$ npm install react-native-gpio --save

$ react-native link react-native-gpio

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

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

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

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

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

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

Please use this link to view Android Things (e.g. Raspberry Pi) I/O documentation: raspberrypi-io. Use the name for the GPIO pin for subscription.

import RNGpio from 'react-native-gpio';

...

componentDidMount(){

    // register for gpio pins
    RNGpio.subscribeGpio("BCM14");

    // register for events
    DeviceEventEmitter.addListener('RNGPIO', (event: GpioEvent) => {
      
      /**
       * Sample event: {
       *  "BCM2": true
       * }
       */
      this.setState({
        pins: {
          ...this.state.pins,
          ...event
        }
      })
    });
}

...