 Thank you very much. My name is Gavin Phantom, and I'm going to be talking to you today about hobby electronics like a pro. Now, the world of electronics has moved on quite a lot in the last few decades. And as the giant corporations who make millions or billions of electronic devices have been enjoying the progress of the last few decades, as hobbyists, we can benefit from this progress in technology as well. There are a few key differences, but the technological improvements and the process improvements are coming through to us. So what I want to talk to you today about today is if you're a hobbyist, if you're making electronics, I want to give you an overview of the kind of things that are available to us nowadays. I only have 30 minutes here, so I'm not going to be giving an in-depth tutorial on all the tools and all the processes here. I will warn you about that because otherwise we will still be here at Sundown. However, the fact that it is an overview means that if you are not a hobbyist or are not a hobbyist yet and are not into every last little detail of electronics, this is probably good for you because this means you have a chance of following along as well because you are also part of my audience and I would really like to give you an overview of how things work so that you have maybe a bit more appreciation for what goes into an electronics project when you see one. So fundamentally, at the really basic level, making a piece of electronics comes down to this. You have a bunch of components and you are trying to connect them together by wires, bits of metal that will conduct electricity. And that holds true for many hobby projects. It gets a little bit complicated when you have high frequencies involved, but let's ignore those for now. And taking that quite literally, you can end up with this. This is actually a perfectly valid construction style. It's called dead bug construction because when you take a chip and you flip it upside down with its legs pointing into the air, it looks a bit like a dead insect. It does the trick. It works. This is not my project. I found this on the internet, but there are lots of examples of these all over the place. But the one thing it doesn't have is that kind of professional look. So many hobbyists will be more familiar with this kind of stuff. Again, another picture I found on the internet. This is a piece of strip board and what you can't see but is on the other side of it is every row is connected together just with a strip of copper. And so you have this kind of thing with all the components lined up vertically connecting different rows together. And you can cut the tracks to make the circuit that you need. And this is quite a useful method of construction because you don't have to think too hard about it. You have to do a little bit of planning just to figure out where the components are going to go. But it's not something you have to plan weeks in advance. It's not something you have to have special tools for apart from a soldering iron. So a lot of people will have started out trying to make things on strip board. I've made a whole bunch of stuff on strip board myself. I'm sure some people in this room have as well. And if you're going to stick it in a box or something at the end of the day, there's no reason not to just run with it. But we can do a little bit better than that. Again, a picture I found on the internet, this is how to get started with making a circuit board that's a custom circuit board with just your circuit on it and not one that's been pre-printed in strips. And this is typically done with some sort of etrusis pen. I think this particular one was done with a Sharpie but you can spend about four times as much on a proper etrusis pen. And the idea is simple, you have a copper clad board, you draw on it with the pen, and then you dunk it in a vat of nasty chemicals and it etches away the copper that you've left alone and the stuff that you've drawn on remains. So it's a fairly simple process. But it is a bit messy if you do it this way. It relies on having good drawing skills and the intersection of people who are into electronics and people with good drawing skills is limited. So we can do one better than that. This is an ultraviolet exposure box with a transparency on it. Now what you do with this is you get a copper clad board similar to the one in the previous slide. But this one has a special photosensitive coating on it. And you put it on top of the transparency, you close the box, you expose it for a certain amount of time. And the advantage of that is that the transparency can come straight out of your laser printer. So that gets rid of the problem of having to draw lines accurately. There's still one thing that is a pain in the backside with this technique though. For most circuit boards at some point you're going to need to drill holes in it. And this is especially true for your earlier projects and for the smaller ones, where you're using traditional through-hole technology, which is where you have components with bits of wire sticking out of them. You poke them through holes and then you solder them. Somebody's got to drill the holes. And I don't know about you, but I find drilling holes accurately, especially very tiny holes in the middle of a tiny bit of copper. Quite tricky. So I've missed out quite a number of different construction techniques because that's not really the key point here. There is a technique that we can use if we do a bit of planning ahead that is becoming accessible to us. It has become accessible to us as hobbyists. And that is to get a PCB made commercially. Now in the past that's been something that has been a very expensive proposition. And, you know, for many years I discounted it as, wow, I really can't afford this, not for something that I'm just going to make a couple of and it's just going to be a project that I'm never going to use again. But the economics of this has changed. These have come down in price and it's now viable to get a small-scale project made commercially. This one is a project that I made recently and it took a couple of weeks to get it shipped over from China and it cost me probably about $20 for the boards. So if you're going to make these commercially or even if you're going to use the ultraviolet exposure method you're going to need to go somewhere, you're going to need to do a bit of preparation. Most of us have started out drawing circuit diagrams on a bit of paper and that's great because it helps you understand the circuit that you're designing. I'm not going to give you a tutorial on how to design the circuits here, by the way, the internet is full of them and I thoroughly recommend that you go and spend some time on that if that's something that you're interested in. But we can go one step up from doing it on paper. Maybe draw out a concept sketch on paper first if you want. But most of us have computers here and computers can help with this. So this is a