 Welcome to Slaydina. Hey everybody, welcome to Desk of Lady Aida. We're hacking here some hardware finding, just like little stickers on me. All right, doing some hardware here at my desk here on this lovely Sunday evening. It was really beautiful out. Don't forget folks, this Tuesday, Aida Fruit is closed because we give everybody the day off for voting. So if you want to order something and you order it on Monday, it'll ship out Monday, unless it's later in the day, it'll ship out Wednesday because again, Tuesday's a voting day and we give every Tuesday off as a phone holiday. Okay, cool. And sorry, and Veterans Day as well. So next week is a bit, we also give that day off. So next week is a little bit short. Get your hardware from us. Of course from Digikey and they'll ship it to you immediately as well. So that's the news and updates. So why don't we, you wanna go to my desk and we'll get right to it. Okay, first off, doing a lot of revisions and if you remember last week I talked about doing the revision for the 3.5 inch TFT feather wing. Here is the old version. So this version used the STMPE and had a fan 5331 boost converter, new one. You'll notice there's no gigantic diode anymore because I'm using the TPS 61129. This is part number. Sot 89 version of the boost converter. Boost converter's been working great. I've been using it a bunch of stuff. So replace the backlight driver with that. Touch screen converters now TSC2007. Also change the reset button from vertical to right angle. Same on off switch, added a STEMI QT port. Shoved everything over a little bit. Same micro SD. And now we've got this going, show the demo with the TSC2007 and it's working great. Only thing is you saw like one thing I forgot is a pull up on the backlight controller. Nope, like you need to have it activated on. So little flyway. So this is the touch screen. Hold on, let me press the reset to clean it off that little chunk there. You know, I can draw just fine. Swirls, different colors, touch screen's working great. So this hardware is good. I have to do the Pi TFTs after this. Those, I also would love to do with iSquared C but we'll see if that, I don't know if we were able to get the device to overlay working very well with the TSC 2007. So we will check it out. Okay, so this revision's done. And I'm actually like, this is gonna be my 500th revision or, you know, close to 499 or 501. You know, I think there's a couple. I might have missed one or two. A lot of revisions, you'll notice a lot of new photos on the site because, you know, pretty much every product had to be revised because, you know, a chip got discontinued or is end of line, diodes, transistors, voltage regulators. I moved almost all my voltage regulators from the AP 2-1-1-2 because I, you know, it wasn't available to the AP 2-1-2-7. So almost pretty much everything got components swapped out. But pretty much everything's worked, you know. So, you know, I had a couple, one or two items didn't make it through tests but we caught, you know, before, you know, we did a first article and we're like, oh, you know, it turns out I thought this was an okay swap but it wasn't okay swap. Yeah, revising, you know, at first it was kind of scary because there's nothing worse than revising something that you've had for 10 years because so many people are relying on it that you're like, oh no, I hope I'm not making a mistake. You know, it's a popular product. We sell thousands of them. I don't want to get this wrong. But so far, hasn't been too bad. And then, oh, you know what's funny? I have the next thing I was going to show. Hold on. It's an intermission. I'm just going to grab it over there. Okay. Are you back to the concession stand? Great. I've got the tester as I put it away because I'm going to bring it into the office for the Metro ESP32 S3 Rev-B. So, it took me just, I had a couple of weeks. I just couldn't get to it. I had to revise this before it even got really out into the store. We put it into the shop and then I realized that I was using the OPI PSRAM pins for SPI. And they were not, you can't because they're used for PSRAM. And my test, you know, when I test hardware, I test it in Arduino. And so I had enabled the PSRAM. And the PSRAM was like, yes, I'm running and I'm detected. And then later on, you know, I would in the test program, I'd have it connect to the SD card. And the test passed because after the PSRAM was initialized, I never used it. Like I tested it to see like, hey, can I communicate with you? The PSRAM said, yes, you can communicate with me. And then I never talked to the PSRAM after I configured it for the SD card. So I didn't realize that those pins were unavailable. This was like my first design with the OPI octal PSRAM Metro ESP32 S3. Learn that lesson. And then of course, you know, that