 Hello and welcome to another Desk of Lady Aida. It's a Sunday night. It's about Lady Aida o'clock and that means it's time to check out what's going on on my desk. I've had a sample smorgasbord and a mailbag mania going on here. Lots of stuff came in the mail so I thought I would show off what's going on on my desk like literally. Let's jump right in. Let's jump So first, I did get samples and some of them are kind of interesting so I thought I'd show them to you. This is a really long piezo sensor and these are like vibration sensors but usually they're like little disks that you vibrate but this is super long. I thought I'd try out this sample so to wire it up with a one mega ohm resistor between the two piezopads because capacitive sensor basically act as a capacitor and then the analog voltage is being read by this cutie pie and there's an LED being lit and then you can see when I when I move the sensor it detects little spikes so that it's it's like a movement motion touch sensor type thing so that's kind of interesting. That's like number one. Okay next up I wanted to show off a little demo I made because we've got audio working on the Raspberry Pi Pico in circuit python which is awesome so I've got a little speaker hooked up here and then when I press this button it makes a chime maybe I'll hold it up to the microphone. So is this Raspberry Pi Pico? Yes. It's doing audio and here's the thing. What type of audio? I'm glad you asked. So the Pico does not have a DAC. I really like DAC. Just for the folks who it's the first time they've ever seen a video. Okay well welcome to your first video. Yeah it's a digital analog converter so a lot of chips have analog digital converter they can read analog signals and some chips have a digital analog converter they can write analog signals and this is really handy when you want to do audio so some of our favorite chips like the SAMD 21 and the SAMD 51 and even like the I think the STM32 or 405 have a DAC which lets it write true analog signals so you get like a true analog output which is great for audio. The Pico does not however what the Pico does have is extremely high speed PWM it's like like 120 megahertz or something crazy fast which means that you can PWM output and then over here I have an RC filter it's a capacitor and resistor together that take that PWM signal and they smooth it out into an analog signal it's actually it's smoothed out quite well. It's not as nice as a true DAC but you know for two cents apart you get something pretty close and then it's being amplified through this little STEM a speaker thing. We also are adding I2S audio but if you want to try PWM audio that's in like the latest build for the Pico you can use any pin and then you know you don't actually need the RC filter but just look online for like PWM audio RC filter and this is I think a 1k resistor and like a 0.1 microfarad capacitor or something so check that out very fun. Like making little sound effects and then I2S audio will be even higher quality so that we can do like true like 32-bit or 16-bit audio but then you need a separate chip and it gets a little bit more complicated so that's cool though I'm glad that we have audio we also got UART recently merged in so for people who want to like talk to a GPS unit or like a fingerprint sensor other like devices that use a TTL UART check that out another one of my favorite things it just got merged in like last night is we also now have dual CDC which is like what is that it means not only do you have USB connection to the REPL but you have a separate USB serial connection just for streaming data raw data back and forth which is like super awesome. Other question? Could you do PDM for easy filtering? I don't know maybe like with the PIO and some like cool lookup tables but for now we're just using plain old PWM which which is working fine because it's like again 120 megahertz or something like super fast and as you know it's a decade above 22 kilohertz when you divide it down I think we did 10-bit PWM and it's still you know in the end the final frequency is you can do the math but it's like you know 200 kilohertz or something which means you can filter it out. Any other questions? Okay um so the dual CDC is interesting because um one of the things that I couldn't do with um circuit python until now is how to send data between a computer and a circuit python board um it's it's something that three do the Arduino because you have like control over the USB serial connection but the REPL is what takes over the serial connection on circuit python and you can't send like special characters because they actually get interpreted as like control characters or like arrow keys or like control C. The second REPL will mean that people can do like CNC projects and remote control projects and like computer to device projects so for those who've been like hey I want to send data between a computer and a circuit python board you'll be able to do that now with dual york. Okay next up I got finally um my final uh first 1000 of these funky 2x20 headers with a weird 30 degree bend you may remember this from the cyberdeck designs this is the cyberdeck uh with um OLED display on it and um you'll notice that this one has no notch and this one has a notch and you're like what's the big deal like you kind of see it like if I put my finger over it see there's like this little there's this like notchy type thing there's a little bump here there you go so against my hand you can see it so what this does I really like this notch this was like the last thing I wanted to get added if you have um something like the raspberry pi 400 um there's a little notch in the top here which again you can barely see but here there's like a matching notch and what this means is that people won't be able to plug this in offset because it's very easy to accidentally plug it in off by one um because there's nothing like this there's nothing keeping it from like being misconnected and if you've ever like had one of these you know non-notched um 2 by 20 headers you know that it's like you you have to center it perfectly and it's very annoying uh for the matrix portal um we actually used a 2 by 10 instead of a 2 