 Alright, this week's IMPI. It's Amphenol. It's from Amphenol Advanced Sensors. We featured them like two years ago for their infrared temperature sensors and this week we're sliding over slightly and I'm going to talk about a CO2 sensor that they just released. I should saw it on ditchikey.com slash new. It is the T6793. There's two versions. There's the 2K and the 5K PPM module. It's a beautiful gold sensor. This is a NDIR CO2 sensor. Very handy and very timely. It's a good time to release NDIR CO2 sensors. Why is that? Oh, you can start. Here's the details about it. You can see it next to a pencil. It's very compact, very small. I think Tel Air is the subbrand that makes this and it's a nicely calibrated CO2 sensor with a lot of different output modes, which is kind of neat. CO2. It's everywhere. It's in everything we breathe. We like to exhale CO2 and inhale oxygen and plants to the opposite. We live on this planet. CO2 levels have been going up a little bit over time, which is one of the issues we have with climate change on this planet. Monitoring CO2 is something that scientists do a lot. Recently in the last couple years, more people care about CO2 because it's an excellent way to determine the ventilation of indoor spaces. Outside air is 400 ppm, basically. It starts at 400 if you have the windows open, but if the windows are closed and you're breathing and there's a lot of people and you're in a classroom and there's not a lot of outside air circulation because there's no ventilation. CO2 level will start to rise, rise, rise. We've made projects with CO2 monitors like this one Carter did, just got this adorable cabin and some trees in the background showing that the indoor CO2 level is 782. As long as under a thousand, you're pretty good to go. We had one developer who was working on a CO2 project and they were showing off their readings and it was like 2,000 plus. I was like, hey, you want to open the window? I think Digikey also came by. They built their projects and they're like, wow, the basement needs more ventilation. It's good to know because it can make you a little drowsy as well as it means that there might not be enough air circulation if you want to reduce flu or COVID transmission because there's just not enough air circulation to keep the air moving around. We have sensors in the store like this ENS-160 and they're a lot less expensive, effective CO2 sensors, but these I just want to make sure people know that there are two kinds of sensors for CO2. There's like true NDIR CO2 sensors which are kind of expensive. They're like 50 bucks plus and then there's the effective CO2 sensors and this, if it says ECO2, what it means is it's actually a sensor that uses MOX, volatile organic compound sensing elements. It's a resistive, it's a doped material that when volatile organic compounds are nearby, it changes the resistance and you can tell if there's gases or volatile organic compounds like ethanol and stuff. By measuring that, you can use it to estimate air quality and the effective CO2. Here you see this ECO2 reading of about 700 ppm, which is again, if we're indoors, that's about right. The only thing is this isn't a true CO2 sensor. It's estimating it based on overall volatile organic compounds in the air. Whereas this sensor, the T6793, is a true NDIR infrared sensor. It uses how IR light is affected by CO2 concentrations calibrated to give you a really good precision, accurate reading. This one, it has really good temperature dependence and accuracy plus or minus 45 ppm plus 3% of reading, which is really great. You can always calibrate it to be even better. There's a built-in algorithm that if this is being used for outdoor reading or readings indoor where there will eventually have an open window so that the minimal CO2 ppm is 400, it will recalibrate because it does drift a little bit over time. The module is quite small. I'll show it on the overhead, which I really like. There's a lot of interfaces, which I thought was kind of like the powerful, the size and the interface is what kind of sets this module apart, as well as, of course, the accuracy. It has a 6-pin IO header. You can see there's a typo, I think. It's TX-SDA. I think it's RX-SCL. There's power and ground, which you want to give it 5 volts, which is not uncommon. You need 200 mA for the sensor peak, about 100 average. There's control test, PWM output, UART output, and I-squared-C output. Oh, and sorry, can you just get that out of the world? The first update I thought was interesting was PWM. There's two modes of PWM. There's a 1 kHz, and I think there's a 10 kHz version, which I thought was really neat. If you have a sensor that doesn't have an analog input, maybe doesn't even have I-squared-C, but can read PWM pulse width, you can use that. It'll always go low for two milliseconds, high for two milliseconds, and then you can calculate the PPM based on the PWM width. I thought that was kind of neat. I don't have any sensors offhand. I don't have any macros offhand that don't have UART or I-squared-C, but do have PWM. But if you're dealing with, there's some legacy systems that use old-style sensors, this can be used in those places. So I-squared-C, so this is my favorite interface. So you can use modbus I-squared-C registers, you write addresses, and then you can read versions of the firmware, the PPM reset device. So basic stuff, the ABC logic enabled, disabled, that's the auto calibration based on if it's outdoor enough to or getting low enough measurements, it'll eventually reach 400 PPM. You can measure on demand for low current, or you can of course have it being continuous mode and get measurements every five seconds. So I like I-squared-C, but that's the second option. And then the third option is UART, and they also have RS485 transceiver support, which I thought was really smart because a lot of people do want to have the sensor far away. They want to use RS485 to do a differential signal from far away. I-squared-C doesn't work for far away. I wouldn't use PWM for long distance, but 485, you know, yeah, why not, as long as you give it good power. So plain UART, I think 9600 BOD, or RS485. So that's all good. So again, most CO2 sensors don't have all those options. They have maybe one or two. I like that there is on this one, there's four or five different ways you can connect to it. There is some code that I found on Github. It's a little old, it's for earlier versions, but I think the register maps are the same, using I-squared-C for their sensor. That said, you know, the protocol is pretty simple. I think, you know, you would read this code, you'd look at the data sheet, the app note, with the I-squared-C instructions, and they have example pseudocode in the app note for I-squared-C as well. So that's the sensor, so I thought I would- Available on Digikey. It's in stock. It's one of those things that you can actually get. At the time of this printing, by printing, I mean screenshot and sending photons, there is 999 in stock. Yes, so maybe we can show it on the overhead because I want to show, it's much smaller than I expected. I really thought that this would be larger. A lot of CO2 sensors are quite big. That looks gigantic on the screen. It looks, what's a really good photo. It's like, ooh, golden, but it's actually, you know, very tiny. It's like a miniature satellite. Yeah, and then this is the IO, and then this is a little mic controller that does the readings and interfacing for you. But it's a very cute little sensor, and I like that, you know, it's through a hole, and there's, you know, you can put headers on both sides. You can just have it plug into your system, because these only last, they're not meant to last more than, you know, maybe five, 10, 15 years before maybe they have to be pulled or, you know, they can get contaminated, especially if they're in a caustic environment. So they're easy to replace. And that is this week's IonMPI.