sk58_printer 0.2.2

Flutter library for SK58 thermal printer via Bluetooth. Supports Android and Linux.

Changelog

0.2.2

Added

• Realistic Label Preview: Image demo now shows a realistic label preview with:
  • Dead zone visualization (grey "NO PRINT" area at top)
  • Printable area (white)
  • Top margin indicator (blue)
  • Label size presets (40x15, 50x25, 50x30, 40x30mm)
  • Adjustable dead zone slider (0-8mm)
  • Fit warning showing exact printable dimensions
• feedAfter parameter: New feedAfter parameter in printImage() to control line feed after image
  • Default false for labels (no extra whitespace)
  • Set true for continuous paper
• Documentation: Added printer specifications and dead zone info to README

Changed

• Image preview now scales correctly with label size
• Improved label printing workflow in example app

0.2.1

Added

• Label Feed Offset: New extraFeedDots parameter for fine-tuning label positioning
• New label commands:
  • formFeed() - Simple FF (0x0C) command
  • printAndPeel() - GS FF (0x1D 0x0C) - recommended for SK58
  • feedDots(int) - ESC J n for precise dot feeding
  • feedLines(int) - ESC d n for line feeding
  • feedToStartPosition - FS ( L fn=67 alternative command
• Label Mode in Image Demo: Option to use label paper mode with feed offset adjustment
• Feed Test Buttons: New test card in Labels demo to try different feed methods

Fixed

• Label alignment fix: feedToNextLabel() now uses GS FF (0x1D 0x0C) command
  • Tested and confirmed working on SK58 printers
  • Fixes issue where 3 labels were printed on 2 physical labels
  • Labels now correctly advance to the next label gap

Changed

• LabelCommands.feedToNextLabel now uses GS FF (0x1D 0x0C) instead of FF for reliable label feeding
• printAndPeel() is now an alias for feedToNextLabel() (same GS FF command)

0.2.0

Added

• Band Mode for Image Printing: New bandMode parameter in printImage() for reliable image printing on mobile printers and small labels
  • Uses ESC * 33 (24-dot double density) command
  • Sends image in 24-line bands instead of all at once
  • Recommended for printers with limited buffers

Fixed

• Image printing on mobile thermal printers now works correctly
• Images no longer appear stretched or corrupted on small labels (e.g., 40x15mm)

Changed

• toLineByLineCommands() in ProcessedImage now uses ESC * 33 instead of GS v 0 bands

0.1.0

• Initial release
• Bluetooth scanning for SK58 printers
• Connect/disconnect functionality
• Print text with alignment and styles (bold, underline, sizes)
• Print QR codes
• Print barcodes (Code128, EAN-13, UPC-A, Code39)
• Print images with Floyd-Steinberg dithering
• Label templates (Sk58Label, Sk58TwoColumnLabel)
• Fluent builder pattern for complex prints
• Support for Android and Linux platforms