 Welcome to this lady Ada everybody and welcome to my desk. It's me lady Ada did a bunch of tax stuff this week So not a ton of hardware, but I did get some tester stuff working And hopefully the week or two will file our taxes and we'll be done with that and then we can move on to more hardware So let's go to the overhead. I'll show awesome stuff. I was hacking on So I did a lot this week as I worked on some testers Because there's a bunch of new products coming out So the first one is the sht45 trinky So this board Think I mentioned this a couple weeks ago We have a lot of samd 21 e18s in stock because we had to buy two years with the stock and then like we scheduled it out Like oh send it to us every four months we'll get like a quarter's worth and you know every three to four months and We're good for like two years and then microchips like anyways We're gonna send it all to you at once and I'm like I don't want it at once and they're like We're sending it to you at once and it's too late. You already bought it So I have a lot so we're gonna do a lot of trinkets. So here is a 70 21 e18 base trinky which has a samd 21 chip a reset button the neopixel and sht45 and you see little cutout You know if you're using an sht45, which is like a kind of a high quality temperature humidity sensor I think it's like 1% Humidity accurate There's a little self heating so the temperature is like point five degrees C But it's like a little higher than ambient because it's Measuring the heating and especially if you have the self heat the heating element on it's gonna self heat even more But you know, you might as well isolate it from like the LED and the microcontroller. So there's a little cutout To isolate it thermally. So there's no thermal conduction coming through the PCB. The only trade-off is now there's less dissipation for The self-heating is like you can't really win one or the other Anyway, so this board's done and so I decided to do the tester next because we need to get it finished So the way this tester works is I use a little extension because this plugs in right into a USB port and then Hopefully this tester will work. It's a live live demo Uh, you know, it kind of like looks for the microcontroller. There's the SWD and SWC pins on the bottom And then when you line it up, it's like, oh, I found your chip could work and then It'll program And then it will test the output and then it's done So and then this LED blinks to let you know every time it transmits data So that the factory test that's programmed into this transmits Over serial of csv where like the serial number because the chip is a serial number The temperature and the humidity and then whether the the touch is is capacitive touch is being touched. So pretty easy But one of the things I had to do is You know, a lot of the, you know, the Other tricky code is still running on a tnc36 and I've because I can't can't get the tnc36 anymore It's like I have too many samd21s and not enough tnc36s I had to be pico-fied. So this was pico-fied. So it's great. So we'll get this in the store real soon um, and also pico-fied this esp 32 um v2 feather So this is one of the board, you know, I had to do a lot of redesigns So I redesigned our our classic hazard 32 feather um, and we weren't testing it with a Raspberry Pi and that was like totally cool. There's nothing wrong with that but The issue is that like people would accidentally unplug the raspberry pi or like eventually like it had to f-sick or something and so It was like not flaky, but I just wanted to have something a little bit more durable. So this um, it's it This is only taking nine seconds because the um Firmware's already been programmed so it didn't have to reprogram the firmware did the test On a raspberry pi the whole tight test takes like 19 seconds 18 seconds and then on this if this wasn't a race chip It would take like 26. It takes like 10 seconds more um, but I think it's worth it because again, like, you know, this is like Solid state solid state, um, like there's no sd card that can fill up or fly across the room or You know, like get corrupted and and whatever. Um, so I you know I think tacked an excellent job with making this um Really fast. So it's it's pretty amazing. You know, it's only 10 seconds slower and it's An rp20 40. That's bit banging with pio usb host talking to the usb serial chip On here and doing the reset sync and program and so it's like you're not going to get the highest speed usb cdc Um, you know you'll get 12 megabit in theory, but it's like There's still more delays than you will on the usb host control over raspberry pi. It's going to be much much faster One thing that tack did implement, which I really love is the stub and compressed firmware uploader So on the esp 32 There's this thing called this there's a built-in boot loader and it totally works You can program without using a stub but If you want then you have to send like every byte one at a time And if you want to do it faster what you can do is compress the firmware Like a gzip or whatever or a zip and then you send the compressed File over and then uncompresses and burns it but you need to have a secondary boot loader and that's called the stub so this um firmware on rp20 40 Sends