by 8 header on purpose so that it would not be able to be misaligned but um with these 2 by you know because I have to stick to the 2 by 20 and 2 by 22 doesn't really exist um not the way 2 by 20 does uh which is very popular size um I just opted to get this little like notchy thing so so you can see there's a little bump at the top so that's cool which means I can send out my cyberdeck PCBs so we'll get them in soon very exciting all right so the sample smorgasbord okay and then finally I got a whole mess of samples from expressive very exciting so let's check it okay so first up ooh esp 32 s3 beta 2 chips um six of them so what's going on with these so these oh man this is like the hardest open bag so um this chip is the esp 32 f3 this is a new expressive chip um that has not only wi-fi and usb but also it's a dual corn bluetooth so it's actually more like an esp 32 with native usb it's kind of like the s2 I really like the esp 32 s2 because it has native usb it's been awesome in circuit python we're we're slowly making headway um but one of the um things that's a little annoying about it I mean just the only bit is it doesn't have the bluetooth that the esp 32 has and people love native bluetooth and it doesn't have dual core which means that there's some audio projects that and other like advanced you know machine learning or computational projects that can't run because it really needs that secondary core one core to do the wi-fi and bluetooth and one core to do um computation so the s3 solves that problem by having a dual core and um bluetooth so this will be cool so you know this is like super alpha which means your beta beta 2 so probably won't see modules for this for at least six more months but um having chips means I can desolder you know an s2 chip maybe from an existing module solder this in and then um you know we can start doing the circuit python development and testing it out in arduino I think it'll be cool because native usb dual core wi-fi bluetooth what's not to love nothing okay next up another sample I got is the esp 32 c3 okay so the c3 is totally different than the s3 even though you're like how is that it sounds the same so the c3 is the risk five core chip so this doesn't quite have native usb I think we looked into it and it has like a it has usb built in but it's a usb to the j tag and serial or something I I'm looking into it in more detail but um it's a uh risk five core with wi-fi um so this is pretty cool um this is the stuff that expressives really focusing on right now um so if you're interested in risk five and wi-fi check it out here's a hint there are some available on digikey so if you go and search for esp 32 c3 I believe some of the modules are available um these cute little modules so check it out I just got this today so like I haven't even plugged it in but um very interesting we probably won't be porting circuit python to this because again I don't believe it has like true native usb with endpoints I think it has like a predefined usb thingy thingy okay so last but not least we're gonna do all these samples oh my digikey parts came in I ordered these about a week ago so this is the esp 32 s2 fr okay what's the fr it stands for flash we're inside it has flash inside um you don't need uh an external spi flash or q-spy flash chip the q-spy flash is uh wire bonded inside the pads and there's also another chip coming out later that's also going to have two megabytes of ps ram so this is cool because it's one chip you you know it has some s ram so you can do some basic circuit python or like you know plenty of arduino stuff in the 320k um and you don't need that extra chip which means that there's some projects that I can do that I didn't mean to do um then you did so I got about I think like 50 or so of these so they look a lot like those s3 chips I mean they're just like okay I'll pick that up later let's see if I can get real close let's get small let's see if this can I can kind of see it so there you go small chip esp 32 s2 fr so built in for megabyte flash q-spy so what is it that I wanted this chip for well let's go to my computer I'll show you and then we'll roll into the great search so um I wanted to build a cutie pie with wi-fi a wi-fi cutie pie how can you not love that right so um let's just show off uh the bottom one question before we get into this does yes three have s ram I don't think so I really don't know I haven't looked into it much um so this is um the esp 32 s2 fr so you'll notice that there's no um uh q-spy flash chip now can I fit it I probably you know if it happened to be over here I might have been able to wire it up although I think it would have had to be wired up over here I mean I could probably fit it but boy I really kind of like it if I don't have to like that's just another thing I don't have to route especially when the version with s ram comes in because I wouldn't be able to fit ps ram thank you spy on this board for sure it's just it's just way too small so they've got the crystal a bunch of capacitors and then I have this idea I'm not sure if it's a good idea but like sometimes I don't have good ideas and that's okay um where so this is what the top looks like so the top has the usb-c two buttons because you need one for boot zero and one for reset um power supply a little neopixel a stem and qt connector of course and then this is the antenna so the antenna is on the top and then I'll have like maybe a wide via that goes through the pcb and then um to the antenna trace on the other side where we have like the the matching capacitors and stuff although maybe it can have like one output capacitor up here um that you know to to match the uh antenna is it gonna work I mean I usually don't do this I usually put um antennas on the same side you know I put I put them in one long straight trace but uh you know and I might still do it I do have a little bit of space on the bottom for the antenna but I thought it would better have to be antenna radiating up off the top of the pcb then on the bottom especially if it's against like a breadboard or like solder it into something you know it's like it's better to have it radiating up into free space so you know which way am I