WEBVTT
00:00:00.000 --> 00:00:17.140
35C3 preroll music
00:00:17.140 --> 00:00:24.590
Herald: Our next speaker got hit by a car
really really bad and she wasn't able to
00:00:24.590 --> 00:00:32.580
do anything for around half a year. And
what do you do if you're running out of
00:00:32.580 --> 00:00:39.860
books to read and games to play. Well, if
you're already a Ph.D. in manufacturing,
00:00:39.860 --> 00:00:45.390
you probably turn around and think what
can I do in my home and what you can do in
00:00:45.390 --> 00:00:51.550
your home without many tools is actually
getting into electronics and well
00:00:51.550 --> 00:00:54.730
electronics can be functional but
electronics can also be very very
00:00:54.730 --> 00:01:00.120
beautiful. So we 're going to look at the
beautiful side of electronics today with
00:01:00.120 --> 00:01:06.575
our most excellent speaker Emily Hammes.
applause
00:01:10.595 --> 00:01:13.030
Emily: So yeah. So I'm going to talk to
00:01:13.030 --> 00:01:17.330
you guys about artistic PCB design and
fabrication. And like you said I'm a
00:01:17.330 --> 00:01:23.820
manufacturing engineer and a bioengineer.
I'm really not an electrical engineer nor
00:01:23.820 --> 00:01:30.000
am I a programmer. I literally had one
programming class in my 16 years at a
00:01:30.000 --> 00:01:35.000
university and I had two electronics
classes so really not much more than
00:01:35.000 --> 00:01:42.240
gymnasium for everybody. My first PCB that
I ever designed was actually during my
00:01:42.240 --> 00:01:47.619
Ph.D. in manufacturing. I had no idea what
I was doing so I designed it completely in
00:01:47.619 --> 00:01:53.600
solidworks which is a basically a
mechanical engineering software where I
00:01:53.600 --> 00:01:58.530
built a 3-D model and it included layers
that were going to be the copper. And then
00:01:58.530 --> 00:02:01.780
I went to an electrical engineer and I was
like so how do I turn this into a file
00:02:01.780 --> 00:02:08.060
that an electrical engineer can use and he
just laughed at me. So the purpose of that
00:02:08.060 --> 00:02:15.670
was actually that particular PCB. See if I
can get the mouse to work. Actually I can
00:02:15.670 --> 00:02:20.760
just walk over here. But basically in this
column, this column used chemical
00:02:20.760 --> 00:02:25.480
chromatography or liquid chromatography to
separate chemicals by different
00:02:25.480 --> 00:02:31.629
properties. And what I needed to do was
buffer humidity that was reaching poison
00:02:31.629 --> 00:02:39.069
gas sensors without losing the poison gas
measurements because the sensors that my
00:02:39.069 --> 00:02:43.969
colleagues were designing were cross
sensitive to humidity and to the poison
00:02:43.969 --> 00:02:48.890
gas we were measuring. So it was my job to
build a zero energy system that could
00:02:48.890 --> 00:02:52.269
remove the humidity or at least buffer it.
So the signals wouldn't reach those
00:02:52.269 --> 00:02:58.990
sensors at the same time. So what I did is
I sort of inspired by a bathtub drain as I
00:02:58.990 --> 00:03:04.590
built this PCB with the humidity and
temperature sensor in the middle and then
00:03:04.590 --> 00:03:11.469
slits in it so that the air could go
through. And that's sort of how me
00:03:11.469 --> 00:03:18.519
building holes in PCBs got started and
building holes in PCBs is not really
00:03:18.519 --> 00:03:25.680
normal for fabrication companies. So when
I took that PCB to EPFL and asked their
00:03:25.680 --> 00:03:33.120
fab to build it they were not happy with
me. So then after the accident that he
00:03:33.120 --> 00:03:40.150
mentioned I decided I wanted to, so
basically I was living with my now husband
00:03:40.150 --> 00:03:47.069
and he runs a embedded systems engineering
company. And so our apartment is a stack
00:03:47.069 --> 00:03:51.469
of oscilloscopes and multiple soldering
irons and I knew very little about how to
00:03:51.469 --> 00:03:55.379
work with these things but I was like you
know what. What you're doing is way cooler
00:03:55.379 --> 00:04:03.219
than reading books. So I'm going to figure
this out. So I started with simple things
00:04:03.219 --> 00:04:12.299
and basically then got into more complex
things. And on the far side is a image of
00:04:12.299 --> 00:04:17.168
a PCB that's taped to the window that I've
embedded plastic in I have a video online
00:04:17.168 --> 00:04:20.750
of how I did that for those, actually
those are the examples and that's the end-
00:04:20.750 --> 00:04:27.490
slide of that video. And then this is what
it looks like in the dark. So you can see
00:04:27.490 --> 00:04:32.590
that it blinks and it also has this
stained glass window property. So there
00:04:32.590 --> 00:04:41.000
just 2D art. So then this is my most
recent PCB and it's a Christmas tree and
00:04:41.000 --> 00:04:46.280
it's three dimensional. They basically the
dragon fly and the Christmas tree have the
00:04:46.280 --> 00:04:50.560
same schematic so electrically they're
identical it's just there's four of them
00:04:50.560 --> 00:04:58.150
on the Christmas tree. But mechanically
they're very different. So that's a little
00:04:58.150 --> 00:05:04.890
bit of my background and the type of PCBs
that I actually end up building. So this
00:05:04.890 --> 00:05:08.830
talk is going to be about my workflow.
