Dart SDK

The Dart SDK supports cross-platform Flutter applications on iOS, Android, Windows, and macOS.

Installation

All packages are published on pub.dev. Search for the psdk prefix.

Core packages

dependencies:
  psdk_frame_father: ^latest   # Core framework
  psdk_device_adapter: ^latest # Device adapter

Command packages (choose as needed)

dependencies:
  psdk_fruit_cpcl: ^latest  # CPCL Commands
  psdk_fruit_esc: ^latest   # ESC Commands
  psdk_fruit_tspl: ^latest  # TSPL Commands

Bluetooth packages (choose by platform)

dependencies:
  psdk_bluetooth_ble: ^latest      # BLE (iOS/Android/macOS)
  psdk_bluetooth_classic: ^latest  # Bluetooth Classic (Android)
  psdk_bluetooth_windows: ^latest  # Windows Bluetooth

Available packages

Package name	Description	Platform
psdk_frame_father	Core framework	All platforms
psdk_device_adapter	Device adapter	All platforms
psdk_bluetooth_ble	BLE	iOS/Android/macOS
psdk_bluetooth_classic	Bluetooth Classic	Android
psdk_bluetooth_windows	Windows Bluetooth	Windows
psdk_fruit_cpcl	CPCL commands	All platforms
psdk_fruit_esc	ESC commands	All platforms
psdk_fruit_tspl	TSPL commands	All platforms
psdk_network	Wi-Fi connection	All platforms
psdk_usb_standard	USB connection	Android
psdk_usb_windows	USB connection	Windows

Platform notes

Choosing Bluetooth

• iOS/macOS: Use BLE (psdk_bluetooth_ble) only
• Android: Bluetooth Classic (psdk_bluetooth_classic) is recommended for better performance

Quick start

1. Scan for devices

import 'package:psdk_bluetooth_classic/psdk_bluetooth_classic.dart';

// Start Bluetooth scanning
await ClassicBluetooth().startDiscovery(
  disconnectConnectedDevice: false
);

// Listen for scan results
ClassicBluetooth().discovered().listen((devices) {
  for (final device in devices) {
    print('Device found: ${device.name}');
  }
});

2. Connect to a device

// Connect to the device
final connectedDevice = await ClassicBluetooth().connect(device);
print('Connected: ${connectedDevice.name}');

3. Disconnect

await ClassicBluetooth().disconnect();

ESC command usage

ESC commands are widely used by thermal receipt printers. See the ESC command reference for details.

Basic printing

import 'package:psdk_fruit_esc/psdk_fruit_esc.dart';

final esc = ESC.generic(connectedDevice);
await esc
  .initialize()
  .align(Align.center)
  .text('收银小票')
  .align(Align.left)
  .text('商品A x1  ￥29.90')
  .cut()
  .write();

Receipt printing example

final esc = ESC.generic(connectedDevice);
await esc
  .initialize()
  // Title
  .align(Align.center)
  .textSize(width: 2, height: 2)
  .bold(true)
  .text('XX 便利店')
  .bold(false)
  .textSize(width: 1, height: 1)
  .text('订单号: 20240115001')
  .text('================================')
  // Product list
  .align(Align.left)
  .text('可乐 500ml    x2    ￥6.00')
  .text('薯片 大包     x1    ￥8.50')
  .text('--------------------------------')
  // Total
  .textSize(width: 1, height: 2)
  .text('合计: ￥14.50')
  .textSize(width: 1, height: 1)
  // QR code
  .align(Align.center)
  .qrcode('https://shop.example.com', size: 5)
  .text('扫码关注店铺')
  .feed(3)
  .cut()
  .write();

Print an image

import 'dart:ui' as ui;

// Load an image
final image = await loadImage('assets/logo.png');

final esc = ESC.generic(connectedDevice);
await esc
  .initialize()
  .image(EscImage(image: image))
  .feed(3)
  .cut()
  .write();

CPCL command usage

CPCL commands are used by portable label printers. See the CPCL command reference for details.

Basic printing

import 'package:psdk_fruit_cpcl/psdk_fruit_cpcl.dart';

final cpcl = CPCL.generic(connectedDevice);
await cpcl
  .page(CPCLPage(width: 576, height: 400))
  .text(CPCLText(x: 50, y: 50, content: '商品标签'))
  .barcode(CPCLBarcode(x: 50, y: 150, content: '1234567890'))
  .print()
  .write();

Complete label example

final cpcl = CPCL.generic(connectedDevice);
await cpcl
  .page(CPCLPage(width: 576, height: 400))
  // Title
  .center()
  .text(CPCLText(
    x: 0, y: 30,
    font: 4, size: 2,
    content: '商品标签',
  ))
  // Product information
  .left()
  .text(CPCLText(x: 30, y: 100, content: '名称: 有机苹果'))
  .text(CPCLText(x: 30, y: 140, content: '规格: 500g/袋'))
  .text(CPCLText(x: 30, y: 180, content: '价格: ￥25.90'))
  // Barcode
  .barcode(CPCLBarcode(
    x: 100, y: 230,
    type: CPCLBarcodeType.code128,
    height: 60,
    content: '6901234567890',
  ))
  // QR code
  .qrcode(CPCLQRCode(
    x: 400, y: 100,
    content: 'https://example.com',
  ))
  .print()
  .write();

TSPL command usage

TSPL commands are used by label and barcode printers. See the TSPL command reference for details.

Basic printing

import 'package:psdk_fruit_tspl/psdk_fruit_tspl.dart';

final tspl = TSPL.generic(connectedDevice);
await tspl
  .page(TPage().width(60).height(40))
  .cls()
  .text(TText().x(50).y(50).content('标签内容'))
  .print(1)
  .write();

Complete label example

final tspl = TSPL.generic(connectedDevice);
await tspl
  .page(TPage().width(60).height(40))
  .gap(3)
  .direction(Direction.up)
  .cls()
  // Title
  .text(TText()
    .x(180).y(30)
    .font('TSS24.BF2')
    .xMulti(2).yMulti(2)
    .content('商品标签'))
  // Separator line
  .bar(TBar().x(30).y(80).width(420).height(2))
  // Product information
  .text(TText().x(30).y(100).content('品名: 有机苹果'))
  .text(TText().x(30).y(140).content('规格: 500g/袋'))
  .text(TText().x(30).y(180).content('价格: ￥25.90'))
  // Barcode
  .barcode(TBarcode()
    .x(100).y(220)
    .type('128')
    .height(60)
    .content('6901234567890'))
  // QR code
  .qrcode(TQRCode()
    .x(350).y(100)
    .cellWidth(4)
    .content('https://example.com'))
  .print(1)
  .write();

Listen for printer responses

connectedDevice.received.listen((data) {
  print('Printer response: $data');
  // Parse printer status, Query results, etc.
});

Error handling

try {
  await cpcl.write();
  print('Print successful');
} on BluetoothException catch (e) {
  print('Bluetooth error: ${e.message}');
} on PrinterException catch (e) {
  print('Printer error: ${e.message}');
} catch (e) {
  print('Unknown error: $e');
}

BLE usage (iOS/macOS)

import 'package:psdk_bluetooth_ble/psdk_bluetooth_ble.dart';

// Initialize
final ble = BleBluetooth();

// Scan for devices
await ble.startDiscovery();

// Listen for discovered devices
ble.discovered().listen((devices) {
  print('Found ${devices.length} devices');
});

// Connect to a device
final connectedDevice = await ble.connect(device);

// Disconnect
await ble.disconnect();

Example projects

For complete examples, see:

• dart-example
• psdk-examples