. So hold on, let's go back to, oh wait, I actually have the driver here. So the 329 is, it's very simple. It only has four pins, it has two diodes. One is visible plus IR and one is IR. The only thing that's a little bit interesting about the sensor is you really have to read those two at the same time in one I-squared C transaction. The way that the data ready bit works is it's expecting you to read both at the same time. So I kind of have to like mess with the driver a little bit and the examples to make it clear that if you're gonna use the data ready bit because when you read it, it clears and if it like happens to go, like if you're reading the two, in two I-squared C transactions, you know, eventually the interrupt comes in between and you end up clearing it, you don't realize you've cleared it. Isn't just a detail. But yeah, otherwise this was, you know, pretty easy sensor to get going and then I'll just plug it into my FT-232 here. Looks like I got my board and the simple test and you know, it's just a little bit to the side here so you can see, you know, I just got data coming out. One thing that is interesting is, you know, you can overwhelm the sensor a little. Yeah, you can see like visible, it gets negative. You can overwhelm the sensor and there's another bit for data valid, like if it overflows, like you will actually, you can test the bit. So the advanced example does all that, like the data validity. Oops, this seems to happen when I, yeah, my cable's not plugged in all the way. There you go. So the data, there's a couple of like cool bits and stuff. So it's a good sensor. One thing that is nice is it does IR as well as visible and I was talking to Mr. LaDieta, we were out having lunch and while we were walking to lunch, I was like, oh, you know what the cool things is because it has visible and infrared, I could put an IR LED, you know, somewhere on the board and then use this as a distance sensor. Not a great distance sensor, but you know, IR is way better than light because light is affected by ambient light a lot more, whereas, you know, infrared is not. Now, the only thing is you can't do PWM infrared, which is like the right way to do, like the pulses, but I'm willing to try it, see how it goes. So there's that sensor. And then while I was here, you know, I was, I also looked at, if you remember, I also looked at the big sister, which is the LTR-303. And this sensor is very similar to the LTR-329. So it's a couple of cents more, but it has six pins and it has an interrupt pin, which is like, you know, otherwise it's actually interesting. The register map is the same. It just has like this interrupt pin and the package is slightly different. Let me see if I can find a photo of the package. Yeah, it's got six pads instead of four. But again, you know, this was, I was kind of like, ah, you know, I wonder if it has the same package as the LTR-390, you know, which is a very, it's a UV only sensor, but it's very similar. It's a six pin light sensor. And it turns out that, yes, it has the exact same pin out. And so I, let's go to the overhead. I took an LTR, I just like did this way before the show. I took an LTR-390 and I hot aired the old sensor off and then I plugged the new sensor in. And again, the register maps are the same. And so when I run it, I actually, I get data out of this just the same. So all I have to do is update the library to add interrupt functionality. And basically the driver will be done. So I got, you know, these two sensors going and then I also, while I was at it, I was like, well, I might as well get this, this Goove B or Goove A sensor, this I squared C UV sensor that I designed like months and months ago. So I got this going and, you know, it's an interesting sensor. It's from Genicom and like they make, you know, they're like a Korean company. They don't make a lot of stuff. They do make these sensors and they work. I'll say the datasheet is a little bit like challenging. There's a couple of different versions. Some of them are missing data. Like some of them are like to be determined. I actually did find enough data to get UV information from it. There's a calculation also for doing UV index from UVA or UVB, but we took it out. There was a little video where we posted probably tomorrow the next day where we went out to the park and I had it on this feather and I have it printing out the UV raw data and UV index. And like the index went up to like, it was like 15, like it was really sunny out, but it wasn't UV index 15. So I got to figure out what's up with the calculation. This is kind of like what I do. It's like, you know, what, like, what's the difference between like Adafruit drivers and other drivers? It's like, I'll actually like email the company and try to get an answer and a datasheet and the example code. And I'll make the library do the right thing. Cause I found some people who tried to do the index calculation and they all, I don't think they did it right. So eh, whatever. But hopefully I'll be able to figure that out. If not, the data, the raw count data is good and it comes in UVA and UVB versions. So it's meant for scientific, you know, or outdoor measurements. I'd love to have a UVC sensor. UVC sensors are hard to get. They tend to be a lot more expensive and I haven't found one yet that is I squared C, you know, and then just as a UVC band. But, you know, that's cool. So there's a lot of light sensors this week. And then I also wrapped up the tester for the Max 17 048. You all remember two weeks ago, talked about this chip because the LC 709203 battery charger, sorry, battery monitor, fuel gauge that we've been using is, not to discontinued, but they're kind of like solely getting rid of it or it's end of line and we can still get it but eventually that's gonna end. Even though I've found that some parts are easier to get these days, I need to have an alternative and this is a fairly inexpensive alternative. It's like about a dollar a piece, maybe a little bit less. It's very low power. What's neat is that the pinout of the breakout board and the size of the breakout is exactly the same because it's pretty much the same. So this tester is actually designed for the LC 709 but I just swapped it out with, you know, this breakout updated the code and, you know, it does a quick test. It