the stub and then resynchronizes and then sends a compressed Uh version of the firmware so it takes it takes out like a lot less time because the thing that takes The most time well erasing the flash takes time, but that usb to serial to serial to the boot loader Also takes a bunch of time. So, um, this is all in um the Uh, I think it's it's they called the test bed library. So, um, we'll go quickly to the computer because I'm sure people are going to be like Where can I find this? It's under test bed So we did, you know publish everything open. So there's examples not like the code for this exact tester isn't there But there's code that's you know, very close. So you know program sd card um program esp 30 from an sd card or uh esp over ur or cdc So, you know, you'll you'll have to change your pins for whatever hardware you're using but um, it does work So it's kind of nice. And then the last tester, um, I worked on let's go back to the overhead And then we'll get into the great search um, so last tester I did is for the uh hv Yeah, so this is the prototype But the high voltage updi programmer So we've already got the updi programmer in the store And that just does like a plane through your five volt logic. Um, the pin that's used for updi can't be a reset or gpio It can only be for updi And that works great. Um, but I did want to make a programmer that could do the high voltage pulse So this board, I think you guys remember we designed this like a month or two ago It has a 12 volt boost converter. That's the inductor and capacitor and the little chip And then there's an analog switch here an analog switch like when you basically send an rts pulse It'll very quickly Switch over to the 12 volts and there'll be like a 100 microsecond 12 volt pulse and then it'll go back to Um, the usb serial data. So it's just when you know, you toggle rts And it sends this pulse and it gets you into to boot loading mode and it works great with the arduino id But as you can see, I kind of messed up the design um Because I forgot that it cast 12 volts on the data line duh, and so I had to make a couple changes Um, since the parts are really small to see What I'll do is give me a second. I'll open up the um the tester Uh See where's the tester? It's called Silent second UPDI How did I lose that? Oh, that's weird. Oh, here you go. All right. Can you go to the computer? so many files um Okay So the first thing I did is I read the serial data from pin zero, which is like the hardware you are Rx But obviously I don't want the 12 volt signal to get into this pin because even though the rp20 40 is um Five volts friendly. It's not 12 volt friendly. There's nothing 12 volt friendly. So I've got this little zener clamp here And the way this works here's a zener clamp is whatever voltage comes here the voltage drop from here to Um this which is no more than 3.6 volts from the zener the zener diode when biased reversed You know, it'll clamp at 3.6 ish volts um So I could have gotten a 3.3 volt zener, but I happen to have 3.6 is in stock. So I just use that So if this is 12 volts, it's 12 minus 4 whatever milliamps Um, but that gets sunk by the zener and so this voltage never gets above 3.6 Also never goes, of course below zero because this diode the other way will also reverse bias Sorry, the forward bias to be no more than 0.7 ish volts drop So this protects the rx pin from the 12 volt signal There's a little bit of like it goes it goes up a little bit with the 12 volts, but like half a volt It doesn't go above four volts. It's that's good to go and then here So I also want to measure the 12 volt pulse, right? So I measure the the u-art data, but then I have to measure the pulse the issue I had with this is in the Um on the board we use like the usb bit bang on the rp2040. This is the usb host So it's bit banging usb and I actually said, you know, I can over the cdc protocol say, you know toggle on the rts pin Maybe I'll show that really briefly. So here I can uh I test the 12 volt by being like, okay, set the rts pulse set the rts true And then that'll cause the pulse then I have to read the analog voltage and I do the math And then I just make sure that it's greater than 10 volts the problem I had though is the tini usb library was blocking enough or it was delayed enough that by the time I told it, okay toggle the rts And then I got back to the arduino code to read the analog voltage the time had already passed the pulse The pulse is not that wide So what I did is I made like a little like, you know, peak hold like that's not a sample hold. It's a little like peak holder So basically, um, it charges up this 10 micro farad capacitor through the the 12 volt charges is 10 micro farad capacitor through the diode But the diode has a low reverse Leakage and so the voltage can't leave this way And then going through here. It's a resistor divider with 11 Kilo ohms of resistance and that basically causes the voltage to you know, kind of It it charges fast because it charges quickly through this diode But then this charges slowly and so instead of getting a little pulse It kind of turns into this like a long slid ramp It gives me plenty of time to um to test and so, you know now um You know connect over serial it test the