It's not going to be about like all the
00:05:08.830 --> 00:05:12.700
different softwares I'll mention the
software is that I use that are free.
00:05:12.710 --> 00:05:17.610
I've used non free softwares. But those aren't
as interesting because you have to do
00:05:17.610 --> 00:05:21.500
those for a company if you want to do it
on your own. You need the free software.
00:05:21.500 --> 00:05:26.570
So I'll mention which ones I use but it's
not an introduction on how to use those.
00:05:26.570 --> 00:05:31.900
It's an introduction on how to fuse them
together. Because that's the really
00:05:31.900 --> 00:05:35.430
complicated part that I had to figure out
on my own. There's tons of youtube videos
00:05:35.430 --> 00:05:42.061
on everything else. So basically it's
mechanical design that's coupled with the
00:05:42.061 --> 00:05:46.060
electrical design. So the first thing I'm
going to talk about. It's actually an
00:05:46.060 --> 00:05:50.270
interplay between the CAD software, which
is what architects and mechanical
00:05:50.270 --> 00:05:56.810
engineers use and PCB software which is
what electrical engineers use.
00:05:56.810 --> 00:06:02.280
So basically it's not about how to use any
given software. So the first thing that I
00:06:02.280 --> 00:06:08.970
need to think about when I start designing
a PCB is what are the rules that the fab
00:06:08.970 --> 00:06:15.660
needs me to follow in order to actually
have my final electrical design called the
00:06:15.660 --> 00:06:23.490
Gerber file work in the fab or actually be
buildable and the green PCB is how it
00:06:23.490 --> 00:06:29.070
looks on KiCAD and three dimensions. The
purple PCB is how a lot of fabs would
00:06:29.070 --> 00:06:34.460
actually end up building it because a lot
of fabs do not deal with internal holes.
00:06:34.460 --> 00:06:39.810
Many of them will do it but you might have
to actually contact them and talk to a
00:06:39.810 --> 00:06:45.010
real person in order to make sure that
they will actually build it the way you
00:06:45.010 --> 00:06:51.080
wanted because their software doesn't
necessarily automatically identify the
00:06:51.080 --> 00:06:58.490
routing for that when they actually go to
the milling process. The other thing that
00:06:58.490 --> 00:07:04.030
I have to think about is what are the
design rules on V-CUTS. So a V-CUT,
00:07:04.030 --> 00:07:07.680
basically if you look at this heart that I
have an example of it's a very small
00:07:07.680 --> 00:07:13.120
heart. So I can panelize it which means
putting more than one heart on a board so
00:07:13.120 --> 00:07:17.450
that I can break them apart later. It's
makes it cheaper for me because then I get
00:07:17.450 --> 00:07:23.730
four for the same price as I'd get one for
from the fab. But I have to incorporate a
00:07:23.730 --> 00:07:28.380
way to break them apart. And those are
called V-CUTS and a V-CUT is just they
00:07:28.380 --> 00:07:36.170
basically take a blade and they run the
PCB through it and it causes a small cut
00:07:36.170 --> 00:07:41.900
to be made in the board and it's often on
both sides of the board. But in order to
00:07:41.900 --> 00:07:47.650
do that they need a flat surface so it's
difficult to see in. I'll use the pointer
00:07:47.650 --> 00:07:53.240
although I don't think it shows up online.
So basically on this red PCB where there's
00:07:53.240 --> 00:07:59.821
the four hearts, they don't have a way of
making this yellow line because, or
00:07:59.821 --> 00:08:04.580
without these small edges, because there's
no flat surface for them to use as a
00:08:04.580 --> 00:08:10.790
guide. So then I got an email back from my
fab. They are like we can't build this the
00:08:10.790 --> 00:08:15.230
way you wanted. So you have to add some
part that's flat so that we can actually
00:08:15.230 --> 00:08:20.240
manufacture this for you which is why I
ended up having to add this. So it's a
00:08:20.240 --> 00:08:22.950
really important design rule. In this case
it wasn't a problem because I had this
00:08:22.950 --> 00:08:28.620
space to make it flat. But if you don't
design it with that in mind it might not
00:08:28.620 --> 00:08:41.828
end up working. So then in order for that
extra part to be removeable I needed to do
00:08:41.828 --> 00:08:44.589
something called adding mouse bites.
There's a couple of other names that these
00:08:44.589 --> 00:08:49.949
go by but at least in Switzerland
everybody I know calls the mouse bites. So
00:08:49.949 --> 00:08:52.980
basically that's this small square. And
this is what it looks like when you zoom
00:08:52.980 --> 00:08:58.339
in and there's these small, or these three
small holes that make it very weak in that
00:08:58.339 --> 00:09:03.470
part so you can just snap it apart and
break it. And this is what they look like
00:09:03.470 --> 00:09:12.220
on the Christmas tree to break the
separate branches apart. So the other
00:09:12.220 --> 00:09:16.790
thing you need to think about. You can't
just make things infinitely thin. You're
00:09:16.790 --> 00:09:19.000
going to have to put the wires in
somewhere and you're going to have to put
00:09:19.000 --> 00:09:24.200
the components in somewhere. And so you
need to think about how big those wires
00:09:24.200 --> 00:09:32.009
need to be, how close to the edge can they
be and design with that in mind. So this
00:09:32.009 --> 00:09:36.019
is the Christmas tree that I did. And this
side is actually, it's not the mirror
00:09:36.019 --> 00:09:41.350
image. It's like the rotated image like if
you flip a pancake over a turn a book
00:09:41.350 --> 00:09:51.199
over. So this is the backside and this is
the front side of each other. So when I go
00:09:51.199 --> 00:09:55.600
and I zoom in on the center what you're
seeing is actually this is the backside
00:09:55.600 --> 00:10:00.269
that would be on here. This is the
backside that would be over here. And what
00:10:00.269 --> 00:10:05.180
you can see is that up here it's really
really tight and so you have to think
00:10:05.180 --> 00:10:12.470
about how many wires do I kind of expect.