just, you know, verifies it can read the analog voltage here. This is from the 3.3 volt line. Iceward C works, you know, I checked the interrupt and the quick start pin and if that's good, then it beeps. So this tester means probably be fabbing this week which is very exciting. Okay, I think that's all of my updates. All right, let's do a question and then then we'll do a great search. Cool. So the question is, I know you haven't done anything with the smaller NRF 52 chips but what would you recommend to do when trying to cope with the NRF soft device hex being bigger than the flash on the chip? I've tried smaller soft device files but I'm not sure how to proceed. Yeah, I have no idea. You're kind of on your own. I mean, if you're not using, if you're using the much smaller boards that are smaller chips, you need to use Nordix SDK. They designed it specifically for their stuff. They're gonna have code and examples. One of the things that we have to kind of remind people is we write code and we can test on our hardware. If we don't sell the hardware, we don't test it. So there's no real way for us to know if it works or if it doesn't work or how to fix it. So you're in uncharted forests or waters or exploring new lands but Nordic does have really good tech support. I'm sure it'll be able to help you. Let's do a great search. Okay. The great search brought to you by a different Digikey. Thanks Digikey. Every single week, Lady of the User Powers of Engineering to help you find parts that you're looking for on digikey.com. Lady of the what is this week's great search? I'm glad you asked this one. I'm pulling it up right now. So this week's great search. You'll never believe it. It's a part that's no longer available. But I also want to use this sort of as an excuse to look into and research some class of sensors that is near and dear to my heart. But you know, there's, it's always kind of like funky learning about them which is gas and volatile organic compound sensors. So the board that we've been making and we can maybe go to the computer is the CCS-811. This is actually one of the first, you know, low-cost, I squared C gas sensors available. There are gas sensors that are analog. Let's see, where are a few gas sensors? There's like this. This is a traditional kind of gas sensor. It's, you know, an analog output. You have to turn on the heater and you have to kind of do a little bit of management and then read it. What's nice is that since, you know, these sensors are quite good. And that's what, this is how you measure gases depending on how the sensor is doped. It can measure, you know, I think carbon oxide and alcohol and ethanes and usually they make a whole, you know, like nitrogen oxides, whatever. They usually can sense a whole bunch of things at once. Even analog output and then they have to be calibrated. But for a lot of people, they just want to measure like air quality. Like, you know, is there alcohol or gas in the area? This is different than carbon dioxide sensors which are also gas sensors but they usually use a different methodology. We, you know, we have a couple CO2 sensors that the good ones that I really like are the SCD 30 and the SCD 40. SCD 30 is, you know, an amazing gas sensor. It has, you know, an NDIR sensor tube and it's like really well calibrated and they're very, very good sensors and they're true CO2 sensors. Most other sensors are kind of the guess, the CO2 based on volatile organic compounds. So, hold on, let me go back. So usually when you do, let's make a guess. You know, a sensor like the, you know, SGP 30, for example, it'll say volatile organic compounds and ECO2, effective CO2. So it's kind of trying to guess, calculate the CO2 based on the volatile organic compounds. It's not true, but it does a fairly good job. But, you know, these are usually used, you know, air quality sensors indoor and outdoor, not particulate, but for gases. Also lots of scientific use cases as well. But, so as I mentioned, the CCS-811 was a classic one. One of the first ones, people rather liked it. But, and we kind of, for now we recommend the SGP 30, which is a pretty good sensor as an alternative. It's no longer manufactured. So, you know, there is an alternative for this chip. The, hold on, they recommend substitutes. They recommend the ENS 160, which I think is made by the same company, which is also a great sensor. The bad news is that you're like, what am I gonna get some? And it's like, you know, like happy new year 2023. Which, you know what, and I'm happy. I will, when that happens, I will probably pick some up and we'll make a breakout for this and all is good. But I wanted to find another gas sensor maybe in the meantime. Well, like while, while I wait for this to, to pop into stock. So, let's go to the gas sensor category. And I'm also, you know, it's interesting, I'm not looking for a direct replacement. I'm just kind of like seeing like what's, what's up in this category. So it's still kind of like a little vague. I'm looking for active designed only because that's where I'm at. And you know, I'm not actively looking again. I have other gas sensors. So it's something that's normally stocking. It doesn't have to be, you know, in stock today. One thing that I did notice, I just sorted by, you know, quantity available is a bunch of CO2 sensors popped up, which is, which is fine. But I actually, I don't, I don't want CO2 sensors. Those are, again, they're, they're kind of different than air quality sensors. So I selected everything. And then I, I unselected carbon dioxide. And I got me about 200, 200 things. So a couple of good things. So, you know, the SGP-40 is a sensor that I've used. It's kind of the next jet of the SGP-30. Again, it's a good sensor. You know, you can get data out of it. It does have this kind of secondary library that you need to use to actually do some, some calculations. That's not unusual. There's also apparently the SGP-41, which I didn't know about. So I'm actually going to check this out because it's like, I'm assuming this is just some improved version of the SGP-40. There's the SGP-40 CO2 sensor, which still made it through. And then there was this kind of interesting, the Zmods. What's interesting is I'd heard of these, but, you know, I'm kind of fascinated whenever I see something with 