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Understanding Thermal Printers and How to Use it with ESP32

89

2025-09-03 | By Rinme Tom

License: General Public License Printer Enclosures Thermal Imaging Arduino ESP32

Project Overview

Build a compact, IoT-capable thermal printer using an ESP32 and a PNP-500 thermal printer module. This versatile system can print receipts, QR codes, barcodes, images, and invoices — ideal for smart home displays, DIY POS, or IoT data logs.

ESP32 thermal printer

Objectives

  • Demonstrate UART/TTL communication and ESC/POS print commands with ESP32.

  • Implement printing of images, QR codes, barcodes, and formatted invoices.

  • Manage power supply considerations and print quality tuning.

  • (Optional) Add wireless controls (e.g., via Wi-Fi app or MQTT) for IoT integration.

Features

  • Text Printing: Custom messages, timestamps, sensor data.

  • Barcode & QR Printing: Scannable codes for asset tags, links, or user authentication.

  • Image Printing: Convert small bitmap logos or icons using image2cpp a tool.

  • Invoice Formatting: Styled receipts with headers, totals, and footers (e.g., GST invoice).

  • Custom Controls: Trigger prints via onboard buttons or software commands.

Components & Tools Required

  • Hardware:

    • ESP32 development board

    • Thermal printer (PNP-500 or RS203)

    • Power supply: 5–9 V DC (recommended ≥ 2 A for the printer)

    • Breadboard, jumper wires, optional push buttons/pull-up resistors

  • Software & Libraries:

    • Arduino IDE (ESP32 board support)

    • ESC/POS command implementation

    • image2cpp tool for bitmap → code conversion

ESP32 Circuit Diagram

Wiring & Circuit Setup

  1. Power: Use a dedicated 5V 2A (or higher) supply for the printer; share ground with ESP32.

  2. Connections:

    • Thermal Printer RX → ESP32 TX (e.g., GPIO 17)

    • Thermal Printer TX → ESP32 RX (e.g., GPIO 16)

    • Optional: Add pull-up resistors on TX/RX lines to reduce noise.

  3. Status indicators:

    • LED and button: show printer status or trigger print jobs.

What Makes This Project Stand Out

  • Educational Depth: Covers thermal printing fundamentals, UART comms, ESC/POS commands, and bitmap processing.

  • Practical Utility: Applications in receipts, IoT alerts, asset tracking, and smart displays.

  • Flexibility: Modular – easy to customise or extend with sensors and connectivity.

  • Professional Presentation: Includes schematics, code, wiring diagrams, and demo prints.

    You can get the complete details from the orginal source of ESP32 Thermal Printer Interface

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