Program the Serial Monitor

Step 1

What is the serial monitor?

The serial monitor is a screen that displays data that’s being transmitted between the computer and the Smart Inventor Board. To see it, click the magnifying glass icon in the upper righthand corner of the Arduino IDE.

Step 2

Use the serial monitor

After you click on the magnifying glass icon, the serial monitor will pop up in a separate window. It will show a stream of data, but only under a few conditions:

The serial monitor has to be in sync with the baud rate (information transferred in bits per second) of your programmed Smart Inventor Board. You can find this in the bottom righthand corner of the serial monitor window. Try 9600 baud!
Your Smart Inventor Board needs to be programmed to produce data.

Step 3

Use the serial monitor: the sequel

In the upper righthand corner of the serial monitor is a send button. After you type information into the serial monitor, you can click the send button and that information will be sent to the Smart Inventor Board — or whatever board that is connected! Using this feature allows you to do things like controlling your robot with your computer and keyboard. You can also receive information from the board with the serial monitor, like the distance a sensor is reading.

Step 4

Setup

Ready to program your serial monitor? Start by typing the line below within void setup():

Serial.begin(57600);

This line sets the amount of bits per second that the Smart Inventor Board will be sending data to the computer.

This is what Serial.begin() function looks like without the numbers:

Serial.begin(BAUD rate);

This function creates a high-transfer baud connection between the computer and the Smart Inventor Board. A higher baud number means the board will process information faster, but there’s also a higher chance for errors. A lower baud number means the board will process information slower, but there will also be less of a chance for errors.

Baud rates range anywhere from 300 to 250000. Make sure that your baud rate is a number that is found within the drop-down menu in the lower righthand corner of the serial monitor.

Step 5

Serial.println()

You’re moving on to void loop() now!. Type the line of code below after void loop(). This message will be output from the Smart Inventor Board once it is uploaded.

Serial.println("Hello World");

The command Serial.println(“Some words”) prints a new line with the text inside the ” ” signs.
The ln creates the message on a new line. If the command Serial.print(“some more words”) was used without the ln part, the words would be on the same line as the last message.

The “Hello World” program has been used to introduce beginner programmers to a new programming language since the 1970s. Welcome to Arduino!

Step 6

delay()

Looping programs are great! In this case, they output a message as fast as the board can. However, that might be a little too fast, so to slow it down, type in the line below at the end of your program, between the serial.println line and the curly brace.

delay(250);

Upload your entire program to your board, open up the serial monitor, and you should be able to see the message “Hello World” repeatedly.

You’re done! Here’s the final code:

void setup(){

Serial.begin(57600);

}

void loop(){

//display hello world
Serial.println("Hello World");
delay(250);

}

Step 7

Video

Still need some help? Watch the video!

This lesson uses:

Grade level:

Approx. time required:

CSTA

CCSS