2024 BSides Tampa PCB

hey besides Tampa 2024 we have Ramis Nixon here showing us how to plug in your extra bit for your PCB badge he's going to go through all the items in which you'll need and how to do it Rancis take it away uh hello everyone uh if you attended bsides you should have received your PCB uh attendee badge I have uh taken it apart just a little bit this is the uh little Waffle charm that goes on the front that just unplugs and I've also uh removed the battery just for today's project uh so I've got the charm here the battery here um you may have also seen at the registration table this little Hardware kit this kit comes with

an LED and a resistor that will be attached to this piece here to make it light up uh in addition to that I have just a spare little scrap piece of ethernet cable and what we're going to do with this ethernet is we're going to strip off the outer insulation so that we can get to these wires underneath that way if you don't have the small wires that are required you can use these wires instead and these are also Twisted so if you untwist these you will able to um Harvest these tiny little wires uh that you can use for this soldering project in addition to that um also have a pair of wire strippers here

I have my soldering iron and I also have some solder uh and one other tool that I have that um is optional because I'll tell you where to put everything uh but just to help out I also have a multimeter here that way I can do continuity checks to see um exactly where the uh voltage paths are for example on the back of this unit here you'll see um these tracks and these tracks are connected to these little contacts here and these contacts are where where the LED will go this circle is where the LED will go uh you can put it on the front or the back it doesn't matter as long as the

polarity is correct and this little rectangle right here is where the resistor will go and that resistor is also included in the kit here um the direction of the resistor does not does not matter all that does is slow down or decrease the uh uh the amount of voltage that is going to the led the only thing that matters is the polarity of the LED if you see right here there's a little plus sign and there's no plus sign on this side so that indicates that this is where the positive terminal will go on the LED and if you look at this led it has two legs which will later be trimmed but for now uh they remain untrimmed and

you will see that this led has two legs and one leg is slightly longer than the other that is to indicate the positive leg um LEDs short for light emitting diode and as we know in basic Electronics uh diode only allows electricity to flow in a single Direction so if you install this backwards it will not work correctly it will only work in the correct polarity so this positive leg needs to go in the positive slot before you solder it and that also needs to coincide with uh the positive and negative uh on this PCB here where the battery will be installed okay okay so the first thing we're going to focus on is this piece

here uh remember like I stated previously there is a long leg and a short leg on the E on the uh led the long leg will be your positive so we're going to go ahead and insert that with the long leg uh closer to where my finger is here so I'll go ahead and put these in the holes in the front here like so I'll just push it all the way until it's seated and then we'll double check to make sure oh I got it got it right so you got your longer leg on this side here and if you look at the board you'll see that the positive terminal is on that side as

well so now we're going to uh get a little bit of flux this is optional but it helps get my little applicator out of here okay this just helps the uh solder to flow well into the joint that you're making and I'll just uh smear a little on there it doesn't have to be pretty it just has to be on there then I'll set that back down and then we will go ahead and get our solder and the iron and be very careful with these soldering irons if you've never dealt with one before these can get up to 900° and they will burn you so hot and so fast that you won't even feel it so we will go ahead and apply a

little bit of solder to our tip here and then we will go into our first terminal touch the back side of it and apply our solder to the front until it fills that little hole just like that and we'll repeat that again on this side just like that and if you look closely you'll be able to see that there are some nice even cones where that solder has been applied and now oops and now now we will see that our LED is secured in there it's not going to be it's not going to go anywhere now so then you can just take yourself a little pair of flush Cuts here and snip off the excess just like

that and just like that now you'll see that the excess has been trimmed and now we will go ahead and move on to the resistor like I stated before the resistor is not polar sensitive so all you have to do is install it right here where this little rectangle is and where these two little holes are here and here I'm just going to apply a little bit more flux so that I have a smoother joint just a little bit there and a little bit there little goes a long way with

flux okay that's enough then we'll go ahead and install our resistor on the back side it can go on the front side as well but just to make it look a little cleaner we'll install it on the back side so we'll install one leg there and bend this over and install the other leg onto this side and then just go ahead and pull it down so that it's seated nicely onto the board I'll turn it this way so you can see it better there you go just like that and again we will apply our solder this time I will apply my solder on this side because this is the back side you always want to try to applier solder on the

