ix500

func (*Device) Close ¶

func (d *Device) Close() error

Close releases the USB interface and closes the device file.

After calling Close, the Device must not be used. This releases interface 0 (the only interface used by the iX500) and closes the underlying file descriptor.

func (*Device) Read ¶

func (d *Device) Read(p []byte) (n int, err error)

Read implements io.Reader by performing a USB bulk IN transfer.

It transfers up to len(p) bytes from the scanner to the host via the IN endpoint (endpoint 1). The transfer uses a 3-second timeout and blocks until data is available or the timeout expires. The number of bytes actually received is returned.

func (*Device) Write ¶

func (d *Device) Write(p []byte) (n int, err error)

Write implements io.Writer by performing a USB bulk OUT transfer.

It transfers all of p from the host to the scanner via the OUT endpoint (endpoint 2). The transfer uses a 3-second timeout and blocks until all data is sent or the timeout expires. Returns the number of bytes written.

func (*Scanner) Close ¶

func (s *Scanner) Close() error

Close releases any resources associated with the scanner and closes the underlying USB device.

func (*Scanner) Initialize ¶

func (s *Scanner) Initialize(ctx context.Context) error

Initialize prepares the scanner hardware for operation.

This method executes the required SCSI command sequence to configure the scanner:

1. INQUIRY - verify device identification
2. SEND DIAGNOSTIC (preread) - set 600 dpi resolution
3. MODE SELECT (multiple) - configure ADF, double-feed detection, color dropout, buffering, etc.
4. SET WINDOW - define front and back scan areas
5. SEND - transfer lookup tables and quantization tables
6. SCANNER_CONTROL (lamp on) - activate scanning lamp
7. GET_HW_STATUS - verify hardware readiness

The full command sequence runs on every call. It is safe to call again after hardware errors or firmware resets to restore the scanner to a known state.

func (*Scanner) IsButtonPressed ¶

func (s *Scanner) IsButtonPressed(ctx context.Context) (bool, error)

IsButtonPressed checks if the scan button is currently pressed. It performs a non-blocking check of the hardware status.

func (*Scanner) Scan ¶

func (s *Scanner) Scan(ctx context.Context) iter.Seq2[*Page, error]

Scan performs a complete duplex scan operation, yielding pages as they are scanned.

This method returns an iterator that yields *Page values for each side of each sheet. The scanning sequence for each sheet is:

1. OBJECT POSITION - load paper from hopper
2. SCAN - initiate scanning of both sides
3. READ (vendor-specific) - query pixel dimensions
4. For each side (front=0, back=1): - Issue ric commands until data is ready - Execute READ commands to stream image data - Decode RGB data into image.Image - Yield the Page immediately

The iteration continues until the hopper is empty (ErrHopperEmpty), an error occurs, or the context is cancelled. Pages are yielded in hardware scan order: Sheet N Front, Sheet N Back, Sheet (N-1) Front, etc. The iX500 scans the last sheet first. Callers can use Page.Sheet and Page.Side to reorder as needed.

package main

import (
	"context"
	"fmt"
	"image/jpeg"
	"os"
	"path/filepath"

	"thde.io/ix500"
)

func main() {
	ctx := context.Background()

	dev, err := ix500.FindDevice()
	if err != nil {
		fmt.Fprintln(os.Stderr, "scanner not found:", err)
		return
	}

	scn := ix500.New(dev, &ix500.Options{
		Resolution: ix500.DPI300,
		ScanMode:   ix500.Duplex,
	})
	defer scn.Close()

	if err := scn.Initialize(ctx); err != nil {
		fmt.Fprintln(os.Stderr, "initialization failed:", err)
		return
	}

	if err := scn.WaitForButton(ctx); err != nil {
		fmt.Fprintln(os.Stderr, "button wait failed:", err)
		return
	}

	outDir := os.TempDir()
	pageNum := 0
	for page, err := range scn.Scan(ctx) {
		if err != nil {
			fmt.Fprintln(os.Stderr, "scan error:", err)
			return
		}

		path := filepath.Join(outDir, fmt.Sprintf("page-%03d.jpg", pageNum))
		f, err := os.Create(path)
		if err != nil {
			fmt.Fprintln(os.Stderr, "create file:", err)
			return
		}
		if encErr := jpeg.Encode(f, page, &jpeg.Options{Quality: 75}); encErr != nil {
			_ = f.Close()
			fmt.Fprintln(os.Stderr, "encode:", encErr)
			return
		}
		_ = f.Close()

		bounds := page.Bounds()
		fmt.Printf("saved %s (%dx%d, sheet=%d, side=%d)\n",
			filepath.Base(path), bounds.Dx(), bounds.Dy(), page.Sheet, page.Side)
		pageNum++
	}

	fmt.Printf("scan complete, %d pages\n", pageNum)
}

func (*Scanner) WaitForButton ¶

func (s *Scanner) WaitForButton(ctx context.Context) error

WaitForButton blocks until the scan button is pressed or the context is cancelled. It polls the scanner status at the interval specified in Options.ButtonPollInterval.