How big are these components and design so
00:10:12.470 --> 00:10:17.480
that it really will eventually fit. And
sometimes you have to redesign things
00:10:17.480 --> 00:10:24.820
because you need more wires than you
originally thought about. And then there's
00:10:24.820 --> 00:10:29.529
also mechanical properties. So PCBs come
in different thicknesses in the case of my
00:10:29.529 --> 00:10:34.980
Ph.D. when I built this I needed a very
very thin PCB because I had a very tight
00:10:34.980 --> 00:10:41.500
restriction on this component and actually
all of these measurements are minimized as
00:10:41.500 --> 00:10:48.400
much as possible for clearance and
manufacturability incivility. So in this
00:10:48.400 --> 00:10:52.750
case the PCB was really really stable once
it was in the column.
00:10:52.750 --> 00:10:55.695
But a number of people were not careful
and my collaborators...
00:10:55.695 --> 00:10:57.820
Because this was delivered all over the
European Union.
00:10:57.820 --> 00:11:01.430
A number of my collaborators were not
very careful with this PCB
00:11:01.430 --> 00:11:05.960
and they would bend it or break it, which
made my fab even more happy with me
00:11:05.960 --> 00:11:13.579
because basically they kept having
to rebuild them. So, you just need to
00:11:13.579 --> 00:11:17.790
think about the manufacturability and like
once you start removing the inside how
00:11:17.790 --> 00:11:22.089
strong will it be and will I be able to
bend it like paper. Because if you can do
00:11:22.089 --> 00:11:30.529
that, it's not going to last very long. So
then you also just need to think about the
00:11:30.529 --> 00:11:37.779
tolerances. And a lot of these are online.
So for example holes in pin headers. I
00:11:37.779 --> 00:11:43.610
recently had a PCB that I designed and the
pin headers were a really good tight fit.
00:11:43.610 --> 00:11:48.029
They basically stuck them in and they were
pretty much a right angle in the first
00:11:48.029 --> 00:11:55.689
round. And then I ordered more and the
holes didn't fit anymore. So you need to
00:11:55.689 --> 00:12:03.869
always allow for, you know, some tolerance
in your manufacturing site an error on a
00:12:03.869 --> 00:12:09.920
bigger hole that you fill in with solder
at least in the artistic side then a small
00:12:09.920 --> 00:12:16.829
hole that you have a perfect fit with.
Also wires near the edges can sometimes
00:12:16.829 --> 00:12:23.939
cause problems. And that happens because
the tool might not be perfectly aligned.
00:12:23.939 --> 00:12:28.139
So if you put your wires further away from
the edge you're going to have a more
00:12:28.139 --> 00:12:32.999
likely chance of having a lot of really
good PCBs rather than difficulty with your
00:12:32.999 --> 00:12:38.269
fab. And if you're already asking your fab
to do special stuff for you, you probably
00:12:38.269 --> 00:12:47.220
don't want to make their life even harder.
And then tool radius. So in this first
00:12:47.220 --> 00:12:53.879
version of the dragon fly I sometimes had
problems with this particular joint and
00:12:53.879 --> 00:12:58.339
you can kind of see a blown up sort of out
of focus image here where you can see that
00:12:58.339 --> 00:13:02.249
they had trouble with the tool because
they were using one milling tool for this
00:13:02.249 --> 00:13:06.850
outside part. And then they had to go in
with a smaller tool to sort of get this
00:13:06.850 --> 00:13:12.329
part out. And it was difficult for them.
So that's why in the Christmas tree I made
00:13:12.329 --> 00:13:18.399
the fillet, so that's the curves on the
inner fillet, in manufacturing or and
00:13:18.399 --> 00:13:23.580
mechanical engineering is when you have a
tight joint and you make a small radius
00:13:23.580 --> 00:13:29.839
that's the size of the tool bit or larger.
So I made bigger ones in later designs,
00:13:29.839 --> 00:13:37.129
for that reason. So now that you kind of
have a background in all the different
00:13:37.129 --> 00:13:40.800
things you have to keep in the back of
your mind when you're actually going to
00:13:40.800 --> 00:13:47.050
try and have this fabricated. Now, I'm
going to get to my workflow, which is what
00:13:47.050 --> 00:13:51.949
I actually go through when I'm trying to
design something new. So the first thing I
00:13:51.949 --> 00:13:55.860
do is I actually get a piece of paper and
a pen and I just start sketching what I
00:13:55.860 --> 00:13:59.929
think it's going to look like. It's so
much faster to draw in on paper, even
00:13:59.929 --> 00:14:05.439
though I'm really not a great artist, than
it is to try and draw in CAD with exact
00:14:05.439 --> 00:14:12.009
dimensions and so on. Then I make a
schematic in KiCad. Schematics are
00:14:12.009 --> 00:14:16.190
basically the the electronics, and saying
you know I need a resistor, I need a
00:14:16.190 --> 00:14:22.060
capacitor and so on. Then I pick the
components, so that's like not just I need
00:14:22.060 --> 00:14:26.360
a capacitor, but I need this type of
capacitor, that's this big, and this wide,
00:14:26.360 --> 00:14:33.759
and this tall. And then, once I have that,
I now have the maximum size that all my
00:14:33.759 --> 00:14:38.519
parts need to be, that need to fit on the
board to actually do something. So then I
00:14:38.519 --> 00:14:43.839
can go in to a CAD model, which is what
the mechanical engineers, and the
00:14:43.839 --> 00:14:48.559
manufacturing engineers, and the civil
engineers, and the architects use, to
00:14:48.559 --> 00:14:56.709
start building the PCB outline, so that
electrical circuit board outline. Then I
00:14:56.709 --> 00:15:03.939
import that model and I use the outlines
that I drew as the edge cuts. So that's
00:15:03.939 --> 00:15:11.610
actually the end of where the milling tool
will go during the manufacturing process.
