Good afternoon, all slight problem with the ch340 based giuliano tritho uh, usb 2 serial converter, and that is that pcb, currently have zero stock of the basic part. Ch340G. Oh dear, i can't build my charito, never mind, let's change direction and have a look for a cp2102 usb to serial converter and yeah basic part. Silicon labs, 979 of the cp2102 gmr, that's good.

Let's get started on our new project. This search facility, incidentally jlcpcb.com forward slash parts and uh - you can click this basic parts, tick box, and that only shows basic parts, which means it's very easy to narrow in on basic parts. If that's what you're after you can also tick in stock, and of course this one is - and i do have a couple of these cp2102 boards from years ago, one of them i've modified it's this one, the modification's quite subtle, though. Well.

What i mean is it's quite hard to see it's that piece of wire which i've soldered to one of the unused pins on the cp-2102 and linked it over to the reset connector. I also drilled out that, via on the underside, that's connected to reset, so that it's no longer connected to reset, there appears to be a reset pin on the cp2102 so that you can reset it externally, not sure why you'd want to do that. But what i chose to do here is to bring out, i think it's rts on this one, but i could use a dsr just as well bring that out, so that i can use that signal to reset my arduino. So here we are in easy eda.

This is the schematic, there's nothing unusual here. I have added this 4k7 pull-up on rst. You don't have to do it, but it says it improves noise immunity. I suppose the most interesting thing here is that i've put a blue led across the power rails.

Coming from the usb connector, so that's 5 volts with the 2k2 resistor and red and green leds on the tx and rx outputs. The little board i showed earlier only had the one led which they called data, but i thought i'd have both and i thought i'd go for the three different colors and here's my pcb layout, giuliano chili pepper. It's got the usb mini b with through hole pins on here, because i want to do that. First, then, i'll move on to surface mount there's the cp2102, and here is a six pin connector with five volts ground, tx rx out to label these dtr and rts.

So that's the labeling done. I did it as one continuous string, so it doesn't quite line up, but it was easier than doing six separate text fields, uh right, i'm just going to make the copper area on the top visible to check that it's uh correct and if i do a shift B, it will rebuild it anyway and then i'm also going to put a copper area on the bottom, just to save on copper being etched away. So let's do that now and so that's the copper area on the bottom. I think i've used all default settings for the copper area, just switch back to the top copper area, which looks like that i'll brighten it up by selecting the top layer.

So i think that's ready to go next thing is the bill of materials. So here's my bomb as it is at the moment now, the three leds i think i'm going to do. First. We've got blue, green and red they're all o603s, but these are just the parts that are in the ee lib, the simple library.

Now i need to make sure that i'm getting basic parts so actually back to the jlc pcb parts list and i've gone into the light emitting diodes led section. I've got my basic parts box ticked, and so what we can see here is that we've got yellow 0805 yellow 0603, whatever that is that a white o603 green 0603, some 0805 thing there's a blu-8603 here and there's a red 0603 here. So we have all the colors in oh 603 and it looks like oh 805, but i'm using 0603. So i can start picking items out of this list and transferring them into my or selecting them into my bomb.

So if i hover over the items in the bomb list, ah now you might not see those hover boxes, but basically they're the full expansion of this manufacturer part number. The blue is correct. I've written these down on a piece of paper. The green is also correct, but the red is not because this one is not a basic part, so i need to assign lcsc part and go through here.

Well, the best thing probably is to type in the part number for the red i'll try in the wrong case. Kt-0603. Ah, let's see if it can find it with the wrong case uh. Yes, it appears to have done so so i want this one led o603-r dash rd.

I know from the jlc pcb smt parts page that that is the correct part. So let's assign it to my bom. So i now know that all my leds are o603 and basic parts. So now i'm going through the resistors, i've done the 4k 7..

Let's do the 2k2 on screen. Now it's 2k 2 brings up so many resistors. It looks like it's easier to search for 2. 201, so let's do that 2.

2. 0. 1. That just doesn't seem to bring up quite so many and uh there.

We have a basic part: r0603 um, so that will do 2k 20603 assign that - and i did the exact same thing for the 4k 7.. I will do the exact same thing for the 1ks. In fact, let's do it just to make sure that it's consistent, so 1k will be 1001 1001 search and we have four basic parts and there is an o603. So, let's select that 1k 0603 1001 was my search term assign that and yes all these part numbers are very very similar.

So that's my resistors done just got to do not doing the header and i'm not having the mini usb put on. So i just need to do the 100n and the 1000 n, or one microfarad capacitors i'll go for mlcc. Well, the one microfarad 0603 basic was much harder to track down, but i've got it with a search for cl10a 105k, and here we have a one micro, farad, 603 basic part. It's um, 10, 50 volt.

So that's absolutely fine, assign that and i think we're done excellent. So that's it. I've exported bom and pick and place files. So let's now do a gerber export i'll check the connections, but i know there are problems with these four which i've not connected to anything.

That's fine! Let's ignore it this time, no keep going we'll do a drc check, no dlc errors, so we're on our way. So, let's, let's select red and um, that's about it! So now i'll go through the ordering process. Get this sent off and then that'll be back soon and we can take a look at it for the moment. Cheerio.