Hi there, as we have seen in our last session, up to now, what we have done is we have had our hands dirty on how quickly we can create a single sided PCB. So that's the PCB that we have designed and this is the board or the schematic that we have. So, this is the schematic and this is the PCB. So far, you must have now understood that the PCB design is a two step process where we first create a schematic of the circuit that we need, and then we convert it into a board file, which creates a PCB difference. So far what we have done is we have just taken all the components that are needed, and we interconnected them all like this, and then we created a board out of it. The board outlining process was first placing the components and then routing it with a desired width of the track.

Now, this approach is very much Better for smaller circuits. But when you have a larger circuit, then connecting all the wires together with each other like this, it's simply not possible. And that's why whenever we are creating any large PCBs or any large circuits or any large schematics, what we need to do is we need to build some advanced tools. And that's exactly what we are going to use in this video. So let's start. For now, let's set a target of creating a microcontroller based board.

Let's choose ATMEGA, three to eight p for our reference, and we want to create a simple bolt of ATMEGA three to eight p with all the port pins open. Now for such a kind of board, this much of the schematic is a mandatory condition because this is the power supply and after power supply, we need a microcontroller circuit. So let's see how we can do it. This is the number of components that we need. For this particular session, so the crystal, point one microfarad capacitor, then Vcc ground connectors and these are some pin stacks which are not needed. Let's remove it for now.

So that's what we need for microcontroller, you just need to search for ATMEGA three to eight p. And so that's the component list. Let's start. So here just like before, I'll either click on the Add button, or just type are typing as much comfortable for me. Now he has just like this, you have to search for ATMEGA three to eight. I chose that PD IP package because it's a gap package useful for creating a single sided PCB. Let's just place it now by chance if you have list two components like this, whether you can drag it like this and then you can use a command called delete.

This is the Delete command or the tool that you can select and just select this symbol out here. Now, if you delete or press here, nothing will happen. So, you have to precisely delete somewhere close to the symbol. Now that port has been deleted. Now let's take other components we need capacity constraint to connect over here. So just add and here between our wildcards type crystal, you will see many different crystals over here much better if you follow this and type crystal p th because we also want a printed through hole or a through hole crystal packets.

So crystal bth will give us into this sparkfun cloth library and we can choose any one as our needed. So this is a smaller Still, usually what we use is this one. So let's choose this. Then let's place it somewhere I'll just put it here. Along with the crystal, what we need are two capacitors. Those are I'll choose point one micro farad capacitors just for the package, and actually we need 22, pico farad or 33, pico farad, but the package remains the same.

So just let's stick this to capacitors. We connect them with crystal like this. And then what we do is we connect the capacitors terminals to ground. Now connecting all the pins for example, this ground pin over here then these two pins over here. Everything to this ground of the power supply is not visible or when if it is visible, it doesn't look good. And that's what we need to do is we need to add something called as net listing So in netlist thing, what we do is, we simply add some symbols, let's say, this ground symbol.

I'll place this ground symbol over here. And I'll place a Vcc symbol over here. So that's the VCC symbol. And now just connect them to wherever needed. So choose the net command for connecting them. And then from here to here, just click yesterday's options.

Now wherever you use that ground symbol, what we can do is, what we can assume is those symbols are inter connected to each other. So much better whenever taken ground symbol plays multiple of them. So some might be used here some will be used here and some might be used somewhere else. So let's shoot some more of them you can delete them further when needed. Similar thing for Vcc so sparkfun Vcc symbol Jetson externals Now let's do the net terminal and connect this wire to Crystal this capacitors this pin to the crystal again over here, then these two together and goes to ground. Yes, similarly this goes to ground over here and when it only one symbol so We need a move command for it.

So this is the move command and just drag the symbol to wherever you want your Vcc. So here I have Vcc. And here again take the net command and then connect this terminal with each other. So that does our work. Now what we need to do is we need to connect these two wires to this two points over here for the IC. So you can do it definitely like this.

But there is another way. Let's choose this way of turning the wire and the Another way is to add labels. Now these labels are required many places whenever there is a big schematic, we can just draw a part of schematic at one corner and connect it with the controller using labels, how to put labels let's take a net Have some length and just click once and then clip. Let's correct this year, then click once again and leave and then choose a tool called label and place it over here, choose another tool and place it over here. Now these are the two labels that we have connected to this to next. Now what we need to do is name those labels.

So here I'll call it x T one and let's call it x T two. Now wherever you want to connect XT one an extra two, what you need to do is simply take further to learn tables, one over here or take a net first a little bit of it and then label and then another label over here. Now with a name tool, change those labels to extreme and extreme. Now with this what happens is this is called as net listing. So what we have done is we have just added some labels, and those labels gets connected over here directly, no need to route a wire into the schematic like this and place it over here. So, that's about the session.

There's a net listing we use for Vcc ground, then crystal and then for anything that you may need So, I'm going to give you a complete schematic to finish off by giving you a PDF and a print of that particular circuit and the same thing you have to finish off. Next video will also show you how to finish that circuits. Thanks for watching.