VS Code giving header errors for Arduino? Missing official header?

Question

I've recently started developing for Arduino. Initially I used the Arduino IDE but I soon realised it was not up to par. Development was considerably slower with the need for IDE restarts every now and then. I found VS Code with the Arduino Extension which I've come to love. However I have a few issues and I'm not sure how to solve it.

First of all vs code throws #include errors and asks me to update IntelliSense. However it builds/uploads and runs perfectly well, it also finds the classes etc. defined in said includes so it looks like it's a false positive in some way (i.e. the path is included in includePath settings). Reading the error message also shows it having issues finding a header referenced in Arduino.h called "avr/pgmspace.h". I'm unsure if these errors are related. pgmspace.h is nowhere to be found (it should have been included in the Arduino SDK).

Finally because of the #include error anything related to that particular header file will not be highlighted properly and is just plain gray text which is a bit annoying.

Anyone knows how to fix this? I'm on a Mac btw.

Answer 1

The accepted answer didn't work for me. Can't find nor create c_cpp_properties.json file. Also, I wanted it to be global, and not only to one project/workspace/folder.

So, for VSCode 1.14 (2019) I just navigate till settings.json (the global one), and add this json section:

"C_Cpp.default.includePath": [
    "C:/Program Files (x86)/Arduino/libraries/**",
    "C:/Program Files (x86)/Arduino/hardware/arduino/avr/cores/arduino/**",
    "C:/Program Files (x86)/Arduino/hardware/tools/avr/avr/include/**",
    "C:/Program Files (x86)/Arduino/hardware/tools/avr/lib/gcc/avr/5.4.0/include/**",
    "C:/Program Files (x86)/Arduino/hardware/arduino/avr/variants/standard/**",
    "C:/Users/<YOUR USERNAME>/.platformio/packages/framework-arduinoavr/**",
    "C:/Users/<YOUR USERNAME>/Documents/Arduino/libraries/**",
    "{$workspaceFolder}/libraries/**",
    "{$workspaceFolder}/**"
],
"C_Cpp.intelliSenseEngine": "Tag Parser"

Posted another answer with the entire procedure and all details about the approach: Visual Studio Code includePath

Answer 2

Update: Extra libraries do not need to be installed. IntelliSense can operate using only the headers installed by the Arduino app, but a few others may help. More updates below.

When VSCode builds, it uses the SDK. However, IntelliSense cannot read the SDK files to operate (as far as I can tell), which throws these annoying errors and eliminates most code completion capabilities.

Both includePath and browse.path need to be configured. includePath does not include recursively (but that feature seems to be coming soon). browse.path is recursive, but including the exact location of header files is in includePath is still necessary for IntelliSense features. browse.path will use the Tag Parser to provide tools such as the "lightbulb" that you can click to help resolve your includePath issue. (Source: What is the difference between "includePath" and "browse.path" in c_cpp_properties.json?)

---

Mac:

avr/pgmspace.h is located at: /Applications/Arduino.app/Contents/Java/hardware/tools/avr/avr/include/avr/pgmspace.h. It's coded into the libraries as avr/pgmspace.h; for this reason, we need to include the path that avris located in.

1. Install homebrew-avr:

2. Edit c_cpp_properties.json:

"includePath": [
    "${workspaceFolder}/libraries",
    "/System/Library/Frameworks/Kernel.framework/Versions/A/Headers",
    "/Applications/Arduino.app/Contents/Java/libraries",
    "/Applications/Arduino.app/Contents/Java/hardware/tools/avr/avr/include",
    "/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/variants/standard"
],
"browse": {
    "limitSymbolsToIncludedHeaders": false,
    "path": [
        "/System/Library/Frameworks/Kernel.framework/Versions/A/Headers",
        "/Applications/Arduino.app/Contents/Java/"
    ]
},
"forcedInclude": [
    "/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino/Arduino.h"
],

---

Windows 10:

1. Install WinAVR

2. Edit c_cpp_properties.json:

Revise includePath to look like this:

"includePath": [
    "{$workspaceFolder}/libraries",
    "C:/Program Files (x86)/Arduino/hardware/tools/avr/lib/gcc/avr/5.4.0/include",
    "C:/Program Files (x86)/Arduino/hardware/arduino/avr/cores/arduino",
    "C:/Program Files (x86)/Arduino/hardware/arduino/avr/variants/standard",
    "C:/Program Files (x86)/Arduino",
],

---

Alternative Method (probably a bad idea):

If you can get a version of any missing library, you can probably put in in your libraries folder of your project if your includePath includes "${workspaceFolder}/libraries". Make sure to namespace your libraries appropriately, e.g. libraries/avr/pgmspace.h. I have not tested this method.

---

Updates:

• Changed from home.path to includePath. See more here: vscode-cpptools/FAQ
• The tools downloaded by the vscode-arduino libraries are not necessary on Windows 10.
• Changed Windows config paths to use forward slashes instead of escaped backslashes.

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Source and further tips: Enabling Arduino Intellisense with Visual Studio Code