when it came to the QALIA board, you know, that was good to know that those three pins were not available. I think it was like 35, 36, 37. You know, ESP, I know I love the chips, but there's always like, you really gotta watch out for those strapping pins. They expose pins that are like, hey, if you actually use this pin, like really bad things are gonna happen. And I've noticed that they've stopped doing that on modules. Like if a pin is used internally, they don't, you know, and there's really no reason for you to have access to it. They don't give you access to it, but it's, you know, lesson learned. So this version is RevB. It has that fixed. The test procedure is working and done. You know, we got a little bit of a USB waste condition, but TAC fixed it in Team USB. Another thing I noticed is unfortunately, I did a PR to update the pins for this in the expressive board support package, but then like the next day, they did a merge update with like some ESP board support package 5.1 thing and they actually ended up blowing away my changes. So I'm gonna do another PR to fix the pins because again, the old SPI pins are no longer used. They've been swapped out. Hopefully this RevB is done. There's just really all the pins. The Metro use a lot of pins. Like all the pins are used. And so it's, you know, there's no, like I had to start using pins that are normally not recommended like the SPI voltage selection pin and like the NeoPixels driven by like the debug output pin, which we don't use on this board. So, you know, I think next week, we should be able to put the Metro S3 in the shop. I really love this design. So I would love to get it into the shop. If anyone out there has a RevA, you know, we'll replace it with a RevB for free, obviously, because the RevA was like totally a mistake. Learn my lesson though. You know, what's funny is that when we had been, we tested the RevA on CircuitPython and it was hard-faulting because of the pin misusage. But because we'd been having so many weirdnesses with the S3, I was like, oh, I was like, I thought it was a different bug that I was seeing. I didn't think it was related to the OctoPSRM. Lesson learned. Okay, and then for other stuff, speaking of OctoPSRM, the Qualia board. So thanks to Melissa, we have now a touchscreen driver for the 2.1 inch. So most of the touchscreens for these large displays are CST, sorry, FT-6336U is a second very common one, or similar. Yes, this is the next rainbow demo. Of course it looks great in person. Screen through screen, screen looks a little bit flaky, but it looks really good in person. And so now, you know, when you do touch, the capacitive touch works. So thanks to Melissa who wrote that chip library for the CST-622 or something, I can't, I can't, I can't. You know, ever since we moved from printing to laser etching part numbers onto chips, it's very hard for me to read them. You have to like get them right at the correct angle. But if you have one of these screens, we now have a touch driver for it in Arduino and circuit Python. So thanks, Melissa. So the next thing I'm going to do, you know, I have a couple more sample displays, but like this board is pretty much good to go. So the next thing I'm going to do is I'm going to make a version of this for RGB 888 displays because I have a bunch of those that we stock and I want to get some nice, like IPS versions of the screens and capacitive touch and stuff. The only thing is that a lot of the RGB 888 screens don't have this nice cap touch through the main connector. They usually have like a separate little tail that has the capacitive touch. And so, and the pinout for that tail is not standard. Like this, this has a standardized, like capacitive touch is always the same pins, the RGB same pins, each sink, but the 888, the 800 by 480 rectangular displays, the 40 pin connector for the display, standard the capacitive touch, not standard. So I might start with a version that supports resistive touch because that is a standard pinout. And so I'd have a resistive touch like the TSC, you know, the TSC that I use here, this driver, I would stick this on here and use that for the resistive touch. And annoyingly, I think I still need to have the IO expander, even though I'm not using it for controlling the SPI pins to do the init code stuff, because I still need these buttons and the expander for the buttons and for the TFT reset and the TFT backlight, because it says there's so few pins available and I wanna keep all these GPIO down here. So that's okay, but you know, we're making slow and steady progress on all these displays. You know, part of it is just getting the init code going and getting the example code for everything. And then we're gonna do more with these. So that's probably the next step for this board. And then lastly, before