25,000 pieces in stock at Digikey, because it's kind of like, oh, this must be like somewhat popular because they would not stock that many of something if it wasn't. And so I was kind of like interested in looking at this a little bit more. So I'll do that in a moment. And there's a couple in that family as well. And then like you see, there's the Zmod 4,450, 4,510, you know, A version, B version. So there's a couple of these. There's the Senn-50, which actually contains an SGP-41. We covered this on INPI earlier, but really it looks like the Zmods are kind of like taken over. Like there's the SGPs and there's the SCDs, but these are the most interesting. So what's cool about these is they're from Renaissance, who does make sensors and such. Let's see if I can load up the data sheet. If not, I will, I'll just go to the, okay, so it's outdoor air quality sensor platform. So what's interesting about this sensor is for interfacing, at least it's I squared C. So that's kind of good. I'd like to see that. Like I don't like it when it's like, hey, we came with some weird ass interface. I squared C is pretty standard. Not worried about being able to communicate with it. The interesting thing is it does various measurements. It looks like it measures like nitrogen, dioxide, ozone, air quality. It's got, you know, it's a Mox-resistant sensor, like all of these are. And one of the things about Mox sensors, I will say just because, you know, I've used them a couple of times, is like that analog sensor I showed you earlier, there's not a lot going on with these. Like they are pretty much all made the same way. There's a few patents that expired probably and so people are making more of them. But like the concept is the same. Like once you've kind of dope it, you get this gas resistance and, you know, you have to calibrate a little bit, you have to normalize it, but you pretty much are just tracking this resistance and trying to convert that into, you know, a semi-calibrated output of what the air quality is. So there's good news and bad news about that. One good news is that, you know, technically once the patents expire and people know how to make these, it's not too difficult to just manufacture these gas sensors. The problem is is that there is, you know, as an outsider looking in, it seems like because the technology is quite simple, like not simple, but it's, you're just getting resistance value and then, you know, you track that and do whatever you need to with it. The firmware, the stuff that actually reads that resistance and calculates that to something is usually either baked into the chip, like the SGP30, or for more complicated stuff, it's kind of this external processor and it reminds me a little bit of 9DoF sensors or 6DoF sensors where, you know, you get accelerometer and gyrodata or magnetometer data, but then you have to fusion it together and that's where intellectual property kind of comes in and becomes a firmware issue. So, you know, I looked into this and it's an interesting chip, but here's the deal. You know, the data sheet is actually kind of empty. There's like really, you know, usually you open data sheets like registers and pins and bits and all that. There's kind of nothing here. They always have this like standard I squared C diagram and it's like, have you never heard of I squared C before? Like you read all about it and they always are like, hey, you use there's a stop it. It's like, yeah, cool, but then there's nothing after that because what you're expected to do is you don't, you have to submit a request to get the firmware and the firmware comes as a binary blob that you then link in with your application. So, you know, they have binaries for like most popular platforms like, you know, ARM Cortex M0s and expressive chips. You don't get to see the code. You feed it, you know, you feed it to data and out pops this algorithmic thing. It also reminds you a little bit of capacitive touch. Like microchip does the same thing with Qchutch. Capacitive touch is just a capacitive read. There's not a lot going on. There's a couple of different ways of doing the waveform but for the most part you're reading capacitive data and it floats around and then it spikes and it goes down. So the intellectual property is how you filter that data and they don't wanna control that. And so, you know, these days when you get Qchutch it's not on the chip giving you raw data. Instead you have to, I mean, you can't get through our data sometimes but they sort of hide that. Instead you're supposed to use this binary interface. So, you know, it's interesting seeing how sensors have changed. One thing I do like about SincereN is they don't have that, like when you use their sensors they really do pop out in I-squared C whatever data you need it's there. It's like CO2 level, you read the register, you do a little bit of like shifting math or whatever out pops the number. With these sensors, you know, it is a little bit less expensive, you'll see it's like, you know, 350 instead of 510 or whatever. But in exchange, what they do is they don't have a powerful processor on the chip. You have to use this binary blob instead. So, you know, it's interesting especially for people who are used to temperature humidity sensors that are just very simplistic in their functionality to sensors that really are mostly a front end to a firmware processing system. And you need, you know, I don't think that maybe they have a library for AVR8 bit but, you know, they probably kind of require Cortex-M0 to do a lot of the calculation. And it's of course under NDA. So, you know, it's interesting. I'm gonna take a look at this chip and, you know, maybe I can see if they've released a library that I can use because it's gonna be tough for me to write a library when the firmware's under NDA. But we'll see what's possible. So this is the Zmod 4510, I guess this is the new, this is the new way of the sensor. So folks, gotta get used to it. That's a great search. All right. Okay. So that's our show for tonight. I wanna make sure there's nothing I'm gonna take care of. Nope. Questions? We're all good. I'm gonna get us out. Okay. See you throughout the week for a series of AVR8 shows. Thanks for spending your time with us. We very much appreciate it. And we'll see you around. Bye everybody.