serial data it tests that the serial is self you know reading because updi is tied together through a what care resistor And then finally test the 12 volt pulse gets, you know, 10 and a half volts It's good to go. Um, so this test is done And I'm going to order new pcb. So I don't have this like crazy blue wire hacking and that'll get into this store Okay So let's uh, okay great. We're done here. We're done here We're done here. So let's um, let me show you one more last board and then we'll go into Uh, the great search second Okay, let's go to the great search. We'll talk about this more Great search brought to you by digikey native for it every single weekly data user power of engineering I'll be using find things on digikey.com my data. What is the great search of the week this week? Okay So this week, uh, for folks who remember like about a year ago. Yeah, it was a year ago We did the great search on getting high powered infrared emitters And we made this board that um, has a right angle and like a vertical and a horizontal emitter So that you can just blast ir for making like tvb guns or infrared remote Mimickers or just you want to illuminate ir somewhere? Um, and this has been working great. I love this board. It's all good. But then um, we had a request from the internal team To make the opposite. I want a receiver something that receives infrared because we have these like, uh remote receiver We had these little dudads and they're wonderful and everything but they're really hard to mount and you have to like solder these little wires and like I mean, they work great and everything but um Folks wanted something that was like plug-and-play mountable Um, maybe even has a little led to tell you that the signal was received a little debugging information So I um Oh, this is not right angle, but this is Uh, a design that I came up with um So it has a white angle Um receiver and a vertical receiver And then there's a switch to go between the two and the reason there's a switch Like why don't just tie them together is because they're push pull and I don't want the outputs to fight each other If one's getting a slightly different signal and I don't want them to corrupt the signal So you just decide did you want the you know vertical style or the horizontal style? Um, Which is cool and everything Um, but one thing about the these receiver modules These are like smt versions of that through hole is that they're fixed in their frequency the carrier frequency Which is like 99 percent of the time 38 kilohertz But sometimes it isn't like some people have like remotes that are 50 kilohertz 40 kilohertz, you know by 28 whatever and um Even though these have a little bit of fluctuation. They're not definitely not going to go to 40 Sorry to 45 56 like they're there's limitations. And so I was reading about learning remote um receivers that are They don't do the full decoding, but they will give you the carrier signal Modulated so they'll just kind of they'll at least give you like the cleaned up They'll basically give you what you set to the ir led With the the carrier wave in place you can determine what the frequency is and like there are situations I think that's going to be really handy One when you want to get like the raw signal from the ir But also maybe like, you know, there's there are I think like programs for like raspberry pi or whatever that can do IR remote Learning so you can learn about the remote and then duplicate it or they're repeaters So I thought that could be kind of interesting and we actually had and you know as it was funny is like I'd love like when I researched something and then like the one of the links is to learn and I'm like Well, so like, uh, chris young did an infrared He did Sorry, I'm gonna find where it is because he did a lot of remote projects This one so turned out he actually was using um A tcmp learner chip because somebody linked to this So this was really cool. Um I was like, well, what what is a learner chip and then you like read the data sheet? Basically, like I said, it has a wide band of receiving. So let's go to do the key and find A wide band infrared receiver So let's look for infrared Receiver I before e except after c guys. Okay photo detectors are about receivers So let's go to the category. Okay, 1342 and then what's nice is that I was like, well like, yeah Here's the center frequency. Remember I said like almost all them are 38 kilohertz But there are some that go above and some that go fairly low And then there was like you could there was one that you could select the center frequency and I was like bomb. I'm done Yeah, I was like, this is gonna be the shortest Great search in the history of great searches. And then I was like, wow, there's even some in stock Chip shortage is over. So I clicked on the tcmp 7 7 0 0 0 0 And I was like, this is really cool Because yeah, it will give you the modulated output. That's their thing. They're like there's a little bit of delay But they'll give you the modulated output. It's good from You know, a wide range of wavelengths that's 840 and 940 and you know, even up to like 1000 nanometers easy pick and place part, but But but but it's no longer manufactured and not available Um, but there are