00:15:11.610 --> 00:15:19.399
And then I placed the components where I
want them to be. And then I connect all
00:15:19.399 --> 00:15:26.100
the wires how they need to be. And then I
optionally will panelize them, depending
00:15:26.100 --> 00:15:29.250
on how big that PCB is going to be. So
that means putting more than one of the
00:15:29.250 --> 00:15:34.300
same thing on the same board. And then ,if
I need to in order to have it be
00:15:34.300 --> 00:15:39.410
manufacturable just like the heart, then I
have to add breakoffs, which is all those
00:15:39.410 --> 00:15:46.269
parts that I'll eventually throw away just
so that they can do v-cuts and so on. So
00:15:46.269 --> 00:15:54.100
this is me sketching what I think my
Christmas tree will look like. So what I
00:15:54.100 --> 00:15:57.310
did as I started and I literally got a
piece of paper and I started drawing
00:15:57.310 --> 00:16:04.389
triangles, that are the size I wanted it
to be. So this is 10 centimetres tall and
00:16:04.389 --> 00:16:11.459
then each one of those small triangles is
5 centimetres. And then I started sort of
00:16:11.459 --> 00:16:15.799
sketching this, trying to keep it at about
3 millimetres, because I've done so many
00:16:15.799 --> 00:16:23.079
charlieplexing LED things at this point, I
know that if it's less than 3 millimetres,
00:16:23.079 --> 00:16:27.839
it's going to be hard to route a lot of
wires. So it's a good starting point from
00:16:27.839 --> 00:16:33.290
my side. All my components I also know
will be able to fit on that 3 millimetres,
00:16:33.290 --> 00:16:36.410
except the microcontroller. So that means
somewhere I'm going to have to make
00:16:36.410 --> 00:16:42.069
something bigger than that 3 centimetres
or 3 millimetre, 3 centimetres, sorry
00:16:42.069 --> 00:16:47.829
that's wrong. It should be centimetres,
not millimetres. No, it should, yes
00:16:47.829 --> 00:16:54.619
millimetres, sorry. Sometimes I think in
inches, I'm American. Laughs I haven't
00:16:54.619 --> 00:17:00.999
quite converted. So basically I also think
about what it should do electrically. So
00:17:00.999 --> 00:17:04.929
is this blinky lights, is there a motor is
there, what's that going to have on it?
00:17:04.929 --> 00:17:09.280
And is it going to be 2D or 3D? And I
start thinking about if it's 3D, how am I
00:17:09.280 --> 00:17:13.829
going to get ground and five volts from
one side to another. Do I need to get a
00:17:13.829 --> 00:17:17.589
signal somewhere? Like is there one
microcontroller on this 3D object, and
00:17:17.589 --> 00:17:23.040
therefore the branches are of the
Christmas tree are all going to have to
00:17:23.040 --> 00:17:26.550
get the all the signals from the
microcontroller or I'm going to have
00:17:26.550 --> 00:17:33.920
separate microcontrollers on each branch?
How's that gonna work? Then this is the
00:17:33.920 --> 00:17:37.740
schematic, actually, and it's the same
schematic I've used for the dragon fly,
00:17:37.740 --> 00:17:45.120
the heart, and the Christmas tree, where I
basically go in and I say "Okay, I have
00:17:45.120 --> 00:17:49.180
that sketch that I drew by hand and I'm
going to need a capacitor that goes
00:17:49.180 --> 00:17:52.110
between five volts and ground. I'm going
to need the microcontroller that's going
00:17:52.110 --> 00:17:56.271
to tell all these LEDs what to do. And
because these are LEDs, I'm going to need
00:17:56.271 --> 00:18:01.840
resistors." So I connect them all the way
that I want them to be and the way they
00:18:01.840 --> 00:18:08.130
need to be to work. And then the next
thing I do is I actually go through and I
00:18:08.130 --> 00:18:14.110
get on like a distributor for electronics
and I actually pick components. So this is
00:18:14.110 --> 00:18:21.550
in 0603 capacitor. These are taken from
DigiKey. This is an ATtiny, these are
00:18:21.550 --> 00:18:26.550
resistors, this is the LED and so on. And
that way, I have a physical idea of how
00:18:26.550 --> 00:18:33.200
big these things need to be. And then
again footprints, so the pads that those
00:18:33.200 --> 00:18:36.540
components are going to be soldered on are
actually bigger than the components
00:18:36.540 --> 00:18:42.940
itself, logical. So I need to figure out
exactly how big those need to be. Because
00:18:42.940 --> 00:18:45.610
if it's a perfect fit for the resistor
somewhere, that means that's not going to
00:18:45.610 --> 00:18:49.760
be a perfect fit for the, resistor, it's
not going to be a perfect fit for the
00:18:49.760 --> 00:18:55.390
pads. So I need to really think about the
pads. And at this point sometimes I design
00:18:55.390 --> 00:19:02.630
new footprints. So maybe I want, instead
of the resistor to look like this, maybe I
00:19:02.630 --> 00:19:08.610
want it to be a Christmas tree. So the
ball needs to be actually a ball, like I
00:19:08.610 --> 00:19:12.930
want these to be the ornaments. So then I
just would make some silkscreen marks
00:19:12.930 --> 00:19:21.050
around it to make it look like a ball, for
example. So then, I have to go ahead and
00:19:21.050 --> 00:19:28.640
actually build the CAD model. So that
means I go into Fusion360, you could use
00:19:28.640 --> 00:19:32.840
other software, I've used SolidWorks
before, as well. And then I start drawing
00:19:32.840 --> 00:19:39.630
things. And these are all 3 millimeters.
