Bleh!

<p align=center> <img width=320 src="./demo.jpg"/> </p>

Bleh! is a command-line utility to print images on the MXW01 Bluetooth thermal printer. It supports 1-bit (1bpp) and 4-bit (4bpp) printing, various dithering algorithms, PNG preview output, and direct communication with the printer via BLE.

Features

• Print PNG/JPG images (from file or stdin) in 1bpp or 4bpp mode
• Multiple dithering algorithms (Floyd-Steinberg, Bayer, Atkinson, etc.)
• Query printer status, battery, version, and more
• Output a PNG preview instead of printing (for integration or testing)
• Command-line interface with fine-grained options
• Works on Linux using BlueZ (via go-ble/ble)

Compiling

On a Linux system, run:

go get bleh

Then:

go build

If you want to be able to run it as a regular user, you'll need setcap:

sudo setcap cap_net_raw,cap_net_admin=eip ./bleh

Usage

bleh [options] <image_path or ->

Options

| Option | Description | | -------------------- | ----------------------------------------------------------------------------------- | | -i, --intensity | Print intensity (0-100) (default: 80) | | -m, --mode | Print mode: 1bpp or 4bpp (default: "1bpp") | | -d, --dither | Dither method: none, floyd, bayer2x2, bayer4x4, bayer8x8, bayer16x16, atkinson, jjn | | -s, --status | Query printer status | | -b, --battery | Query battery level | | -v, --version | Query printer version | | -p, --printtype | Query print type | | -q, --querycount | Query internal counter | | -E, --eject | Eject paper by N lines | | -R, --retract | Retract paper by N lines | | -o, --output | Output PNG preview instead of printing. If value is "-", writes PNG to stdout. | | <image_path or -> | Path to PNG/JPG image to print, or "-" for stdin |

Example

bleh -m 4bpp -d floyd ./myimage.png

Requirements

• Go 1.18+
• BlueZ on Linux (for BLE support)
• Dependencies listed in go.mod (see source)

License

This project is licensed under the terms of the GNU General Public License v3.0 or later. Parts of the code were ported from CatPrinterBLE and are licensed under the MIT License. See the LICENSE file for details.

Disclaimer: While a license was only added after the project’s initial commits, the current license applies retroactively to all previous commits of this repository.