react-native-printer-usb

React Native module to print on USB thermal printers (ESC/POS) for Android. Supports text, images (base64/URL), barcodes, QR codes, HTML, and raw commands. Handles accented characters, alignment, font, cut, beep, underline, and more.

Installation

npm install react-native-printer-usb

Android Setup

• No manual steps required for most React Native projects (autolinking).
• For custom setups, ensure USB permissions in AndroidManifest.xml:

<uses-feature android:name="android.hardware.usb.host" />
<uses-permission android:name="android.permission.USB_PERMISSION" />

Usage

List Devices

import { getList } from 'react-native-printer-usb';
const devices = getList();
// [{ vendorId, productId, deviceId, manufacturerName, productName, serialNumber, deviceName }]

Print Text

import { printText } from 'react-native-printer-usb';
await printText({
  text: 'Olá, mundo! Çãõé',
  productId, // required
  align: 'center', // 'left' | 'center' | 'right'
  encoding: 'CP850', // or 'utf8', 'ISO-8859-1', etc.
  bold: true,
  underline: true,
  font: 'A', // 'A' | 'B' | 'C'
  size: 2, // 1 (normal), 2 (2x), 4 (4x)
  cut: true, // cut paper after print
  beep: true, // beep after print
  tailingLine: true, // add blank lines at end
});

Print Image (Base64 or URL)

import { printImageBase64, printImageUri } from 'react-native-printer-usb';
await printImageBase64({ base64Image, productId, align: 'center' });
await printImageUri({ imageUri: 'https://...', productId, align: 'center' });

Print Barcode / QR Code

import { barCode, qrCode } from 'react-native-printer-usb';
await barCode({ text: '123456789012', productId, width: 2, height: 80 });
await qrCode({ text: 'https://reactnative.dev', productId, size: 6, align: 'center' });

Print HTML

import { printHtml } from 'react-native-printer-usb';
await printHtml({
  html: '<h1>Impressão HTML</h1>',
  productId,
  align: 'center',
  htmlHeight: 760, // px (optional)
});

Send Raw Data

import { sendRawData } from 'react-native-printer-usb';
await sendRawData({
  productId,
  text: '\x1B\x40Hello\n', // ESC/POS commands
  cut: true,
  tailingLine: true,
  encoding: 'utf8',
});

Cut, Reset, Beep

import { printCut, reset } from 'react-native-printer-usb';
await printCut(true, true, productId); // cut, beep, productId
await reset(productId);

Options Reference

| Option | Type | Description | | -------------- | --------- | -------------------------------------------- | | text | string | Text to print | | productId | number | USB Product ID (required) | | align | string | 'left', 'center', 'right' | | encoding | string | 'utf8', 'CP850', 'ISO-8859-1', etc. | | bold | boolean | Bold text | | underline | boolean | Underline text | | font | string | 'A', 'B', 'C' | | size | number | 1 (normal), 2 (2x), 4 (4x) | | cut | boolean | Cut paper after print | | beep | boolean | Beep after print | | tailingLine | boolean | Add blank lines at end | | base64Image | string | PNG/JPG base64 image (for printImageBase64) | | imageUri | string | Image URL (for printImageUri) | | html | string | HTML string (for printHtml) | | htmlHeight | number | Height in px for HTML print (optional) |

Example App

See example/App.tsx for a full-featured demo with device selection, all print types, and UI/UX best practices.

Troubleshooting

• Certifique-se de que o dispositivo USB está conectado e com permissão.
• Use encoding compatível com sua impressora (CP850, ISO-8859-1, etc).
• Para imagens, use PNG/JPG pequenos e alinhamento adequado.
• Para impressoras que não cortam/beep, ignore as opções cut/beep.

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

MIT

Made with create-react-native-library