we go into the great search, I'm back to working on my camera board, which I've been, you know, solely working on and off as parts have been available. So, WebD has moved. So I had all of these power supply components at the power supply down here, but I actually didn't make as much sense to have it down here because the things that were high current was like, you know, the backlight and the ESP. This camera just take a lot of power, but I wanted to actually keep the power supply away from it because this is temperature sensitive, which I've noticed the camera modules, you notice this one is like metal and you stick it on and I try to heat sink a little bit through the ground plane on the back. But they're, you know, they can use when it's running and like streaming the preview image, it can draw like 200 milliamps. And so I also replaced the 3.3-volt LDO with a little buck converter. And I'm using the TPS, it's the whatever the one I have in the shop, it's the TPS 629 or something, two amp like one megahertz buck converter. And it's like very cheap. It's only like 20 cents. We covered it on a previous great search for sure. And then, you know, the 1.5 and 2.8 volt regulator. But, you know, this fits underneath and then the preview screen is here. And so then I've also got a little faceplate I've designed that looks like this. So the face paint, you know, what I really like about having these SMT nuts, that you know, if you pick and place on, like they're picking placed on and there you can get to them from the front or the back. And so from this side, I use just plain machine screws. And from this side, you just add a hex nut as a spacer. And now it's, it's not screwed in. Hold on, let me see if I can, yeah, okay. You know, you can, you can screw this in. Beep, beep, beep, beep, beep, beep, beep. And it becomes a nice little faceplate. The only thing I realized after I did this is that, you know, the buttons are nice now, like they don't, you know, they stick out a little bit, but the, you can see in the middle, the speaker is a little taller than I thought. And so I'm gonna have to add a cutout for the speaker. I had little speaker holes, but I have to add an actual cutout instead. Okay, and then, so you see here. So the last thing I did is the front plate to protect the circuit tree. So like, you know, this is exposed. So I have a little front plate. And I was like, oh, let's add like a neopixel ring. I think like, you know, Phil B and I chatted about this. And we're like, oh yeah, like let's make a plate that can have a neopixel built into it. And I picked RGBW neopixels. The final version will be black. Of course, this is just green because it's fast started to get green. And, you know, I wrote a little demo that will do RGB and then white. So I don't know if I can do this. It's upside down so I can do that. Okay, so then, okay. So you can see like the color coming through a little bit. Like I'm kind of close, but, you know, I thought this could be a neat demo for the, I'm asking a lot of this camera right now. Oh, there you go. Okay, so I thought this would be neat because first off, it can act as a flash, but it also can do like some cool like rainbow ring light effects to, you know, like color, colorify whatever subject, you know, like a portraiture or like a pet or something or like, you know, but something nearby. Obviously it's can't throw the color very far, but it can, for close ups, it can do a neat color effect. And it's just like one of the things that you can't get with an iPhone camera. Like, you know, not only is it like a hackable camera, but I wanted to do something that wasn't just like, well, my iPhone can do that. So your iPhone doesn't have a ring light built in, but this one does. I mean, you can see the color effect on my face. Okay, so that's my hardware hacking for now. All right, so, this is kind of cool. You can see like this. Hold on. You can see the reflection of the ring light. Pretty bright, eight new pixels is quite bright. And I'd love that they're RGBW. The reason I went with, oh, and then of course, it's battery powered too. The reason I went with RGBW is so, you know, when you want the white light, it's extra bright and it's a pure natural white. Okay, so that's my desk. I know a lot of hardware. All right, let's go to the great search. Oh, great search for Dubai, DigiKey, and Adafruit. Thank you, DigiKey. Every single week later, user power of engineering will help you find the things that you need on digikey.com. What is a great search week? Okay, so this week, you know, one thing I look, I do before we, you know, do the show is I always look like, oh, what, you know, I search social media for like, find or search and the word Digikey and just be like, hey, somebody was like, I can't find, I'm looking for something on