Good morning, all today, i'm going to continue designing my board, which is a bit like a pro mini, but only in the sense that, unlike the nano, the pro mini doesn't have a usb 2 serial converter. So you've just got a tx and rx pin on the side uh it's my board is just a stripped down microcontroller board, which has a microcontroller and not much else. So let's go back to the schematic and just see where i got to there. So here it is it's an 80 mega, 328 p micro controller.

We have a 16 megahertz ceramic resonator. There's a reset circuit here, with a switch pulling down to ground. We've got leds. This is a power led.

This is an led on d3, which i use to indicate the touch switch status. This is an led on d13. I've got links to disable those leds, if necessary. There's an isp header here to program the bootloader into this chip.

That will be essential because i doubt the chip, as supplied from jlc pcb's smt assembly service, will have a bootloader in it as a couple of headers here for my display board, oleds and touch switch and my radio tower, which is the nrf24l01 plus and here's the Serial connector, which goes over to the usb to serial converter. So that's the schematic. Now, let's take a look at the pcb well, this is as far as i've got. I've got header connectors for my radio tower for the usb to serial converter for my oled board and an isp header here.

Here's the microcontroller at 45 degrees well because you have to have your micro controller at 45 degrees, but i also put the resonator here at 45 degrees because i thought it'd be easier to connect to the microcontroller pins and that's given me an idea. It's a pretty stupid idea, but i'm going to try it and i'm going to try it now back in a moment and that is to have all the components at 45 degrees, but the headers at zero degrees yeah. Why not? Let's see if it works, it might not if it doesn't i'll undo it all, but uh, let's give it a try. Well, i've just moved a few things around and it's starting to look quite good.

I've got my led and resistor pairs. That's the power led. This is probably the d13 led. With that, being s clock i would imagine uh.

This is the d3 led a couple of uh? Oh, that's a resistor! That's a capacitor, a couple of capacitors here. I think that's the a ref one uh. What's that one? Oh! That's! The reset one yeah, that's what that goes across to the reset input: pin um ceramic resonator. There switch there yeah that all looks good, i'm gon na start wiring it up and uh, because the software is as comfortable doing 45 degree routing as a 90 degree routing.

It works pretty well, oh that didn't look very pretty. Let's try coming from this end, yeah, that's better uh! I might change that one later. In fact, let's do it now to see whether it improves i'll root it from the resonator first. Actually, i should be pressing the alt key shouldn't.

I really yeah, i think that's pretty good um, okay, so uh i've got a 5 volts here coming down to this capacitor, so yeah, i'm just going to keep going like that and see how far i get see. How many wires i need and see whether all components at 45 degrees is a good or a bad idea. So just uh three more tracks to root these two, i'm going to go on the blue side with virus and i've discovered that if you put a via on a pin like so then it assigns the signal to that via. So when you drag it off that via, i need the alt key here that, via you, won't see the pop-up, but that has the same net assignment as the pin on the chip.

I've got to fit two of these in here, which is going to be. Oh. It's not too difficult i'll put one up there and one down there, oh they're crossed over okay. I have to sort that out um.

This one here is just switch to ground. So one of these points here is ground and i think it's probably easier. If i just move it to the other side of the switch in the schematic, so if i go, let's just save the pcb and if i go back to the schematic and just move uh ground, i can have on three well, actually no ground will have to Move as well so ground can move to one and reset can move to four. I know i'll sort that out it's ugly, well i'll, sort that one out now uh.

So if i save that that just moves the uh connections onto the opposite side of the switch go back to the pcb bring in the changes, keep going, i know i've got unassigned nets. Oh there's a lot of changes there. Let's see what happens. There's a lot of crashes into the uh back into the copper area, the top ground plane.

Actually, let's just fix that shift b. Rebuilds, the copper area just want to fix all those x's yeah that looks good uh and now i can root that one top side on red from the switch to that end of this reset capacitor. Okay, that looks good, so just these two to do i'll. Do those off camera and come straight back? Okay, everything is rooted.

I'm just gon na switch the top uh copper area the ground plane to visible and see what we're looking like. Oh yeah, there's a few problems with that so shift b to rebuild that copper area. That's taken a while because my computer's doing lots of things now someone was saying: there's a way of filling in these island areas, i'll just um, try and find that and try and fill them well. It seems the solution to that is to set keep island to.

Yes, if you set it to no the areas open out um now the other thing is these spokes running into the ground points i think, are slightly too big now they're set to zero and i think that's a default, so i'm just going to set them to. Let's say 20 and see what that gives me building is taking a long time because my computer's slow and i'm running obs yeah that looks better they're. Just thinner, i mean there's no high power here, so i don't need huge spokes and it'll just cause soldering problems. If i have those really fat, spokes, um, okay, i think it's pretty much done, i might add, a copper plane onto the bottom surface, the blue surface.

Let's just switch off the red and i'll switch off the yellow as well to take a look at the blue. Let's just light that up um. Yes, i could put a copper area around that. Let's give that a try, and that looks like that with the let's select it.

If i can select it. No that's selected. The outboard outline it's quite difficult to select the uh copper area when it's the same as the board outline um, so i've reduced the spoke with, and i've said yes to the keep islands that doesn't mean that there's an island in there, which is not actually connected To anything, i don't see that as a major issue um but uh. I suppose that's why you might not not want to keep an island.

Of course, it can't fill areas like between there, where it violates the drc for track to track, spacing or trap to ground plane spacing. I suppose it is. But anyway that looks okay to me. That's the bottom layer, that's the top layer.

Let's light that up, let's switch all the layers on and uh, i'm pretty much done apart from silk screening to mark up all my uh headers, so that i know what i'm plugging to where uh. When i get the board back, so i think that's it! For the pcb design now i was going to call this the pro minty, but this is very specific to my peripherals, the radio tower sitting here and the oled and touch board sitting here. So i've just called it giuliano microcontroller, because that's essentially all it is it's a microcontroller with some leds and lots of connectors um. So that's it for this video in the next one i will assign components and uh.

This switch was an interesting choice. We'll go through that uh. The rest is actually pretty straightforward. Oh the um resonator.

Actually i think i covered that in the previous video, but we'll look at some of the components. I'll do the assignments and then get the board sent off for production. But for the moment that's it cheerio.