Libraries not found

Other
1

Recently migrated from an old Toshiba laptop to MacBook. Installed Arduino IDE and can write and upload simple code fine. I have some old Blynk projects trying to update and IDE won’t compile citing libraries not found. I manually copied all the library files into the libraries folder on the Mac . Do I need to go thru some other process so the compiler can find the libraries? Does every .h library file need to appear as a separate tab in your code file in order for the compiler to use it?

2

1. Library Installation for Arduino IDE (on Mac)

While copying the library files manually into the libraries folder may work in some cases, Arduino IDE also has a built-in way to library manager that might be more reliable:

Here’s a method:

  • Open Arduino IDE.
  • Go to Sketch > Include Library > Manage Libraries.
  • In the Library Manager, you can search for the libraries you’re using (like the Blynk library) and install them from there. This ensures the libraries are properly linked and recognized by the IDE.
  • If you’re working with older libraries that are no longer available from the Library Manager, make sure you’re placing the .h and .cpp files into the correct folder:
    • Documents/Arduino/libraries/ on macOS (make sure the folder name is the library’s name, not just a folder full of files)

If you do manually copy libraries, make sure:

  • The library folder itself is in the right place: Documents/Arduino/libraries/.
  • The library files are contained within a folder named after the library (for example, Blynk), and that folder contains the .h and .cpp files

2. Do .h Files Need to Appear in Code Tabs?

No, you don’t need to manually create separate tabs for each .h file in your code. Instead, you include the library in your code with the #include directive at the top of your main sketch file

Example:

#include <BlynkSimpleEsp8266.h>

As long as the Arduino IDE can find the library (via proper installation in the libraries folder), you don’t need to create separate tabs for each .h file. The compiler will automatically pull in the library when it sees the #include directive

3. Check the Library Path and Permissions

Sometimes, the IDE might have issues finding libraries if there are permission issues or misconfigurations. Here’s what you can check:

  • Make sure that the libraries folder is located in the correct place (Documents/Arduino/libraries/).
  • Make sure that the files inside your libraries folder are not being blocked by macOS security settings (right-click on the folder/file, select Get Info, and make sure there are no restrictions).
  • If you’ve used a different folder for libraries, make sure the IDE is looking in the correct location. You can configure this under Arduino IDE > Preferences, and check the “Sketchbook location”

4. Compiling the Sketch

Once the libraries are properly installed or copied:

  • Restart the Arduino IDE after adding or updating libraries to make sure the IDE recognizes them.
  • Try compiling again. The error should be resolved if the libraries are correctly found

Additional Tip:

  • Updating Blynk: Make sure you’re using the latest version of the Blynk library if your projects are outdated. Blynk 2.0 uses a different API, and older sketches may require modifications to work with the newer versions
3

Thanks for all this detail. I’ll look into it

4

Ok created folder tree as described for the libraries. Installed latest Blynk libraries as far as I am aware. When tried to compile the code, the compile ran for about 5 seconds longer this time but still got errors. - see error message below . Any suggestions?

In file included from /Users/philpyrce/Documents/Arduino/libraries/Blynk/src/BlynkApiArduino.h:14,
from /Users/philpyrce/Documents/Arduino/libraries/Blynk/src/BlynkSimpleEsp8266_SSL.h:27,
from /Users/philpyrce/Documents/Arduino/water_blynk_01_copy_20250316153802/BlynkEdgent.h:9,
from /Users/philpyrce/Documents/Arduino/water_blynk_01_copy_20250316153802/water_blynk_01_copy_20250316153802.ino:23:
/Users/philpyrce/Documents/Arduino/libraries/Blynk/src/Blynk/BlynkApi.h:39:6: error: #error “Please specify your BLYNK_TEMPLATE_ID and BLYNK_TEMPLATE_NAME”
39 | #error “Please specify your BLYNK_TEMPLATE_ID and BLYNK_TEMPLATE_NAME”
| ^~~~~
exit status 1

Compilation error: exit status 1

5

additional information . This code was originally created and compiled on June 1 , 2022.

6

note- I tried compiling some other Blynk IoT codes I had written around the same time and they are all generating the same error message . Is this a Blynk2.0 API issue? How to fix?