[MUSIC]
[SOUND] So we're still talking about electrical circuits,
about the hardware side of these IOT devices.
Now, you know, we understand V equals IR, Ohm's law and so forth, that relationship.
But you're eventually gonna have to actually build these things physically.
You're gonna have to take these components.
And we saw a battery, some kind of power source, wires, resistor.
There are lots of different components.
Eventually you're gonna have to take these and actually plug them together and
make a circuit out of them.
Okay?
Now, typically, when you do that, you also have what's called a schematic diagram.
And we're gonna show some of these.
But, so you start off.
Usually when, say you're thinking of a new design.
What you do is you write, you draw out a schematic.
A drawing of what should be connected to what.
Now this schematic drawing, typically, it shows what components connected to what,
what terminals connect to what.
But it doesn't show exact placement.
It doesn't show how it will physically look in the real world.
It shows, though, how you would expect it to be connected electrically.
So these schematics, we're going to have to get used to reading these schematics.
And given a schematic,
you're going to have to get used to taking that schematic and implementing it.
Meaning wiring some components together according to the schematic, okay.
So that's the type of stuff we're gonna cover right now.
And so we're gonna go through some of these electrical components
that you commonly see, just so you know what they look like and
what their schematic symbols look like.
So that you can understand what a schematic diagram looks like, and
then you can understand how that matches the actual physical implementation that
you're gonna work on.
So up here we have resistors.
So on the left you see a batch of resistors so those
are your standard resistors and they can look different but that is a common look.
So if you look at those resistors and
you can see next to it there's a schematic symbol that little
saw tooth type of diagram saw tooth thing that's a resistors schematic symbol.
Now a resistor, it provides resistance to the current flow.
So we already talked about what a resistor's supposed to do.
A resistor has two terminals, two leads, right, two wires coming out of it.
If you look at any one of those resistors there's two wires, one on each side.
And it doesn't matter which one, they're equivalent, so current could flow either
direction through there, it doesn't matter which one is which, which side is which.