Hardware Integration: Microtec POS

Microtec POS is designed to interface with a variety of retail and restaurant hardware. This document describes the architecture of these integrations.

1. Printing System (ESC/POS)

The printing system is built on the ESC/POS standard, supporting thermal receipt printers and impact kitchen printers.

EscPrintingOperationBloc

This BLoC orchestrates all printing tasks:

• Automatic Routing: Orders are routed to different printers based on product groups (e.g., "Drinks" to the Bar, "Main Course" to the Kitchen).
• Templates: Uses LocalPrintTemplateDto to define what information appears on receipts versus kitchen slips.
• Multi-Printer Support: A single transaction can trigger multiple print jobs (e.g., one customer receipt and two kitchen copies).

Communication

• Network Printers: Uses EscPrinterSocketOperation to communicate over TCP/IP (port 9100).
• USB/Bluetooth: Handled via the pos_printer_manager package (integrated as a local dependency).

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2. Payment Terminals (Bank/Visa)

Integration with physical payment terminals ensures that card transactions are automatically reconciled in the POS.

OrderPayByDeviceOperationBloc

• Workflow: When a "Card" payment is initiated, the POS sends the amount to the terminal via a local network or serial connection.
• Verification: The POS waits for a success signal from the terminal before finalizing the OrderModel and emitting the success state.
• Failure Recovery: If the terminal transaction fails, the BLoC provides the failure reason and allows the cashier to retry or change the payment method.

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3. Peripheral Devices

Barcode Scanners

• Integration: Handled via custom listeners that capture HID (Keyboard) input and standard camera-based scanning via the flutter_barcode_scanner package.
• Logic: Scanned barcodes are matched against the local ItemBarcode store to instantly add products to the cart.

Customer Display Systems (CDS)

• Multi-Window (Windows): For dual-screen setups, the app launches a secondary window using desktop_multi_window.
• Tablet CDS: For secondary tablets, real-time data is pushed via gRPC to ensure the customer sees item updates and totals instantly.

Weighing Scales

• Logic: Integrated via ScalesSyncBloc and specialized managers to read weight data directly into the POS, automatically calculating prices for "Weight-based" products.

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For details on the networking protocols used for these devices, see COMMUNICATION_PROTOCOLS.md.