Thermal Printer Service - Annas Tri Widagdo

[01]

Overview

Thermal Printer Service is a native Kotlin Android PrintService for selected 58 mm and 80 mm Bluetooth thermal-printer workflows.

It converts Android PDF print jobs into monochrome ESC/POS raster data and sends them over an RFCOMM/SPP connection.

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Implemented Android PrintService discovery and print-job handling in Kotlin.
Built the PDF-to-bitmap and monochrome ESC/POS raster conversion pipeline.
Added Bluetooth permissions, background execution, cancellation, chunked writes, and retry handling.
Created reusable printer profiles, calibration controls, and error states for 58 mm and 80 mm configurations.

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PdfRenderer rasterizes pages before 24-dot double-density ESC/POS encoding.
Configured widths are 432 dots for 58 mm and 576 dots for 80 mm at 203 dpi.
Bluetooth writes use chunks up to 1,024 bytes with four attempts at 0, 200, 500, and 1,000 ms delays.
Printer profiles persist eight configuration attributes as JSON in SharedPreferences.

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FIG.02Documented printer-profile configuration and Bluetooth setup flow.

[04.V // VIDEO DEMO]Video Demonstration Record

Demonstration of the Android PrintService workflow output to a Bluetooth ESC/POS thermal printer.

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[06]

Completed Android service

Source repository or production deployment is private.