gonna go I'm not sure but while I was doing this I was uh researching some antennas and I realized that would make a really good great search how to get antennas and also showing off some of the new uh newly fangled antennas that I found while looking for antennas for this board all right the great search with digikey and ladyeata they're the ones who do this thank you digikey um ladyeata uses all her engineering skills to search the digikey site so what is this week's great search ladyeata okay I'm designing a board with the new esp 32 s2 uh which is a wi-fi chip and hold on here you go schematic checklist and um so this chip it has native uh you know wi-fi capabilities all you have to do is plug in uh you know a uh inductor and two capacitors and then an antenna um to make for very easy wi-fi connectivity um people love the esp 32 series and usually I use a module but for this design I have to go wheel small it has to fit in like you know the size of a coin it's very tiny this little board I think it's like you know one inch like point point not point eight inches by uh point seven inches so very small so don't have space for a module instead I'm going to put the raw chip on with any passive components at end antenna so I have to go and find a inexpensive surface mount antenna that's small enough to fit on this PCB so I thought let's go to digikey and start that search so it's wi-fi um so we want a uh you know wi-fi antenna and basically antennas can be tuned to different frequencies the frequencies that we want are 2.4 ish gigahertz um luckily there's a lot of people making wi-fi connected electronics and so we're not going to have to search it that hard to find it if you're doing something with like 110 megahertz or you know something that's not a standard ism band you know you're you're going to have to search a little bit harder or it might actually be easier because those options um but for us let's just search for wi-fi antenna okay so all sorts of antennas you know modules accessories um you know all this stuff well we just want the the antennas themselves obviously that search will pop up any wi-fi module that also has antennas all right let's go for active parts oh look there's us yeah um and let's look for normally stocking and uh real host compliant because that's what our minimums are um we want something that comes in uh tape and reel so not a tray or bulk and that will you know that'll cut down just so we're looking at uh components that aren't on a tray because it's there's some larger um antennas that come bulk we don't want we don't want like a duck antenna we want like a little surface mount antenna okay um next up uh there's a lot going on here so there's like so many frequency ranges and I kind of was like oh my god like what am I doing here but the first thing you want to check is like well how many bands are you going to do like wi-fi and cellular are you doing like not different protocols but different bands like bluetooth and wi-fi and zigbee and thread they're all going to be 2.4 gigahertz so you don't have to worry about that but if you're doing um you know there's some here that are like oh they do gps or cellular plus wi-fi then you'd want a multi-band antenna in our case one band is enough okay cool so we're actually pretty much you know we really drop down to um only 79 options or so which is good um so you know here's where you can go for like the gain right you know the highest gain possible but the problem is is that we're constrained by space and the larger the antenna in general the better the gain you're going to get you just have you know more space to work with when it's small you have to do like funky tricks to get it to resonate um at the the frequency that you want to um transmit at okay so let's also go for these center band frequencies so we want we want the center band about 2.4 gigahertz remember there's also five gigahertz wi-fi we're not doing that okay so far so good okay so let's look at some of the options we have here so here's some cool things so there's like pillar antennas um these are antennas that stick up or they pick in place and you put them down and they stick up out of the pcb i can't unfortunately use these um there's also a lot of like these little like you can see there's like a multi-layer like there's some sort of like multi-layer fractal antenna thing going on here just pretty cool i'm probably gonna pick up a couple different antennas to try out um we know if i look at ones like these i can kind of tell they're probably not going to fit these are longer ones um but you know anything that looks long i don't think i'm going to be able to fit because i need kind of something shortened squat um but there's antennas like this and um one thing i did you know my favorite thing is i searched by reverse stock number to see the most popular ones um these are the you know i've seen these antenna these bent metal antennas on um u blocks modules um they're apparently quite good uh and what's neat is you know they pick in place and they seat into like little holes on the pcb and they go above the pcb so you get nice uh 3d radiation um i saw a couple designs with these fractus antennas so you know the question is like well which antenna also these like these are super cool like cyberpunk like 3d molex antennas i've seen these i think um i think like the small i don't remember like the teeny tronics somebody who makes a very small electronics and and they use these antennas um but the antenna that i'm actually going to use is oh it's interesting it's not why didn't it come up hold on it is the because i actually used this part this is the 1840 founder if i let it run come on um so this is the antenna that i used on the circuit playground blue fruit so let me show that off so um if you see this little antenna here this is the same antenna it's a little tall but what i like is it's it's very compact um it's like about the same size as the 1206 resistor so this is the antenna that i'm probably going to pick up just because i already have these and again they're like they're really inexpensive they're only about 25 cents a piece um however i also want to um try out like these fractus antennas