@countertek/react-native-esc-pos-printer

Expo native module for Epson TM ESC/POS printers.

Discovery is available through PrintersDiscovery and usePrintersDiscovery. Connect a Printer with connect, disconnect, and getStatus. Print a text receipt with run and the Command Buffer.

Discovery

Add the package to the Expo app's plugins array, rebuild the development client, then request permission before starting Discovery:

import {
  PrintersDiscovery,
  getDiscoveryPermissions,
  requestDiscoveryPermissions,
} from '@countertek/react-native-esc-pos-printer';

const current = await getDiscoveryPermissions();
if (!current.granted) {
  await requestDiscoveryPermissions();
}

PrintersDiscovery.start();

Subscribe with PrintersDiscovery.onDiscovery, onStatusChange, and onError, or use usePrintersDiscovery for React state. granted reports Bluetooth; start Discovery even when it is false so LAN and USB printers can still be found. The config plugin writes the required Bluetooth, local-network, and external-accessory permission entries.

Printer session

import { Printer, PrinterConstants } from '@countertek/react-native-esc-pos-printer';

const printer = new Printer({
  target: 'TCP:192.168.1.50',
  deviceName: 'TM-T88V',
});
await printer.connect();
const status = await printer.run(async (buffer) => {
  await buffer.addTextAlign(PrinterConstants.ALIGN_CENTER);
  await buffer.addText('Hello\n');
  await buffer.addFeedLine(2);
  await buffer.addCut();
  return buffer.sendData();
});
await printer.disconnect();

connect on an already-connected Printer succeeds. Nested run on the same Printer throws. getStatus and a successful sendData return connection, online, coverOpen, paper, and errorStatus. add* and sendData live on the Command Buffer passed to run, not on Printer.

Documentation

• v0.1 development specification
• Architecture decisions
• Legacy 4.x documentation for the unscoped package

Development

Install the library dependencies:

pnpm install

Install and run the Expo SDK 56 example:

cd example
pnpm install
pnpm ios
# or
pnpm android

The example uses Expo Router and a development client. Expo Go is not supported because this package contains native modules.

License

MIT