And this is actually where the micro
00:19:39.630 --> 00:19:43.760
controller goes, because it has to be big
enough for the microcontroller. And so
00:19:43.760 --> 00:19:48.370
this was the logical place to put it. In
the dragonfly it's actually in the center
00:19:48.370 --> 00:19:54.190
where the wings come together. In the
snowflake it's in the center as well. In
00:19:54.190 --> 00:19:57.800
some other PCBs that might be on the stem
of a shamrock, because those are logical
00:19:57.800 --> 00:20:04.800
places to be bigger. So this is a
snowflake that I was talking about. So
00:20:04.800 --> 00:20:08.871
sometimes I also, and this is like
actually the one of my earlier PCBs, I
00:20:08.871 --> 00:20:12.440
actually modeled the components to make
sure that it would make sense and it would
00:20:12.440 --> 00:20:19.350
look OK. And I don't have the back shown.
But I also modeled this component. And if
00:20:19.350 --> 00:20:23.740
you look, it's kind of a tight squeeze
there and I needed to make sure it would
00:20:23.740 --> 00:20:31.920
fit. So then, once you have a CAD model
that you're happy with, then this is sort
00:20:31.920 --> 00:20:36.230
of a weird step that it took me a while to
figure out. But I already had a lot of
00:20:36.230 --> 00:20:44.229
experience dealing with the quirkiness of
machining tools and 3D software.
00:20:44.229 --> 00:20:50.370
So, basically I export it from Fusion360
as a DXF, but because there's multiple
00:20:50.370 --> 00:20:57.370
different formats that DXF can have, DXF
is just a two dimensional drawing format -
00:20:57.370 --> 00:21:01.350
there's multiple forms that it can have -
I actually have to open it in another
00:21:01.350 --> 00:21:06.000
software, because Fusion360 doesn't save
it in a format that KiCad can read. I open
00:21:06.000 --> 00:21:09.850
it in a different free software and then
just save it as an R12 ASCII file, that's
00:21:09.850 --> 00:21:15.440
a form of DXF, and then I can open it in
KiCad. If I don't do that what ends up
00:21:15.440 --> 00:21:20.800
happening is only the straight lines show
up and some of the circles might. But none
00:21:20.800 --> 00:21:28.050
of these complicated curves will show up
as edge cuts. So then I just go through,
00:21:28.050 --> 00:21:33.261
once I have the edge cuts put on my board.
Because this is when I'm starting to
00:21:33.261 --> 00:21:40.140
actually design the board. I import all of
the LEDs and so on that I did and the
00:21:40.140 --> 00:21:44.550
schematic, and then I start placing them
where I want them to go. In some cases, I
00:21:44.550 --> 00:21:48.940
might have, if I'm really going to be very
specific about where an LED needs to be, I
00:21:48.940 --> 00:21:56.190
wasn't so much on the Christmas tree, I'll
also have exported the LEDs as part of the
00:21:56.190 --> 00:22:01.260
edge cuts and I'll just delete them later.
And that way I know exactly where I want
00:22:01.260 --> 00:22:08.650
that LED to be. And then I need to route
them. So all electrical softwares have
00:22:08.650 --> 00:22:13.430
routing, as far as I know, that you can do
and it usually comes out in like a 45
00:22:13.430 --> 00:22:23.150
degree angle or maybe 30. So often, I will
do it by hand. This is a different kit
00:22:23.150 --> 00:22:27.760
that I built and I wanted the routing to
sort of make a heart shape in the
00:22:27.760 --> 00:22:36.600
charlieplexed heart. And so I did it by
hand. The other option, it also if you do
00:22:36.600 --> 00:22:41.410
it by hand, you are less likely to make
really dumb mistakes. So for example when
00:22:41.410 --> 00:22:45.780
you use an auto router, auto routers know
where the components are, but they really
00:22:45.780 --> 00:22:52.250
don't care about anything you would learn
in like a physics class. So they have no
00:22:52.250 --> 00:22:57.290
problem with making an insanely long line
from a capacitor to a microcontroller and
00:22:57.290 --> 00:23:04.100
you want that line to be really really
short because it's supposed to buffer
00:23:04.100 --> 00:23:09.350
voltage changes and provide, like,
basically buffer fluctuations in the
00:23:09.350 --> 00:23:15.270
amount of energy that microcontroller is
receiving from the main power source.