Digikey. And you know, some of them actually already covered, like somebody was like, oh, I need machined pens. And I was like, I already covered that. I was gonna do that as the great search, but we already did that before. But this one was kind of interesting. So I've never heard of this material before. So people who are doing like overclocking of CPUs and GPUs, you know, you need to water cool or like air cool the CPU, like, you know, the Pi five now has an air cooling add-on. And, you know, you have this cooling fan or this heat sink, whether it was water cooler. And then you have the CPU itself and you have to attach the CPU to the thing that's cooling it. And you want the thermal transmission to be as good as possible between the two. And traditionally people use thermal paste. And you know, thermal paste, I don't know if anyone, like if you've ever put together a computer, it comes in like, you know, you'd get your CPU kit, you put the CPU down and then you squeeze this stuff and you kind of like, you know, slurp it around. And then you clamp the heat sink on and like there's these little clamping bits and the paste fills in the gaps and makes like a near perfect thermal connection between the heat sink and the CPU. And so apparently there's this other kind of material called thermal pads. So I've always used paste, but I have seen thermal pads once in a while and thermal pads are, as you can imagine, very thin pieces of material and they're less messy than paste. And you never have to clean it off. You just, you stick it on and remove it. And they have a benefit of, they can also be a gap filler. Like if you don't, you know, one of the risks of clamping the heat sink onto the CPU is like, you clamp a little bit too hard, you could crack the CPU. You want it to be like exact, but like exact, no more and no less, too big, not enough thermal transfer, too little, you just like destroyed your CPU and that's really tragic. So thermal pads, you know, they have a little bit of give and the one that they're talking about in particular is called cryo sheet. And like, I have no skin in this game. I don't know anything about this product or what this is used for. So, you know, NB, notabain, I did not expert at this. But, you know, this is, you know, 15 bucks for a one inch by one inch sheet. And I was like, oh, well, I'm gonna look up and try to find the specifications for this. You know, like what is the thermal resistivity of it? And there is no published thermal resistivity. And so again, I know nothing about this market, but let me tell you as an engineer, if you're buying a product like this, that's meant for thermal heat sinking or like thermal transfer and there's no specification, they're like, you can't know if it's any good or not because it isn't like thermal resistivity isn't a feeling, it's a number. And so if the number isn't there, there's no way for you to compare it. And I think that's part of their thing is like, you know, they don't publish the number, they just say it's the best and you just sort of have to trust it. So let's show how you can find on Digikey, graphite thermal pads that do have numbers published with them and so you can actually compare them one to the other. Okay, so go to Digikey. And, you know, is it better than this other cryo thing? I don't know, but I'm gonna show you how to find the real deal. And then, you know, you can compare and contrast and do testing with it. Okay, so let's look for thermal pads. So they've got it, pads and sheets, 8,000 items. And I'll say, you know, they have like, of course, heat sinks and peltiers, you know, active coolers, water cooling, thermal paste, but pads and sheets, again, they're easy to apply. Like, you know, if you're doing, if you want to remove them, adjust them, paste is gonna probably be better because it's thinner, but just for the raw thermal transfer numbers, but there might be times you want pads and sheets. Okay, so as usual, we go to stacked and we're gonna only look for active items and then in stock, just not that there, there might be stuff, you know, that is better that's not in stock, but we only wanna see what's available. Next up, you know, I don't think we care too much about the acrylic adhesive, you know, maybe you want adhesive, maybe you don't, maybe that sounds important, but we do want is the thermal resistivity and we want to have like the lowest thermal resist, well, sorry, let's look for the thickness first because the thickness was kind of an important thing. So sheets, thighs. So these are 0.2 millimeters, thick, so let's look for about 0.2 millimeters. So if you go here, you can see, this is exactly 0.2, but let's be a little bit flexible, you know, maybe up to 0.25, maybe as low as 0.15. So we have like, you know, a range where we want thinner sheets in