screenshot from my laptop from yesterday with a project that I made. This is the schematic diagram for it. It's, let's say, moderately complicated for a hobby project. But it's not actually that complicated. It's got two chips that do anything substantial and a few components dotted around the place. This would be quite difficult to draw out on paper because you'd start out putting things down and then you'd realise you need to connect something from over on the left side to over on the right side and you start drawing lines all over the place and you'd be through three or four drafts before you got anywhere. So it's quite useful to have a go at using these tools. Now there's a number of different tools available. This one is an open source tool called KeyCAD. It is not the only tool available. There are commercial tools, there are open source tools with different learning curves. Most of them because they are a kind of specialist area most of them do have a bit of a learning curve but it is worth putting a bit of time in there to actually learning how to do it. Again there are loads of tutorials around for pretty much every single package out there and I thoroughly recommend if you want to have a go with one of these read some of the tutorials, they will help you a lot. So what can you do with this that you can't do with paper? Well obviously we can edit things without having to redraft it all because it's a bit neater. I find that it makes it easier to spot mistakes. If there's something not quite right I can see it more clearly on the screen than I'll be able to see it in among 30 scribbles on a piece of paper. The software can also help you out here because it can tell you you've forgotten to connect this pin to something or this power supply here isn't connected to anything are you sure you've powered your circuit? And if you're doing things with a computer one of the things that is the bain of the music industry is the fact that it is easy to copy things with a computer. It is easy to take a copy of this and put it on your website it is easy to take a copy of this and send it to your friends it is easy to put it on GitHub and open source it it is also easy to print it out multiple times it is also easy to have your designs manufactured more than once which is something that if you're drawing things out on a PCB with a pen it doesn't scale. You can use this software to draw your circuit diagrams even if you're not going to go all the way to making a printed circuit board with it even if you're going to go with a strip board or any of the other construction techniques it will help you get your circuit right before you commit to the making of it. Once you have your circuit diagram in this form you can start the job of turning it into that. Now this is a fairly messy picture because it has all of the layers of this circuit board this is the same project as in the previous slide but the software will help you get it right when you do this so you can show only limited layers so this is a two layer board it has wires on the top and wires on the bottom and it has holes which are plated so that they can connect wires from the top to the bottom they're called wires and it also has bits of writing which will come out on the finished design as a silk screen so that you know when you put it all together which component goes where it's a lot easier than if you don't have that and you just have to try and keep going back to the diagrams and the drawings. One of the key things that this kind of software will help you with is it has a thing called design rule checking the manufacturer of the printed circuit boards will have certain limits of how thin they can make the wires of how thin they can make the holes how far away they have to be from each other and the software can help you because if you tell it what the rules are it can tell you this bit doesn't comply you need to fix that or if you're really lucky just not even let you put things there in the first place so again I'm not going to go into the details on how you run this bit of software there are many bits of software this is again part of KeyCad there are many many alternatives and I thoroughly recommend you check them out as well as all of the tutorials once you have this layout done the final step with your software is to take that and export it to Gerber files these are the files that most of the manufacturers will take and pretty much all PCB software will allow you to export into this format so this is what a traditional PCB manufacturer looks like they deal with massive operations, large scales and they're not really going to talk to me or to most of you when we come along and say right I want five PCBs that are five by five centimetres this is what the factory would look like for somebody that's producing thousands, tens, hundreds of thousands large large scales and pretty large circuit boards are that the thing that has made it possible for us to do this is really twofold one is that large companies also need to do small production runs before you make a million items you want to make a small number first to make sure they work fundamentally you don't want to throw your million away when you find that they're completely broken so most PCB manufacturers will have some sort of facility for prototyping and that for a large company might mean they make 50 or 100 something like that maybe even 10 if they're a slightly smaller company now we can benefit from this the other thing that has made it possible for us to do our small hobby projects is that there are outfits out there who will take small projects from me and from you and will aggregate them onto a larger PCB and will then send them to a prototyping house they will charge a bit of a premium for this but it means that you can get your 5 small circuit boards rather than 100 big ones so this kind of PCB pooling service has really transformed the market and really made it accessible for us the other thing that has helped a bit is more on the economic side than the conceptual side this is a picture of one of the many electronics markets in Shenzhen in China and Shenzhen in particular has quite a vivid economy and an ecosystem around the small scale electronics design industry and they have a number of companies who will take really small scale designs will do the PCB pooling thing send them to their prototyping houses and are often considerably cheaper than European or American outfits so we are now at a position where you can go and send a design to a company in Shenzhen and for $10 plus a little bit for shipping and you can have 5 or 10 boards made fairly small ones but that's a lot cheaper maybe you'd be spending 30 or 40 pounds or maybe 50 pounds or something like that if you're doing it locally and one thing that I'm always surprised that people haven't heard of this when they've already been sending PCBs out to places is this website, this is PCBshopper.com I'm not affiliated with them