SCALE_EN.md

Scale Module

Electronic scale integration for iMin POS devices (Android 13+).

Installation

Add to your pubspec.yaml:

dependencies:
  imin_hardware_plugin: ^1.0.0

Then run:

flutter pub get

Import

import 'package:imin_hardware_plugin/imin_hardware_plugin.dart';

The plugin exports IminScaleNew class for electronic scale operations (Android 13+).

Features

• Connect to scale service
• Real-time weight data streaming
• Zero and tare operations
• Price calculation
• Unit conversion
• Device information and diagnostics

API Reference

Connect to Service

bool success = await IminScaleNew.connectService();

Get Service Version

String version = await IminScaleNew.getServiceVersion();

Get Firmware Version

String version = await IminScaleNew.getFirmwareVersion();

Start Getting Data

bool success = await IminScaleNew.getData();

Stop Getting Data

bool success = await IminScaleNew.cancelGetData();

Listen to Scale Events

StreamSubscription<ScaleEvent> subscription = IminScaleNew.eventStream.listen((event) {
  if (event.isWeight) {
    final data = event.data as ScaleWeightData;
    print('Net: ${data.net} kg');
    print('Tare: ${data.tare} kg');
    print('Stable: ${data.isStable}');
  } else if (event.isStatus) {
    final status = event.data as ScaleStatusData;
    print('Overload: ${status.overload}');
    print('Light weight: ${status.isLightWeight}');
  } else if (event.isPrice) {
    final price = event.data as ScalePriceData;
    print('Unit price: ${price.unitPrice}');
    print('Total price: ${price.totalPrice}');
  } else if (event.isError) {
    print('Error code: ${event.data}');
  } else if (event.isConnection) {
    final conn = event.data as ScaleConnectionData;
    print('Connected: ${conn.connected}');
  }
});

Zero Operation

await IminScaleNew.zero();

Tare Operation

await IminScaleNew.tare();

Digital Tare

await IminScaleNew.digitalTare(100); // Tare 100g

Set Unit Price

await IminScaleNew.setUnitPrice('9.99');

Set Unit

await IminScaleNew.setUnit(ScaleUnit.kg);

Available units:

• ScaleUnit.g - Grams
• ScaleUnit.g100 - 100 grams
• ScaleUnit.g500 - 500 grams
• ScaleUnit.kg - Kilograms

Device Operations

// Read accelerometer data
List<int> accelData = await IminScaleNew.readAcceleData();

// Read seal state
int sealState = await IminScaleNew.readSealState();

// Get calibration status
int calStatus = await IminScaleNew.getCalStatus();

// Get calibration info
List<List<int>> calInfo = await IminScaleNew.getCalInfo();

// Restart scale
await IminScaleNew.restart();

Data Models

ScaleWeightData

class ScaleWeightData {
  final double net;        // Net weight in kg
  final double tare;       // Tare weight in kg
  final bool isStable;     // Weight is stable
}

ScaleStatusData

class ScaleStatusData {
  final bool overload;         // Scale overloaded
  final bool isLightWeight;    // Weight too light
  final bool clearZeroErr;     // Zero error
  final bool calibrationErr;   // Calibration error
}

ScalePriceData

class ScalePriceData {
  final String unitPrice;    // Unit price
  final String totalPrice;   // Total price
  final String unitName;     // Unit name
}

Example

import 'package:imin_hardware_plugin/imin_hardware_plugin.dart';

class ScaleExample extends StatefulWidget {
  @override
  _ScaleExampleState createState() => _ScaleExampleState();
}

class _ScaleExampleState extends State<ScaleExample> {
  bool _isConnected = false;
  bool _isGettingData = false;
  ScaleWeightData? _currentWeight;
  StreamSubscription<ScaleEvent>? _subscription;

  @override
  void initState() {
    super.initState();
    _listenToEvents();
    _connectService();
  }

  @override
  void dispose() {
    _subscription?.cancel();
    IminScaleNew.cancelGetData();
    super.dispose();
  }

  void _listenToEvents() {
    _subscription = IminScaleNew.eventStream.listen((event) {
      if (event.isWeight) {
        setState(() => _currentWeight = event.data as ScaleWeightData);
      } else if (event.isConnection) {
        final conn = event.data as ScaleConnectionData;
        setState(() => _isConnected = conn.connected);
      }
    });
  }

  Future<void> _connectService() async {
    final success = await IminScaleNew.connectService();
    if (success) {
      await Future.delayed(Duration(milliseconds: 500));
      _startGetData();
    }
  }

  Future<void> _startGetData() async {
    final success = await IminScaleNew.getData();
    setState(() => _isGettingData = success);
  }

  Future<void> _stopGetData() async {
    await IminScaleNew.cancelGetData();
    setState(() => _isGettingData = false);
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text('Connected: $_isConnected'),
        Text('Getting Data: $_isGettingData'),
        if (_currentWeight != null) ...[
          Text('Net: ${_currentWeight!.net.toStringAsFixed(3)} kg'),
          Text('Tare: ${_currentWeight!.tare.toStringAsFixed(3)} kg'),
          Text('Stable: ${_currentWeight!.isStable ? "✓" : "~"}'),
        ],
        ElevatedButton(
          onPressed: _isConnected ? () => IminScaleNew.zero() : null,
          child: Text('Zero'),
        ),
        ElevatedButton(
          onPressed: _isConnected ? () => IminScaleNew.tare() : null,
          child: Text('Tare'),
        ),
      ],
    );
  }
}

Notes

• Requires Android 13 or higher
• Connect to service before operations
• Weight data streams continuously when active
• Stop getting data when not needed
• Handle errors appropriately

Supported Devices

iMin devices with electronic scale support (Android 13+)