general. Okay, you'll notice for, if I select graphite, the thermal resistivity for graphite is gonna be the lowest ones, but let's instead of just, you know, specifying graphite, just in case there's like other materials, we're going to just go with, you know, the lower, maybe the, you know, 0.5 degrees C per watt or lower. That gets us down to 42 options. And so you'll see like, there's some very low-cost ones that are, you know, 70 cents, but these are small, they're designed for TO220. When you have like a specifically a TO220 LDO or transistor or IGBT or whatever, and you know, you don't want to like cut and drill a little hole for the, you know, the back part of a TO220 is like that nice flat metal heat sinking part. And you put that between that and the heat sink and then use a screw to connect it. And that's what that hole is for, is that's where the hole goes through, the screw goes through to clamp that transistor or LDO to your heat sink with the little pad in between. But we don't want that. We actually want like something like this because we want to be able to cut our own pieces out. Although I'll be honest, like, you know, if this is the right, you know, if the TO220 pad happens to be the right shape and you don't mind the hole or we get a version without a hole, that's fine. But let's look at larger pieces. Of the cryo sheets, you know, they do have a small 24 by 12 millimeter, but I actually think like most chips are you're gonna like a GP or CP, you're gonna want to have at least one inch by one inch, if not more. So let's in outline, let's just only pick at least, you know, one inch on one direction, but you'll notice that there's going to be a lot bigger ones. And then finally, there's a lot of marketplace options as, you know, pieces as well. So maybe we'll get rid of the marketplace, although these are, you know, you can always get these pieces if you want, those can take a little longer to ship. So let's just look at what's available in stock and looks like there's a couple options for, you know, thickness and the thermal resistivity, you know, I think we can look for the lowest resistivity. So we'll start from the bottom up. So this is the most, these are the best pads for this. This is kind of a vague one, but it looks like it's just like a gray pad. This one is pretty, it exists, these are rather large, this is 600 by 450 millimeters, but this one is fine. You know, this one even has adhesive on it. And 450 by 300 milliliters, millimeters. You compare that against, you know, these sheets that are like, you know, 20 bucks, one inch by one inch or something, this piece is, you know, $20 or, you know, or less, you get a smaller piece and you get something that's literally 100 times as large. So you can cut any size you want as many GPs or CPs as you desire. You keep this around and just cut out of it as needed any shape you want. And so this one I think is gonna be my bet. So it's a tiny bit thicker than 0.2 millimeters. It's 0.254, so it's like, you know, 0.1, 0.01 inch. So as long as it's, you know, not too thick, but again, you want it to be a tiny bit thick so it adds a little bit of the cushioning fills in the gaps. And if it's, if the clamping isn't perfectly even it will still make good contact. And it has adhesive as well, which is great. And yeah, and then there's also a data sheet if you need it. So, you know, what I like is that there's specifications for everything. They do come in different sizes and it looks like all these are graphite. Oh, one thing to watch out for graphite is it's electrically conductive. It's not isolating. So some materials that you use for heat sinking are thermally conductive but electrically isolating. Graphite is both electrical and thermally conductive. So if you look down here at the ohms it's basically zero ohms. It's basically like perfectly conductive. So make sure that, you know, it's okay if that's grounded, it's earth grounded. Make sure that it's okay for that to be touching your CPU. Some past transistors or LDOs of nodes that the heat sink is electrically connected to like the V in or the V out line, it's not ground. You really don't want to accidentally ground it to the case or something through this material. So something to watch out for. So this sheet there's also a sheet that's much thinner if you want 0.127 millimeters. This is the 462 series, 463. Both are in stock. Get a gigantic sheet and you can just cut off pieces as needed. And that's my great search. That's great search. All right, thanks everybody. That's it for this week. We'll see everybody doing the week. It's lots of videos and more ahead. Thank you so much. And don't forget to check any shipping times because we have a couple of holidays. Tuesday and Friday. Yes, thanks for the holidays. Bye everybody. Have a great week.