and this bolex antenna because this looks cool like this is very compact and it sticks up and especially if the price isn't um too bad so let me put down 1000 and um you can see like you know for 25 cents there's a lot of like 20 oh here it is so for like you know 25 or 30 cents there's a lot of little um nubby antennas that i can try out so the good news is that you don't have to have the exact right package on your um layout so i'm probably just going to use like the Johansson you know kind of uh hold on sort of standard um little nub antenna um footprint and then i'm trying to probably solder in different ones and then i can use this uh use a spectrum analyzer i have a little teeny one or you know what i've also done is just a distance test like i just have i just see how far away i can get um from the router before it stops working or i can measure um the rssi and just say like okay of these four bores i made which one has um the lowest rssi and that tells me which one the the antenna is working out for so there's a lot of options um try them all one thing that was uh you do have to just watch out for it's not a big deal but there's only the height the size isn't mentioned so you're going to have to use the photos and dig into the data sheet um to find the dimensions of the antenna and then you know any um uh any layout recommendations there's also like these gigantic patch antennas i mean if you want something with just like really great gain like these are awesome but they're they're going to be expensive okay so the one i ended up saying i'm going to go for is this one 24 50 80 18 v 100 there's another couple that are very similar but they're thinner this one is a little bit bigger but i've used it really successfully with all sorts of bluetooth projects so i think it'll probably work out for this wi-fi project as well but if people have suggestions for a wi-fi antenna that is really small let me know because i i've never had to make such a small wi-fi board before uh but we'll uh come back on another desk at ladiata and see how this antenna fared that's a great search okay a couple questions that came in yeah um i'll go back to the qt wi-fi pie yeah uh can you fit a quick on uh stemma on the qt pie there is one okay never mind see that now it's right um you can kind of see it in the corner i see their response their question why not a s r m connector i guess i think just for the wireless thing you're just showing like a ufl um i really want to have it be like fully compact and functional i don't want to have to have it like a separate antenna okay um if you're not using pre-sum module you need to get it fcc certified separately later yeah i will and i'll we'll we'll figure that out but you know with with express if their stuff's really good so i'm not worried about it okay uh also like wi-fi like it's it's well it's i'm not coming up with new exotic protocols it's wi-fi you know the testing procedures pretty well established uh the 3d metal antennas pi-fi you saw on the u-blocks modules are from sweden antenna company proan and then saw the pi-fi antennas on the gps prototype we're brought out to a pi fourth birthday party in cambridge okay okay uh next up i think you're just that was just okay look at that cool thing um someone was asking about eagle files look like they found they are up there is there a free eagle viewer eagle is free you can view any file for free okay so you can download the trial or whatever okay so there you go or you can import into chi-can which people do all the time import the file in the chi-cat yeah we may not have a fritzing for every single we do not have a fritzing for every single thing we have for many but not for everything yeah okay uh then this is a different maybe the antenna the next vector maker uses on his s2 feather i don't know which one it is and think of that s2 we'll go to your computer because we have that yeah this is that practice so yeah i might i might try that i mean like it looks like a pretty cool antenna um and and luckily it looks not too much bigger than um that little johansson one so yeah i might try that one out it's cool and then someone's looking for the eagle files for the uh art the pi rtc i guess they're not up um i don't know let me see we need a free pi rtc rtc for raspberry by pcb looks like we have a bird it looks like it's here yeah from june 2018 if it's not just post up in the form it's right here it's under pi rtc okay that's it okay the ds 32 31 one ds 32 31 okay it looks like oh yeah maybe that one isn't up okay i'll get that added i think we just forgot to to put it up looks like everything else is up so i'll add it tomorrow we have we have get have time okay or you can accuse us of being evil and being a closed source company that never posted a single file ever or we maybe just forgot to post it up tomorrow i mean we have like 500 different boards doesn't matter doesn't matter if you're the most certified open source hardware company even if you forget a file or sometimes people ask for files before we even have the product um we probably just forgot sorry put it up tomorrow yeah that's weird yeah i guess i forgot all right we'll add it well that's good because it means we can uh ash were certified too doesn't matter still not open source no i know but i'm saying still not pure enough not pure enough shame yeah anyways we'll um we'll post yeah we'll post up the file tomorrow you notice i'll post in our forms if we ever forget anything yeah people post the forms and then we just we just get to it okay let me switch to another question i think i got to everything high boards eventually adopted another pro ant design the niche antenna used on the zero w 3b plus and four so yeah those those are a difference you know those are like a licensed special thing and you probably need a multi-layer pcb and i'm going to try to get away with a two or you know maybe four layer for this uh qt file i think can get away with two layer everyone always tells me i can't do two layer but i always do two layer and i always get away with it okay all right and with that it's just going to get it thanks everybody thanks for tuning 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