link I want add the dfu library to my project.
it has a download oètopn, but there is no direct download and it says to use Gradle to add it.
Anyway, the documentation says to do this step.
Clone the project, or just the DFULibrary folder (using sparse-checkout) to a temporary location.
Copy the DFULibrary folder to your projects root, for example to AndroidstudioProjects.
Add the dfu module to your project:
Add '..:DFULibrary:dfu' to the settings.gradle file: include ':app', '..:DFULibrary:dfu'
Open Project Structure -> Modules -> app -> Dependencies tab and add dfu module dependency. You may also edit the build.gradle file in your app module manually by adding the following dependency: compile project(':..:DFULibrary:dfu')
But I can't find the DFULibrary folder in this project .