$ npm install react-native-pi4j --save

$ react-native link react-native-pi4j

1. Open up android/app/src/main/java/[...]/MainActivity.java

• Add import com.reactlibrary.RNPi4jPackage; to the imports at the top of the file
• Add new RNPi4jPackage() to the list returned by the getPackages() method

2. Append the following lines to android/settings.gradle:

   include ':react-native-pi4j'
   project(':react-native-pi4j').projectDir = new File(rootProject.projectDir, 	'../node_modules/react-native-pi4j/android')
   

3. Insert the following lines inside the dependencies block in android/app/build.gradle:

     compile project(':react-native-pi4j')
   

import RNReactNativePi4j from 'react-native-pi4j';

// TODO: What to do with the module?
RNPi4j;