To use ArduinoJson within Atmel Studio 7, do not use the “Add Arduino Library” feature.

Instead, use one of the following solution.

Option 1: Set include directory

  1. Download (or git clone) ArduinoJson where you want.
  2. Right-click on target project and click Properties
  3. Open the Toolchain tab
  4. Under Compiler / Directies, click on Add Item A dialog box entitled “Add Include Paths (-I)” should appear.
  5. Enter the location of the src/ folder of ArduinoJson

Now the compiler knows where to find ArduinoJson.h.

Option 2: Use “single header” version

  1. Download the “single header” from the Releases, for example ArduinoJson-v5.10.0.h. (you cannot use git clone to get the “single header”)
  2. Copy this file in your project folder.

The compiler will find ArduinoJson-v5.10.0.h as it’s in your project folder.