Good morning, all this is my latest printed circuit board, which you saw in the last video. It's my radio tower i mean. Actually, in fact all it is, is a 3.3 volt regulator. Some capacitors and little blue led now that's working fine and you can see it here with the led lit up the nrf24l01 plus radio plugged into it and it in turn plugged into an arduino nano breakout board.

Now, when i was designing this, i was trying to only use uh basic components rather than extended components. The basic components are those that are already sitting in reels on the pick and place machines, and that means that if you only use basic components, no operator is required to change. Reels go and find other components and load them onto the machine, and the cost for extended using extended components is a one-off six dollars. It's not massive, but it's a challenge i think, to try and design and build something using just basic components.

Now this regulator was part of extended components. I think the 100n capacitor was as well but i've since found, because i now understand how the library works better on easy, eda um, a 3.3 volt regulator. That is a basic component. So let's go to easy eda and have a quick look at that.

So here we are in easy eda and i'm working on something new um. But let's go to the library and just have a look at these um parts and how to find the parts you need, because it's not immediately obvious, certainly wasn't obvious to me when i was making that radio tower pcb. So i've made the library really big so that we can see it now. Last time i was looking at linear voltage, regulators, and here they are they're all extended parts, and then i went to dropout regulators and these two, if i scroll all the way down, are all extended parts.

But what i missed was this more button down here now, if i click more it loads in a second set of these dropout regulators, it takes a while on this pc because it's a bit slow, still all extended parts so i'll scroll down to the bottom and Hit more once again and i'm going to keep hitting more until it's loaded, every single part in from this section called dropout regulators brackets ldo, so i've hit the more button at the bottom about five or six times and there's still another more button. So there are more regulators to load in. There are quite a lot of regulators here. What you can see now at the top is that we have a number of basic parts.

So the point is, until you bring all the parts into the list, you're not going to see all the basic parts that are available. If you list them by jlc pcb part class with the arrow pointing upwards basic parts, are at the top, and here we've got some very useful parts: we've got ht7550 five volt, i presume ht7533 that must be 3.3 volts and we've got an ams. 1117. 3.3.

Oh i'm going to have to hit that more button a few more times because i spotted um yesterday an ams one, one, one, seven five volts as well! So i'll do that now right! Well, it doesn't seem to be loading in any more parts. That might be something to do with uh my browser, but now that we know what we're looking for ams1117, we can do a search for it in this search box. I'm pretty sure i did a search for one one, one seven. So let's try that and see.

If that brings up the regulator that i was looking for and those are both extended parts now, let's try searching for ams, am s1117 and see. If i get the basic parts that i'm after and looking by part class yeah there, we have an ams 117 5.0 and an ams 1117 3.3, both basic parts, and so of course, that means that i could do this board using basic parts using an ams-1117 3.3 Volt regulator, instead of whatever this was, i can't remember what it was now, but that got me thinking and that got me searching for more basic parts, just really for the fun of it, and i found some goodies in this section: embedded, processors under atmel and avr. We have an atmega328p au and it's a basic part, because it's a microchip part now so with that atmel mic microcontroller and it's a tqfp one like this. That's the basic part and a regulator and a few capacitors and a switch.

I could build something very similar to a pro mini, but one of the parts i need is this: well, this one has a ceramic resonator, so i was looking for ceramic resonators couldn't find one in the basic parts. But what i have found is this: it's a crystal smd resonator! It's in this section, crystals smd crystal resonators um, it's a four pin resonator or crystal frequency, 25 megahertz. Now that's not ideal for arduino. We need 16 megahertz so once again scroll down to the bottom and hit more and see what comes up in the list of basic parts and after hitting the more button a couple of times.

I now have a 16 megahertz crystal. This is a yxc type and there's also a 12 megahertz and of course we need that for the ch 340 usb to serial chip there's also an eight megahertz there uh more basic parts than i thought there were, so i'm just going to click on that 16. Megahertz one to take a look at it and it should come up here on the right hand, side. Yes, there it is so it's a four pin surface mount uh crystal regulator, the crystals across pins, one and three, and if you go to the data sheet, pins two and four are marked as ground.

So that's interesting! So that's all good um we've got the 18 mega. 328 p got the crystal this one has a ceramic resonator. It's actually that little thing there. This 12 megahertz crystal here is for the ch340 on the bottom.

Can we get a ch 340 in the basic parts list so for this one i typed in ch340 and yeah basic parts, we've got the ch340g. Now the g variant requires the crystal they've also got the ch340c, which actually has a built-in crystal. Now. If i'm going to stick to my basic parts theme, then i'll need the g and i will need the crystal.

But there is a 12 megahertz crystal in basic parts and if you look around you can find leds. You can find all the capacitors you're likely to need all the commonly used ones resistors. Even these little uh four-way resistor arrays. The connect is a bit more tricky.

Um, but what i could do is leave that part off if i can't find it in basic parts and solder it on myself. Now, if you get a micro uh, sorry, no a mini b, usb connector, the slightly earlier larger type, you can get a through-hole one and uh, certainly on easy eda. There is a footprint for it, so i could cheat and just not fit that buy it and solder it in as a through hole. I could be tempted to do that or i could in fact solder in the five connections on the back here of a surface mount micro connector.

Of course, i can put this six way isp programming header in because we will need to program the uh 328p using the nano bootloader. If i'm going to go for this version, so it has occurred to me that i could build my own arduino course. I won't call it arduino. I might resurrect that name giuliano, that i came up with some time ago, which would be just a single board with an 80 mega 328p on it um i could, on the first version, move the ch340 off onto a separate board.

I've got an idea for that um, and i would then, on the board, put sockets for the nrf24l01 plus oled touch switches and possibly also sensors, because, of course, the transmitter version of this, which is out in the shed, has an si7021 temperature and humidity sensor on It i could make my own giuliano boards, with my own form factor it doesn't have to be. The uno layout, doesn't even have to be the nano layout or the pro mini i'll, come up with new ideas. So i'm going to do this um and i'm going to start here. I think i'm going to go for a little standalone ch340 board.

This is the ch340g, so it requires the crystal there. It is 12 megahertz a couple of 22 puff capacitors uh. This one has some resistors and leds so that you can see the tx and rx lights. Blinking uh this one also has a 3.3 volt input, but i don't think i'll bother with that also has an led on there.

For some reason, i shouldn't bother with that. I think that i seem to remember the data sheet, for that says just tied the 3.3 volts to one of the rails can't remember which uh through 100 n that's easy enough. This has a poly fuse on it. I might look for a poly fuse in the basic parts list.

If i can't find one, i just won't bother with it. There is a diode here and there's a tantalum and that's it. So i think i'm gon na knock up this board as a standalone usb to serial now. This is interesting because this particular connector, which i don't particularly like, because it means you've, got to plug it directly into a pc or, of course, you use a usb extension lead.

But there are some of those standalone boards with four holes laid out like that and a micro connector soldered onto them, so that might be an option or i go for my mini b with the through hole pins. I'm not sure. Yet, though those are options. So that's what i'm going to do in my next pcb video, i'm going to make a standalone ch340 usb to serial board using as far as i can all basic parts, not for any particular reason.

It's just that. I find that a rather entertaining challenge and then i've got to come up with a name. So i'm going to use this giuliano thing. I need a name for the ch340 board.

I've got an idea for that. It's going to be on a red board. I've also got an idea for a name for a nano board which will be on yellow, like this, and i've got an idea for a name for the um pro mini equivalent board, which will just be the 18 mega 328 p, but without the usb to seal Driver and that name will require it being on a green board, but more about that in subsequent videos. For now cheerio.