Arduino Serial Monitor is not working? Try these 5 steps

by Radu Tyrsina
Radu Tyrsina
Radu Tyrsina
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Radu Tyrsina has been a Windows fan ever since he got his first PC, a Pentium III (a monster at that time). For most of the kids of... read more
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  • The Arduino board has a Serial Monitor function that you can use to print your coded data. It sometimes happens to get a blank page instead, which is frustrating.
  • In this article, we're looking at some basic things that you can check just to make sure that you're getting everything right for the Serial Monitor to work.
  • If you're a fan of this programming board, make sure to take a look at our dedicated Arduino Hub.
  • Also, in our Developer Tools section, you might find other insightful information.
fix arduino serial monitor not working

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With Arduino, the Serial Monitor is a feature that can help in debugging sketches or controlling the device from your computer’s keyboard. Also,  you will use the Serial Monitor to view data sent by a working sketch.

To see the Serial Monitor, the Arduino must be connected by USB to your computer.

However, sometimes the Serial Monitor just shows a blank page. Although, the Arduino sketch contains Serial.print() and Serial.println() functions, the text doesn’t appear in the serial monitor.

In this article we’ll be looking at some basic troubleshooting steps that should be useful.

What should I do if the Arduino Serial Monitor isn’t working?

1. Verify the communication ports

Arduino and the Arduino IDE should be connected to the same communications port. Unplugging and plugging back the Arduino can switch the ports.

For a simple check, re-upload the sketch from the same IDE that you are using to open the Serial Monitor.

2. Match the band rate on the Serial Port

The Serial Monitor on the computer and the Serial Port on the Arduino must have the same data rate (baud rate).

Usually, the baud rate is 9600, so the programming statement is Serial.begin(9600). Set the same value for the Serial Monitor from the dropdown box in the lower-right corner. 

3. Make sure the programming statements are being executed

The Serial.begin() and Serial.println() programming statements must be executed. Sometimes a branching statement, such as if and else, will cause these statements to be missed.

Also, if they are not being executed, the Serial Port will not function.

4. Check the statements for syntax errorsarduino monitor not working

Examine the Serial.print() and Serial.println() statements for syntax errors. Since print and println are common among several programming languages, sometimes a usage that is valid in one doesn’t work with the Arduino.

5. Check the wiring

Insect the wiring of any circuit connected to the Arduino. The digital pins 0 and 1 should not be used. Both are connected to the components on the Arduino that performs the serial text communication and may not be simultaneously used for something else.

To conclude, we hope that these indications were somewhat helpful to fix the Serial Monitor issue. Any feedback is welcome in the comments section below.

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Frequently Asked Questions

  • The Serial Monitor is a feature that comes with all versions of the Arduino IDE. The Serial Monitor icon is located to the right or far right of all the other icons in the menu.

  • The Arduino sends data from your sketch on a PC or Mac via serial links. The Serial.begin() function makes the call to your sketch and then Serial.print() prints the text and values you want to see in the Serial Monitor.

  • For Mac, you can find this detail in Tools.  For Windows, explore our comprehensive Arduino driver installation guide for more details.

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