00:23:15.270 --> 00:23:22.480
Because maybe more LEDs are drawing more
energy. But anyway, it'll make those lines
00:23:22.480 --> 00:23:28.530
not the way they should be. So doing it by
hand is often better, but with some of my
00:23:28.530 --> 00:23:34.260
designs like the Christmas tree it's just
not possible. Because this isn't an angle
00:23:34.260 --> 00:23:40.490
that KiCad can do and that most software
can do, I actually export the file that
00:23:40.490 --> 00:23:49.830
has all of the components on it, placed in
the correct location and the edge cuts,
00:23:49.830 --> 00:23:55.240
and TopoR will go through it and it will
make curvy lines, by making lots of tiny
00:23:55.240 --> 00:24:02.020
straight line segments. And one problem
with that is that, a lot of these auto
00:24:02.020 --> 00:24:06.400
routing softwares have no ability to work
with a giant hole in the middle of the
00:24:06.400 --> 00:24:12.520
PCB, so they'll just connect like this to
that, just through the hole. So that
00:24:12.520 --> 00:24:17.090
doesn't work either. So there's a script
on my GitHub page. It's actually not on
00:24:17.090 --> 00:24:21.560
there right now. I will put it up there by
the end of Congress. But I just didn't
00:24:21.560 --> 00:24:27.750
have time over the holidays. And then once
I do that, I also need to check for stupid
00:24:27.750 --> 00:24:32.490
electrical errors. Not because they won't
be connected but because sometimes you
00:24:32.490 --> 00:24:35.930
have components that are close to another
component and the lines need to be very,
00:24:35.930 --> 00:24:43.110
very short. So you might have to fix that
on your own. So then at that point you're
00:24:43.110 --> 00:24:47.210
basically done, except if you want to
panelize. So in the case of the Christmas
00:24:47.210 --> 00:24:56.120
tree I had 1 and I wanted to make 4. So in
order to make it panelize well, because
00:24:56.120 --> 00:25:01.120
this is basically just a triangle, and I
needed to know how long it was and how
00:25:01.120 --> 00:25:06.750
tall it was. And in my mind it was the
full 5 centimeters, but in reality,
00:25:06.750 --> 00:25:11.890
because I had cut off this corner, it
wasn't five centimeters. So I took a like
00:25:11.890 --> 00:25:15.200
marking edge, so something that the
manufacturing process doesn't use for
00:25:15.200 --> 00:25:20.530
anything, and it doesn't end up in the
Gerber files, and I extended this line out
00:25:20.530 --> 00:25:25.910
to where it should have ended. So it would
be the right shape. So then I could rotate
00:25:25.910 --> 00:25:34.940
it and flip it and so on and have it
turned into this pattern. The other thing
00:25:34.940 --> 00:25:39.190
is that I had to remove extra and
duplicate lines. So in the process of
00:25:39.190 --> 00:25:44.560
making one, I needed to close all of the
lines. So on this mousebite there's a line
00:25:44.560 --> 00:25:49.750
here, that actually, the arrows will show
it. So the blue lines or the blue arrows
00:25:49.750 --> 00:25:54.520
show where these mouse bites are closed
and they're actually going to flip and
00:25:54.520 --> 00:25:59.960
connect to each other. So I had to remove
them in the final panelized version over
00:25:59.960 --> 00:26:05.362
here. So you can see it four times with
this edge removed. And then there were a
00:26:05.362 --> 00:26:08.730
couple of mousebites that were close to
that edge so they weren't completely
00:26:08.730 --> 00:26:11.620
closed. And it also had problems with
that, so I had to just replace them with
00:26:11.620 --> 00:26:18.580
circles or close them manually. And then
the next step when you're panelizing is
00:26:18.580 --> 00:26:23.800
also to add brake offs for the
manufacturing process. So in this case
00:26:23.800 --> 00:26:31.730
that was these small edges because the
v-cuts needed the flat surface. So that is
00:26:31.730 --> 00:26:37.160
the end of my talk. And if you have
questions, I'm open to questions. You can
00:26:37.160 --> 00:26:39.660
also, if you're online and you're watching
this later, you can leave a comment on my
00:26:39.660 --> 00:26:43.280
YouTube channel. I try and get back to
people and make videos based on their
00:26:43.280 --> 00:26:48.160
comments. I have a Tindie page and I have
a webpage. And then, if you want to learn
00:26:48.160 --> 00:26:52.300
how to solder but you don't know how, come
over to the hardware hacking area because
00:26:52.300 --> 00:26:54.680
I'm going to be teaching a workshop on
that.
00:26:54.680 --> 00:27:03.600
Herald: Thank you very much for this most
excellent talk. If you have, please a
00:27:03.600 --> 00:27:10.030
round of applause.
Applause
00:27:10.030 --> 00:27:14.290
If you have any questions, thers
microphones, 6, distributed through the
00:27:14.290 --> 00:27:19.330
room. Please just walk up to them and I'll
point you out. Are there any questions
00:27:19.330 --> 00:27:24.650
from the internet? No questions from the
internet. Are there any questions from the
00:27:24.650 --> 00:27:32.730
audience in the Saal? Come on guys, I know
it's early. There is one. Please walk up
00:27:32.730 --> 00:27:39.690
to the microphone there in the aisle.
Center front microphone please.
00:27:39.690 --> 00:27:45.630
Front center microphone: Let's see if this
works. Sounds good. So I'm also very
00:27:45.630 --> 00:27:49.690
fascinated of the idea of charlieplexed
circuits, and I'm wondering: Do you sell
00:27:49.690 --> 00:27:53.810
any of your PCBs as kits or something?
Emily: Yeah, I have all of them as kits
00:27:53.810 --> 00:27:56.200
with me. So go over to the hardware
hacking area.
