Importing Libraries - Air Quality Monitoring Station Series, Episode 9

By including these libraries, you can take advantage of their prebuilt functions. For example:

• You can use tft.fillScreen() to easily clear or change the background of the screen.
• Functions such as tft.drawString() let you print text on the screen without worrying about low-level communication.

Example of using a library

To see how libraries simplify your work, here is a quick example using the TFT_eSPI library for a TTGO T-Display. The goal is to initialize the screen and print some text.

#include <TFT_eSPI.h> // Inkluder TFT-biblioteket

TFT_eSPI tft = TFT_eSPI(); // Opret et display-objekt

void setup() {
  tft.init(); // Initialiser displayet
  tft.fillScreen(TFT_BLACK); // Ryd skærmen med sort baggrund
  tft.setTextColor(TFT_WHITE, TFT_BLACK); // Sæt tekstfarve
  tft.drawString("Welcome!", 10, 20, 4); // Skriv tekst på koordinaterne (10, 20) med skriftstørrelse 4
}

void loop() {
  // Her kan du opdatere skærmen med nye data
}

With just a few lines of code, the library lets you control the screen — initialize it, set colors, and print text — without needing to understand how the display controller works internally.

Step 3: Managing and updating libraries

Proper library management ensures that your project remains functional and up to date. Here are some useful tips:

1. Updating libraries:

   • Occasionally, you may need to update libraries to ensure compatibility with new versions of Arduino IDE or to obtain new features. In the Library Manager, you can see whether updates are available for installed libraries and update them with a single click.

2. Uninstalling libraries:

   • If you need to remove a library, you can uninstall it via the Library Manager. Find the library and select Uninstall.

3. Adding libraries manually:

   • Sometimes you need to install a library manually if it is not available in the Library Manager. In those cases, you can download the library as a ZIP file and use Sketch > Include Library > Add .ZIP Library… to install it.

Step 4: Common library problems and troubleshooting

1. Library Not Found Error:

   • If you get an error saying a library cannot be found, check that it is installed correctly via the Library Manager and that your #include statement is spelled correctly.

2. Library conflicts:

   • Sometimes multiple versions of the same library can cause conflicts. You can resolve this by uninstalling older versions or specifying which version to use in the Library Manager.

3. Version compatibility:

   • Some libraries depend on specific board versions or Arduino IDE versions. Always check the documentation to ensure that the library version is compatible with your setup.

Summary

In this lesson, you have been introduced to the concept of libraries in Arduino IDE. Libraries are powerful tools that save time and reduce complexity by providing prewritten functions for hardware components and much more. You have now learned how to search for, install, and include libraries in your sketches using Arduino IDE's Library Manager.

In future lessons, we will take a closer look at how to use specific libraries to work with hardware such as sensors and displays. Understanding how to manage libraries will make it easier for you to add more advanced features to your IoT projects.