External USB Fingerprint scanner

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Summary

The goal of this article is to discuss the technical challenges of integrating an external USB fingerprint scanner with a React Native app (Expo) for both iOS and Android platforms. Key considerations include compatibility, security, and platform-specific limitations.

Root Cause

The root cause of the complexity in achieving this integration lies in the following factors:

  • Lack of direct support for external USB devices in React Native
  • Platform-specific APIs for fingerprint scanning, which require native module implementation
  • Security restrictions imposed by both iOS and Android on accessing external devices

Why This Happens in Real Systems

This challenge occurs in real systems due to:

  • Diverse hardware support: External USB fingerprint scanners vary in compatibility and driver requirements
  • Security protocols: Both iOS and Android have strict security protocols to protect user data, limiting direct access to external devices
  • Software integration complexities: Integrating third-party hardware with mobile apps involves navigating through different software frameworks and APIs

Real-World Impact

The impact of not addressing these challenges effectively includes:

  • Failed integration: Inability to successfully integrate the fingerprint scanner with the React Native app
  • Security vulnerabilities: Potential exposure of user data if integration is not handled securely
  • Limited functionality: App may not perform as expected across different platforms and devices

Example or Code

To integrate a fingerprint scanner, one might use a library like react-native-fingerprint-scanner for Android. However, implementing support for an external USB fingerprint scanner requires more complex native module development.

import React, { useEffect, useState } from 'react';
import { View, Text } from 'react-native';
import FingerprintScanner from 'react-native-fingerprint-scanner';

const App = () => {
  const [isAuthorized, setIsAuthorized] = useState(false);

  useEffect(() => {
    const authenticate = async () => {
      try {
        await FingerprintScanner.authenticate();
        setIsAuthorized(true);
      } catch (error) {
        console.log(error);
      }
    };
    authenticate();
  }, []);

  return (
    
      Fingerprint Scanner Example
      {isAuthorized? Authorized : }
    
  );
};

export default App;

How Senior Engineers Fix It

Senior engineers address this challenge by:

  • Developing native modules for both iOS and Android to interact with the external USB fingerprint scanner
  • Implementing platform-specific code to handle the differences in API calls and security protocols
  • Ensuring secure data handling practices to protect user fingerprint data
  • Thoroughly testing the integration across various devices and platforms to ensure compatibility and functionality

Why Juniors Miss It

Junior engineers might miss addressing these complexities due to:

  • Lack of experience with native module development and platform-specific APIs
  • Insufficient knowledge of security protocols and best practices for handling sensitive user data
  • Underestimating the complexity of integrating third-party hardware with mobile apps across different platforms