Okay, this is the big test. Let’s power
it on and see if it works.
Well, that’s promising. We have two
LEDs. So, we got 5 volts and 3.3 volts.
Blinking LED. Perfect. So, we have a
blue, a red, and a green. And the green
one is blinking. That’s hooked up to a
GPI open. Fantastic.
So, I finally got round to assembling my
super simple ESB32S3
dev boards. So, the PCBs came from PCB
way a couple of weeks back and they came
out really well. So, it is a really,
really super simple devboard. You could
make one yourself quite easily. We’ve
based it on the ESP32 S3 V room module.
And the nice thing about this is you can
connect it directly to a USB. So, you
don’t need a USB to UR chip. It just
plugs straight in. Um, our board’s very
very simple. We have a voltage
regulator. So, we take the 5 volts from
the USB and turn it into 3.3 volts.
We’ve got the decoupling capacitors on
the input and on the output. There’s the
reset button. And then we’ve got the um
some LEDs just to indicate what’s going
on. So, a 5V, 3.3 volt, and one hooked
up to a GPIO pin. And then we’ve broken
out all of the pins onto a header. So,
it is a very basic devboard. Let’s get
on with assembling it. So, the easiest
way to get these boards assembled is to
use the provided stencil from PCB way.
So, I’ve already done that here. I take
the stencil down, put the solder paste
on, and then use my spudger to squeeze
the solder paste onto the actual pads.
Now, it didn’t come out perfectly. I
wasn’t quite sort of flat, but we just
need to place the components now, and
then we’ll put it on the um on the hot
plate and melt all the solder. So, we’re
just placing all the components. Here’s
the buttons. There’s a bunch of um
resistors, some resistors for the
diodes. So, stick those on. Here’s the
actual diodes. So, I think these are
red, green, and blue. May have got those
mixed up, though. Bunch of decoupling
capacitors to stick on. And then we’re
pretty much done. Stick it on the hot
plate and heat it up. Everything jumps
nicely into place.
Now, the only bit that didn’t quite work
due to a slightly messy solder post job
is the actual USB socket. So, we had a
few solder bridges. So, we just run the
soldering iron over these just to make
sure that they are connected and there’s
no solder bridges. Then, it’s the solid
test. So, solid, solid, solid, solid,
solid solid solid solid solid and
solid.

Okay, so that was using a stencil. Let’s
do it manually. So, I’ve got everything
taped up here. We’ll do the more
difficult components first. So, let’s
start off with the USB socket. I’ll
switch over to the microscope for this.
Okay, so we’re under the microscope. Um,
everything’s lined up nicely. We’ll add
some flux.
Now, some of these pins will be tricky
because there’s quite a big ground
plane. So, we may need to kind of add
quite a lot of heat. So, what I might do
is start with some of the pins in the
middle and work my way out. That way,
the board would have got warmed up. So,
when we hit the end pins, they’ll be
nice and hot. So, let’s make a start on
that.
So, I’ve got my soldering iron here.
Hopefully, you can see all this as well
as I can.
One pin,
two
[Music]
That looks clean enough so we can
actually see what we’re doing. Let’s
check these are all solid. So there we
go. Let’s stick this in. So solid.
Solid. Solid. Oh, not solid.
Fact. Lots of these aren’t solid.
Okay. Solid test mark two. Solid. Solid.
Solid.
Solid. Solid. Solid.
And
solid.
Not bad. Done. Couple of tries, but we
did it in the end. Let’s give it another
clean up. And I think that’s good. Quick
double check. Make sure we’ve not
loosened them by our rigorous cleaning.
So, still solid. Still solid. Still
solid. Yeah, nice and solid.
Everything’s nice and solid. So, what I
might do before we move on to anything
else is flip the board over and make
sure our socket is really nice and
secure.
So, there we go. Nicely secured.
Let’s move on to the next part of the
board, which will be the soldering of
the ESP32 module. So, we’ll do that
next. Now, there’s got a misconception
that you need to solder these um these
pads here, the thermal relief pads. It’s
not really necessary unless you want
really good thermal performance. So,
check out the data sheet for
confirmation of that. But, we’ll just
solder it on the actual pads around the
edges.
So that’s next. Solder up the ESP32
module. And the trick with soldering
these up is to get the alignment right.
So let’s uh align these and the bottom
ones. And what I’ll do is I’ll tape this
down. And then we’ll just solder one pin
whilst we’re pushing down on the module.
And hopefully we’ll get it all sorted up
nicely. So let’s just get this alignment
nice.
[Music]
Okay, so I got the uh PCB plugged into a
bit of breadboard just to hold it still.
Let’s try plugging it in and see if it
works. So, let’s get the USB connector
in.
Well, so far that’s promising. We have
um two LEDs lit. Got a blue one and a
red one. Hard to see in the video cuz
the uh the camera kind of gets a bit
washed out. Let’s see if I can improve
the display.
Yeah. Well, you can kind of see there’s
a blue and a red LED.
So, let’s see if we actually enumerate.
So, we can do this on a Mac or Unix
computer. Just um see if we have a USB
device showing up. Well, that’s pretty
promising. So, this is our device. Well,
I’ve got a simple blink sketch here.
Let’s see if we can actually program our
board and see if it starts blinking.
Even more promising. It’s writing the
program. So, we’re storing our code in
flash. And there we go. A blinking
light. So, I think our our next video in
this kind of series, let’s um let’s take
our devboard and uh professionalize it.
We’ll need to work out what a
professional devboard actually means,
but this is a very very basic devboard.
So, there’s a lot you can do to improve
this if you were going to go to
production. So, let’s do that in the
next video.