back side of the joint that you're making so just go ahead and set that down I'll get my iron put a little bit on the tip here that way it makes a good contact with where you're working just go ahead and touch on the back side and apply to the front there you go nice little cone same on this side nice little conb so I'll give you a closer look here now you see that these are nice little cones of solder not too much not too little just the right amount and uh again just like before we'll go ahead and trim off this excess cut that little piece off there oops and we'll cut this little piece off

there there you have it this portion of the project is complete now we'll move on to wiring the main badge itself and see the final result all right ladies and gentlemen we have our um waffle assembly here and um I have found that the negative terminal of the LED rings to this bottom left here and I found that the resistor rings to uh this top one here so on your board uh it's going to be these left two terminals will con inside with these left two pin holes here so if we rotate everything over like that that shows us that the negative terminal on the battery tray is next to this Artemis net logo and the negative terminal for the

waffle is next to the L on the rot 13 Labs logo down here so we want to get a our jumper wires which here I've already prepared I um got some wire from uh ethernet our scrap ethernet and I've prepared these two little jumper wires and we're going to jump from emis net to this pin here at the bottom of Rott labs and then we're going to jump this top pin next to the Rott labs this is next to the r of the rot 13 Labs logo that is going to go over here to this pin uh next to this uh blue M mantis uh logo here so now I'm going to enlist the help of my lovely assistant here I'm

going to do what's called tinning the wires so I'm going to uh pre-apply some solder and uh just to make this a little safer because this iron is hot we're going to go ahead and put these in a pair of pliers here so we don't burn her fingers so she's just going to hold that just like that and I'm going to uh give that a little squeeze not too hard though and I'm going to attach or I'm going to apply some solder to the tips of these wires here that way they attach to the board easier so to do that all you do is touch the wire and then you just give it just a little bit

of solder that's all it needs and then do that again on this other side just touch it apply a little bit of solder now the wire is tinned so we will go ahead and repeat that with this other jumper here give that a little squeeze thank you very much and we will go ahead and end this wire as well so let me touch it here put a little bit of solder there and then touch it here and put a little solder there now that these wires are pre uh pre-loaded with solder it'll make it attaching to the board board a little bit easier and also it helps lock in the strands so these wires have a bunch of

little strands in them and when you tin it that keeps it from fraying so now I'm going to come down to my board here I'm just going to rotate it a little bit so that it's a little easier to see I'm going to put a little bit of solder on the tip you always want to have a little bit of solder on the tip of your iron that way it makes good contact with what you're working with so our first wire is going to go right here next to the L of the rot 13 Labs logo and we're just going to give that a little touch and it is now connected and that's how easy it is to

do you don't have to you know mess with a with a little piece of solder trying to get everything lined up when your when your contact is pre- soldered and your wire is tined so now we're going to go ahead and line up this with the uh Artemis net the the pen next to the AR Artemis net and then we're just going to give that a little touch and these uh these little wires don't need don't need a lot of heat so if you're holding your iron on there and it's not connecting or it's not not melting that means that your iron is not hot enough or you need a little more tinning on your solder and I'm not

working so let me put a little more solder and my iron here so that it makes a good connection there we go and just hold it there until it is firmed all right that jumper is now secure we're going to get our second jumper here and we're going to connect this one next to the r of the rot lab so it'll be on the top the top pin here actually let me flip this around so there's a little bit less cuz this side has a little bit less exposed wire and I'm going to go ahead and clean my tip I have a I have a gold foil tip cleaner but some people also use a damp

sponge make sure your sponge is not too wet because you don't want the cold shock to damage your iron tip all right so we're going to go ahead and touch that there and push it in till it makes a

connection okay and that is now secure and we're going to apply just a little more solder to our tip here and go ahead and connect to this lead

hold it for a second it cool down all right and now our leads are connected to the board let me go ahead and clean this up a little and then I will show it to you so as you can see let me get my my little pointer here as you can see this lower one is is connected here and this upper one is connected here now we'll go ahead and flip her over and load our battery our battery goes in to the opposite end here first and then just snaps in and by the way if you have trouble removing your battery uh at the beginning of this project all you have to do is pull back on this tab

you can do it with your finger or you can do it with a little tool like this you just pull this tab back and the battery just pops out so we'll go ahead and install our battery you'll see that we are functional here and when we connect our waffle we now have a lit waffle awesome so thank you very much for watching hope this was helpful and uh we hope you do this project if you do this project and you found a better way of doing this uh please uh don't be afraid I know most people aren't afraid to let us know in the comments and and uh attach photos as well thank you very

much and have a great night everyone good job