00:27:56.200 --> 00:28:00.430
Mic: OK, thats cool, thank you.
Emily: Yeah, even the ones that aren't on
00:28:00.430 --> 00:28:05.000
Tindie. So basically anyting on my
webpage, tried to get all of it here.
00:28:05.000 --> 00:28:08.610
Herald: Again, center front microphone
please.
00:28:08.610 --> 00:28:14.870
Question: Yeah, hi. Why didn't you use the
PCB layout software to create the outline.
00:28:14.870 --> 00:28:23.261
Emily: Because KiCad doesn't like
splines. And so, if i did the, so
00:28:23.261 --> 00:28:29.280
basically PCB software is often designed
for straight lines or arcs. So just
00:28:29.280 --> 00:28:35.660
circles und straight lines. To define more
complex shapes is significantly harder.
00:28:35.660 --> 00:28:41.040
Also, with like standard manufacturing
software or standard mechanic engeineering
00:28:41.040 --> 00:28:45.900
software. they are designed so that you
can parameterize things. So actually with
00:28:45.900 --> 00:28:52.590
the snowflake or the Christmas tree in the
Fusion360 version, I have numbers that
00:28:52.590 --> 00:28:58.520
say, you know, 3 milimeters. This is three
milimeters. So if I decide later I need it
00:28:58.520 --> 00:29:05.820
to be 4 milimeters, I just go 4 and then
export it again. It's much faster. It
00:29:05.820 --> 00:29:08.145
sounds harder, but is much faster.
00:29:08.145 --> 00:29:10.370
Herald: Again front center microphone
please.
00:29:10.370 --> 00:29:21.060
Question: Absolutely newbie. So I'm only
wondering if you prefer EAGLE as well?
00:29:21.060 --> 00:29:25.570
Emily: So I've never used EAGLE.
And the reason, that I haven't is...
00:29:25.570 --> 00:29:30.680
Well, there's two reasons.
First, right now it's only free
00:29:30.680 --> 00:29:35.190
for smaller PCBs than the Christmas tree.
So I don't want to spend money because I'm
00:29:35.190 --> 00:29:40.860
currently unemployed and I don't have that
kind of money. Second, my husband runs an
00:29:40.860 --> 00:29:45.050
embedded systems company and he uses
KiCad. So I have a professional that lives
00:29:45.050 --> 00:29:48.960
with me and that I can go "I don't
understand." and he can be like "Here is
00:29:48.960 --> 00:29:53.310
how it works." So on that side it was
easier for me to use the software that was
00:29:53.310 --> 00:29:57.650
already in my house. When I was working
professionally, we used a professional
00:29:57.650 --> 00:30:02.550
software. So it's just basically I started
learning when EAGLE went from open source
00:30:02.550 --> 00:30:08.970
and free to being bought by Autodesk.
Applause
00:30:08.970 --> 00:30:12.960
Herald: Again center front microphone
please.
00:30:12.960 --> 00:30:16.620
Question: Thanks for this interesting
talk. So I knew about PCB design, but the
00:30:16.620 --> 00:30:23.050
artistic part is new. My question is, how
do you deal with, so I like to use Git or
00:30:23.050 --> 00:30:28.460
some version control and with KiCad it's
easy. You have it if it's a XML file. But
00:30:28.460 --> 00:30:33.690
with outer tools you have binary files. Do
you have any way to deal with diffs of
00:30:33.690 --> 00:30:40.750
binary files?
Emily: So with most mechanical software
00:30:40.750 --> 00:30:46.720
there is version control as well. So you,
like, for example in Fusion360 every time
00:30:46.720 --> 00:30:52.800
I save it'll save the same file as version
1 or version 2 or version 3 or version 4.
00:30:52.800 --> 00:30:58.560
So it't not really GitHub, but it does have
a way to regress backward in what you
00:30:58.560 --> 00:31:00.560
want.
Mic: So you save it as version 1, version
00:31:00.560 --> 00:31:03.280
2 or does it automatically
Emily: It automatically actually does it.
00:31:03.280 --> 00:31:09.680
Every time you save it, it sort of appends
a new version to it. Because this is also
00:31:09.680 --> 00:31:15.150
a problem industrially with mechanical
engineering designs, where mutlipe people
00:31:15.150 --> 00:31:21.250
need to be working towards getting maybe a
probe to be stable. So they also have to
00:31:21.250 --> 00:31:24.780
deal with version control.
Mic: Because I'm trying to do the switch
00:31:24.780 --> 00:31:30.400
from EAGLE to KiCad, and in EAGLE I just
have version 1, version 200, 300, 400
00:31:30.400 --> 00:31:40.760
Emily: Yeah, with KiCad I don't really do
so much version control. Yeah. I, he would
00:31:40.760 --> 00:31:45.160
be the person to ask, because he's the
professional. The guy in that shirt with
00:31:45.160 --> 00:31:50.140
the "do not panic" is really the person I end
up asking all of my really tough
00:31:50.140 --> 00:31:54.500
electrical questions, too.
Herald: We have another question on the
00:31:54.500 --> 00:31:58.650
front right microphone.
Mic: Yes, hi everybody. Thanks for the
00:31:58.650 --> 00:32:03.460
talk. Not really a question, but just a
heads up. There is going to be, according
00:32:03.460 --> 00:32:11.320
to my knowledge, a KiCad beginner
workshop on friday at 9 in the evening.
00:32:11.320 --> 00:32:14.450
Just for those interested.
Emily: Cool.