substitutes. What's interesting is the substitutes did not show up here So if you look There was only one Well, too, there's the tr version the tt version down here and like this one But there was no others. So what I did is I was like, well, okay, let me look at what's going on And I was like, well, there's like the tc. I was like, oh, there's tcmp 59 960. So there are a couple options Including one that was the through-hole version that was in that guide But then I was like looking at this and what I didn't understand was why what was all the differences because if you search for And I had like was 96 like the strength of the frequency and I didn't really want to dig through all the data sheets So what I ended up doing is um I found this document on viché And they make like the most infrared receivers like they they're kind of they kind of run they kind of run this place And thank you, Sebastian Schaefer who did a really nice job of explaining all the part numbers And this is like a great document I rarely see this where they really explain like what every number in letter means because then you know what you're searching for so The application and they're like, oh if it's tcmp That means it's a learning remote and I'm like great. That's exactly what I'm looking for And then they have this like icy type which you can ignore and then I was like, well, what is the 96? Like there's 96 95 90 whatever so The first number is the package And I don't know if they have the photos of the package. They don't have the photo But like all the different shapes are different. They have like different names for them Like heimdall who's like in norse god And velobog, which also sounds like a Norse god, but I'm not sure And then like mold really mold cast. So I guess like package information And then the auto game, um, I'm assuming this is automatic gain circuitry. So it's like how it does um gain detection and then the Frequency and so we want zero zero because there's no band pass. It's like it lets through anything within that frequency range So if we go back Well, let's actually search for tsmp Right because we learned from this that anything that's tsmp will be a repeater or learner part and Let's Now look at active because like we've learned some are not available to supply and then You know, there's different sensing distances, but maybe that doesn't matter and this is a thing they do have a center frequency, but like The categorization doesn't realize that the frequency is wide, you know, I mean, it's like there is the center is 38 But it's like it doesn't narrow band. It's a wide band. That's okay um So a couple different options. So it looks like all of them are like ts Well, let's look at the ones that are just like normally stocking because there's only like a couple So there's 95 98 96 And then another 98. This is 98 100 98 zero zero. So let's look at it. So nine um tsmp sorry nine 96 wait That's what we actually said the package is But the package is different. I think oh nine. Sorry. This number is this nine. It's a silene ic I don't know what it means. It must be some process thing that I've got. So these are all silenes I think and then Nine six zero zero zero. So they're fixed gain no learning so Yeah, the number here Sorry, the first number is just the the um tsmp means learning nine means the chip ID And then the next number is the package and then this one has a 100 In it and Looks like that has a slightly different Automatic gain, I guess. Well, we're not going to pick the through hole one anyway. So let's pick the s and t Uh surface mount And then apply so the surface mount will have a a lower Yes, they don't have as wide of a gain. They're only good for like Two meters or so. That's okay. Um, and then Looks like there's two versions I actually tried to figure out like the real big difference between these but I like One is just a little bit smaller, but the gain is about the same Um, but the price is a little different This one is a little bit cheaper in quantity this one's I don't know they're kind of like the same thing same frequency Let's see the issue. So but they're both pretty good. Um, but I think I'm just going to go with What's interesting is also this is five meters and this says two meters But I think I'm going to go with the 96 thousand So, yeah, this looks kind of nice. I like that it runs from two to five volts and Yeah, it's a very simple carrier output. So Um, you just have to clean up the power supply and then when you get the signal out again You're going to have to do your frequency counting to figure out what the the frequency is But I think this can be interesting. So I'm going to make a breakout for one of these as well They have a vertical one nice thing about the vichy parts is they have two versions There's it's like the pins are they go around. So there's a right angle version this one that sticks out the end And a vertical version you can see that sticks up. It just depends on how it comes on the tape. Anyways, this is my Pick for the great search Hey, that's the great search All right, that's our show this week. Don't forget show until this week and also ate a box 21 Unboxing see you there. Thanks for spending your Sunday night with us everybody. Bye everybody