- [Instructor] Are you
wondering what serial begin with that 9,600 in the parentheses does? You've probably seen it in almost all the Arduino
programs you've looked at but what's it there for? Do you even need to use serial begin? What if you change the number 9,600? I mean what's 9,600 even mean? In this lesson, you will learn exactly
what serial begin does, when you need to use it and what the heck the 9,600 means. Stay tuned. (upbeat music) Subscribe to our YouTube channel to get more videos like this. So what does serial begin do? Let's get straight to this. Serial begin establishes
serial communication between your Arduino
board and another device. The most common use of
serial communication that you will establish
is between your Arduino in your computer via a USB cable, or should I say universal
serial bus cable. When you have established
serial communication between two devices, it
allows the two devices to communicate using a serial protocol. So let's answer a couple
practical questions. When do you actually
need to use serial begin? So the most common reason
to use serial begin is when you want to
output some information from your Arduino to your computer screen. That is if you want to
like print some text out. The function that's used to display text on your computer screen
from your Arduino board is the serial print function. The text that gets printed out shows up on the serial monitor
window, which you can open up in the Arduino IDE menu bar
under tools, serial monitor or with the shortcut key
control shift M on PC or command shift MAC OS. Now there's other times
you'll use serial begin. For example, you may have
an application running on your computer that
will be expecting data from your Arduino over a serial port. In these cases, you'll
also need serial begin. So where does serial begin
go in an Arduino sketch? 99% of the time, you'll be
putting the serial begin function inside the setup function
inside your Arduino sketch. So as you may know, the setup function only runs once and you only need to establish
serial communication one time and it will last the length of your sketch which is why it makes sense
to put the function inside of setup. So what's with the number 9,600? That number is called the baud rate. And it's basically the rate at which your two devices will be
communicating over serial. Probably the most practical
thing you need to know is that for serial communication to work, the baud rate in serial begin and the baud rate set on the
receiving device need to match. If you're using the Arduino
IDE serial monitor window to read information from your Arduino, then you can use the baud rate drop down to set the baud rate. Remember, if these two values don't match, then anything you try to send over serial will not work right. It's like as a kid, did you
and a friend ever come up with a long distance
communication protocol, like two hoots? Woo, woo. Is anyone at the Fort? And the appropriate response
back was like two hoots. But if you both didn't agree
on that protocol beforehand and your friend's like call,
call, instead of hooting then you're like,
"What's he trying to say? Don't he like my shoes
or something like that?" It's the same thing with the baud rate. Remember, these have to match. All right. So let's do a review. Serial begin is used to
establish serial communication. Serial communication is one way to allow devices to talk to each other. Most often, you'll be using serial begin when you want to print something
out to your computer screen from your Arduino. This would also require
the serial print function. The serial begin function generally goes inside a void setup. Well, hey, I hope you
found this really helpful. Make sure to check out
Programming Electronics Academy for tons of other information
about serial communication. This is just the tip of the iceberg. Have a great one. Bye. (upbeat music)