00:32:14.450 --> 00:32:17.430
Mic: Maybe you show up as well.
Laughter Emily: Maybe
00:32:17.430 --> 00:32:20.461
Herald: Another question form the cernter
front microphone.
00:32:20.461 --> 00:32:25.770
Question: To the usual PCB interested
person, how would you recommend
00:32:25.770 --> 00:32:33.300
to find and select a fab?
Emily: For regular PCB, like if you are
00:32:33.300 --> 00:32:39.880
just trying to make a square, I think any
of them will probably work. For me, like
00:32:39.880 --> 00:32:44.840
when I was trying to do the Christmas
tree, I sent it to 3 different fabs. And
00:32:44.840 --> 00:32:49.500
one of them I have a contact there,
because I actually visited that fab at one
00:32:49.500 --> 00:32:57.630
point. And so that worked out. But when I,
acually the purple picture is from
00:32:57.630 --> 00:33:03.900
OSH Park, and they say somewhere, that
they don't deal with internal holes.
00:33:03.900 --> 00:33:12.120
Yeah, so I would just contact people. Just
email people if you have something weird.
00:33:12.120 --> 00:33:16.160
Email people and see if they can do it.
Because most people who have a PCB fab
00:33:16.160 --> 00:33:20.750
want money and will work for money.
Laughter
00:33:20.750 --> 00:33:24.135
Herald: Next question again center front
microphone, please.
NOTE Paragraph
00:33:24.135 --> 00:33:27.573
Question: Yeah. Very, very specific to
your talk.
00:33:27.573 --> 00:33:34.050
You said that the DXF format
that Fusion puts out is not directly
00:33:34.050 --> 00:33:40.390
readable, without loss, by KiCad. I missed
the software you use to convert it.
00:33:40.390 --> 00:33:45.490
Emily: Ah, it's DraftSight. So...
00:33:45.490 --> 00:33:47.420
... this ...
00:33:47.420 --> 00:33:50.410
this slide. So thats how it's spelled.
00:33:50.410 --> 00:33:51.650
Q: I see, thanks.
00:33:51.650 --> 00:33:54.430
A: Yeah, and in that software they have,
I don't know,
00:33:54.430 --> 00:33:59.650
maybe 20 different types of DXF and
other formats you can save things in.
00:33:59.650 --> 00:34:02.100
So when I worked for the Swiss watch
industry
00:34:02.100 --> 00:34:07.020
we would have to take all our files and
save it in the right one from customers.
00:34:07.020 --> 00:34:09.178
Herald: Next question, center front
microphone
00:34:09.178 --> 00:34:12.008
Question: Hey everybody.
If I wanted to find a lot of people
00:34:12.008 --> 00:34:15.118
who already know KiCad,
where would be the best place to look?
00:34:15.118 --> 00:34:17.300
Emily: An electrical
00:34:17.300 --> 00:34:19.790
Herald: Probably the workshop.
Emily: Yeah.
00:34:19.790 --> 00:34:21.125
Question: Well it's for beginners.
00:34:21.125 --> 00:34:23.510
I'm talking about people who already
know KiCad. It's like,
00:34:23.510 --> 00:34:26.820
is there like one main discussion
group in Usenet or something like
00:34:26.820 --> 00:34:30.079
central point on the internet to
find those people?
00:34:30.079 --> 00:34:33.770
Emily: Yeah.
Herald: The audience says: "Go to IRC.
00:34:33.770 --> 00:34:36.239
There should be a KiCad channel."
Emily: Again, I
00:34:36.239 --> 00:34:38.379
Herald: Probably on freenode.
Emily: Again, like he mentioned, I was a
00:34:38.379 --> 00:34:41.630
broken person, who couldn't leave my
appartment for actually it was a very,
00:34:41.630 --> 00:34:47.919
very long time. But, he was my answer for
everything. I was just like "I don't
00:34:47.919 --> 00:34:54.050
understand after an hour. Can you fix
it?", he's like "OK". So I'm not
00:34:54.050 --> 00:34:57.180
knowledgeable on that.
Herald: Next question from our signal
00:34:57.180 --> 00:35:00.585
angel handling the watchers at home.
00:35:00.585 --> 00:35:06.960
microphone issues
00:35:06.960 --> 00:35:19.935
Emily: Thanks.
00:35:19.935 --> 00:35:22.560
Herald: Next question center front
microphone.
00:35:22.560 --> 00:35:28.570
Question: Hi, thanks for your talk. I just
have question about the mousebites.
00:35:28.570 --> 00:35:34.040
How do you convert them from the
edgecut format to drilling, actually?
00:35:34.040 --> 00:35:39.700
Answer: So, I just leave them as edgecuts,
honestly, and they magically work.
00:35:39.700 --> 00:35:46.200
Mic: OK, not the answer I expected.
Thanks.
00:35:46.200 --> 00:35:51.700
Herald: Are there any more questions?
Last call for questions.
00:35:51.700 --> 00:35:54.880
No, doesn't look like it.
Well please give Emily Hammes
00:35:54.880 --> 00:35:57.375
a nice round of applause
for her excellent talk.
00:35:57.375 --> 00:36:06.770
Applause
00:36:06.770 --> 00:36:11.430
Emily: Yep, and if you are watching
online, not during congress
00:36:11.430 --> 00:36:13.335
you can contact me that way.
00:36:13.335 --> 00:36:18.252
postroll music
00:36:18.252 --> 00:36:38.000
subtitles created by c3subtitles.de
in the year 2019. Join, and help us!