but I have used them as a comparison site for PCB manufacturers and they will compare not just the ones in China the European ones, the American ones as well and you fill in the form, put in your requirements including whether you care how quickly they arrive they will do this for PCB manufacturer and they will also do it for assembly if you want them to put the components on the board for you I'm going to talk a bit about assembly shortly but there are services there that can do it for you as well and they will point you at the cheapest or the most reliable or the fastest whichever you want so I can definitely recommend PCBshopper.com because once you've got your designs that will find the most suitable manufacturer for you so you've used this site, you've found a manufacturer you've spent all night finalising your design the sun's coming up, you've sent off your design you go to bed, okay great, a few weeks pass and then you get a package in the post it's a very exciting day that is especially on your first time and so that one's five PCBs well it's actually six, they chucked in an extra one for free it's nice of them and so what do you do with that so you've had a few weeks to think about it gone to whichever supply you're using for your components you've ordered all the components in this case an absolute bucket load of LEDs for a little sign and it's time to start soldering them well okay that's one way you could do it if you're doing an entirely through-hole design that's what you will end up doing there are techniques for doing soldering on a large scale called wave soldering almost nobody does that at home because that involves having a vat of solder that's heated up to a few hundred degrees and having a wave travelling through it and dunking your PCB over the top of it that's a bit fiddly to set up and it's only really worth doing if you're doing large scale so through-hole designs you will be using your soldering iron such as this one if you have decided to venture into surface mount components that's components that don't put a wire through the hole they just have little bits of metal on them they're usually very small the advantage of them is that you can get so many more into the same area you'll have little bits of copper on the circuit board that are just exposed in the right place and you stick them on the surface without putting anything through the board such as this board you can solder them with a soldering iron it's a pain in the backside if you've got lots of small components you can do it relatively easy with chips there are some techniques the most common one for dealing with a chip with lots of pins is to put the solder down on the pads and then to drag the soldering iron down the row of pins when you're doing through-hole things they normally teach you to solder one thing at a time which is absolutely the right way to do it for through-hole but you do have a few techniques like this that can do things quite quickly with surface mount components but there is an easier way if you have the tools for this and that is to get some solder paste which is literally what its name implies it's a fairly thick paste of teeny tiny beads of solder with flux in them and you put a small amount on each pad there's a couple of ways of doing that one you can use a syringe it's quite difficult to get the right amount but a bit of practice will get you there and the second one is when you have your PCB made tick the box that says I would like a stencil as well it's a thin sheet of metal or sometimes capton or something else and you put it on the circuit board you line it up and you get a solder paste tool the cheap version is an old credit card and you just wipe it over and that gets you a very consistent amount of solder in all the right places and then you put it in an oven now that one might look a bit homemade that's because it is this is the one that I made for this purpose they come in all shapes and sizes you can buy them off the shelf but some of them are rather expensive if you have a large scale outfit they will have a reflow oven that is enormous and it will cost tens or hundreds of thousands for the really big ones as a hobbyist that's not really much good also you probably don't have enough space in your house for it but you can get again for prototyping purposes you can get them for a few hundred pounds as a proper reflow oven with a controller and everything I decided not to go that route I thought it would be more interesting to make my own a high street shop for 30 quid and started hacking it the critical bit about the oven the real difference between this and a domestic oven is that you have something a bit like this this is the project that I showed you the schematic of this is a controller and it measures the temperature of the oven near the circuit board and it will take it through a temperature profile that is quite important so that you can solder all your components down properly without burning anything now you can probably imagine that the results of this might come out differently from hand soldering things this is a comparison of a board that came straight out of the oven and the other board is also one that's been through the oven but it went through the oven before I'd figured out the right amount of solder paste to put on it and so I had to rework almost every single one of the LEDs now I used a solder which has a flux in it which leaves a bit of a residue so that you can see it's a bit messy and I put this side by side just to show the difference that it makes to really get the reflow process right rather than having to do it all by hand they both work they both do the job but one is let's say more professional than the other and there's one more tool which is useful if you're reworking things which is this you can get these quite cheaply from eBay, Amazon etc from Chinese sellers this is a hot air rework station despite the fancy name it is basically a stream of hot air at a temperature that you can control and at a speed that you can control so you slow it down enough you're not blowing the components all over the place and you set the temperature correctly so that you can melt the solder and not everything else these are particularly good if you have a chip with 48 pins on it or something like that and you want to melt the solder on all of them and then pick up the chip with a pair of tweezers because you're never going to get that right just going around all 48 of them with a soldering iron and hoping they haven't cooled down so I hope that's been a bit of an overview of the techniques that we've been using once you've gone through all of this you end up with maybe a finished product of sorts well it's almost finished there's one final step that you really want to do now that you've made yourself a circuit board that looks really professional you can hide it in a box this has been Hobby Electronics Like a Pro I'm Gavin Phantom thank you very much for listening