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POS Peripherals

Setup, configuration, and integration for cash drawers, customer displays, and barcode scanners.

Cash Drawers​

Supported Models​

BrandModelInterface
APGVasarioPrinter-driven (RJ12)
StarCD3-1616Printer-driven
MMFVal-u LinePrinter-driven, USB

Configuration​

# config/hardware/cash_drawers.yaml
cash_drawers:
  - id: "drawer_001"
    name: "Register 1"
    type: "printer_driven"
    printer_id: "printer_001"
    pin: 2
    expected_float: 200.00

  - id: "drawer_002"
    name: "Register 2"
    type: "usb"
    vendor_id: "0x0416"
    product_id: "0x0001"
    expected_float: 200.00

Cash Drawer Operations​

// src/hardware/cash_drawer.rs
pub struct CashDrawerService {
    drawers: HashMap<String, CashDrawer>,
}

impl CashDrawerService {
    pub async fn open_drawer(&self, drawer_id: &str) -> Result<()> {
        let drawer = self.drawers.get(drawer_id)
            .ok_or(Error::DrawerNotFound)?;

        match drawer.drawer_type {
            DrawerType::PrinterDriven { printer_id, pin } => {
                let printer = printer_service.get(&printer_id)?;
                printer.open_cash_drawer(pin).await?;
            }
            DrawerType::USB { vendor_id, product_id } => {
                let device = usb::open_device(vendor_id, product_id)?;
                device.send_open_command().await?;
            }
        }

        // Log drawer open event
        audit_service.log(AuditEvent::CashDrawerOpened {
            drawer_id: drawer_id.to_string(),
            user_id: current_user_id(),
            timestamp: Utc::now(),
        }).await?;

        Ok(())
    }

    pub async fn check_status(&self, drawer_id: &str) -> Result<DrawerStatus> {
        let drawer = self.drawers.get(drawer_id)
            .ok_or(Error::DrawerNotFound)?;

        // Some drawers support status check
        match drawer.drawer_type {
            DrawerType::PrinterDriven { printer_id, .. } => {
                let printer = printer_service.get(&printer_id)?;
                let status = printer.get_drawer_status().await?;
                Ok(if status.is_open { DrawerStatus::Open } else { DrawerStatus::Closed })
            }
            _ => Ok(DrawerStatus::Unknown),
        }
    }
}

Customer Displays​

Configuration​

# config/hardware/customer_displays.yaml
customer_displays:
  - id: "display_001"
    name: "Register 1 Display"
    type: "pole_display"
    connection:
      type: "serial"
      port: "/dev/ttyUSB0"
      baud_rate: 9600
    width: 20
    lines: 2

  - id: "display_002"
    name: "Register 2 Display"
    type: "lcd_screen"
    connection:
      type: "usb"
      vendor_id: "0x0801"
      product_id: "0x0001"

Pole Display Integration​

// src/hardware/customer_display.rs
pub struct CustomerDisplayService {
    displays: HashMap<String, CustomerDisplay>,
}

impl CustomerDisplayService {
    pub async fn show_welcome(&self, display_id: &str) -> Result<()> {
        let display = self.get_display(display_id)?;

        display.clear().await?;
        display.write_line(0, "Welcome!").await?;
        display.write_line(1, "Ready to serve you").await?;

        Ok(())
    }

    pub async fn show_item(&self, display_id: &str, item: &OrderItem) -> Result<()> {
        let display = self.get_display(display_id)?;

        display.clear().await?;
        display.write_line(0, &truncate(&item.name, display.width)).await?;
        display.write_line(1, &format!("${:.2}", item.total)).await?;

        Ok(())
    }

    pub async fn show_total(&self, display_id: &str, total: f64) -> Result<()> {
        let display = self.get_display(display_id)?;

        display.clear().await?;
        display.write_line(0, "Total:").await?;
        display.set_emphasis(true).await?;
        display.write_line(1, &format!("${:.2}", total)).await?;
        display.set_emphasis(false).await?;

        Ok(())
    }

    pub async fn show_thank_you(&self, display_id: &str) -> Result<()> {
        let display = self.get_display(display_id)?;

        display.clear().await?;
        display.write_line(0, "Thank You!").await?;
        display.write_line(1, "Please come again").await?;

        // Reset to welcome after delay
        tokio::time::sleep(Duration::from_secs(5)).await;
        self.show_welcome(display_id).await?;

        Ok(())
    }
}