expo-r330-printer

Expo module (React Native / Expo) wrapper for vendor R330 series receipt printer service (Android).
This repo contains the native Android module and a small Expo example app used for testing.

⚠️ This module relies on a vendor Android service that exposes an AIDL interface: recieptservice.com.recieptservice.PrinterInterface. Make sure that service is available on target devices.

Quick install (consumer project)

From a consuming project (React Native / Expo with autolinking enabled):

# If published to npm (replace with actual package name)
npm install expo-r330-printer
# or
yarn add expo-r330-printer

Then rebuild native app:

# For bare React Native
npx react-native run-android

# For Expo (dev client)
npx expo run:android

If you are using the managed Expo client (not a dev client), native modules won't work — you must use a custom dev client or bare workflow.

Usage (JS / TS)

This module exposes a simple API. Example usage in React:

import ExpoR330Printer from "expo-r330-printer";

async function test() {
  try {
    // Bind to the vendor printer service
    await ExpoR330Printer.bind();

    // Print text
    await ExpoR330Printer.printText("Hello from Expo!\n");

    // Print a base64 PNG image (data URI or raw base64)
    await ExpoR330Printer.printBitmapBase64("data:image/png;base64,...");

    // Print raw Epson bytes (send as base64)
    await ExpoR330Printer.printEpsonBase64("<base64-data>");

    // Print barcode / QR
    await ExpoR330Printer.printBarCode("123456", 6, 162, 2);
    await ExpoR330Printer.printQRCode("https://example.com", 4, 3);

    // Text formatting
    await ExpoR330Printer.setAlignment(1); // 0 left,1 center,2 right
    await ExpoR330Printer.setTextSize(24); // number
    await ExpoR330Printer.setTextBold(true);
    await ExpoR330Printer.nextLine(1);

    // Table printing
    await ExpoR330Printer.printTableText(["Item","Qty","Price"], [1,1,1], [1,1,1]);

    // Unbind
    await ExpoR330Printer.unbind();
  } catch (e) {
    console.error("Printer error", e);
  }
}