mimaki/webui

HPGL Plotter Web UI

Flask web interface for uploading HPGL files, previewing and transforming them (flip, rotate, scale, center), and sending to the plotter. Intended to run on a Raspberry Pi connected to the plotter via USB.

Setup (Raspberry Pi / Linux Mint / Debian)

From the project root (mimaki/), install dependencies. On Debian-based systems Python is externally managed (PEP 668), so use:

pip install --break-system-packages -r webui/requirements.txt

Then copy config.example.ini to config.ini and set the plotter port etc. (optional).

cp config.example.ini config.ini

Edit config.ini to set the plotter port (e.g. /dev/ttyUSB0) and optionally web UI port/host.

Run

From the project root (mimaki/):

python webui/app.py

Then open http://localhost:5000 (or http://<raspi-ip>:5000 from another device). Host is 0.0.0.0, port 5000 (see config.ini).

For production with gunicorn: pip install --break-system-packages gunicorn then gunicorn -w 1 -b 0.0.0.0:5000 "webui.app:app".

Usage

File tab

1. Upload – Choose an .hpgl or .plt file. It is validated and stored in webui/uploads/.
2. Preview – The drawing is converted to SVG and shown in the browser.
3. Transform – Flip, Rotate 90° / 180°, Scale + / −, Center, Scale to bounds. Each action updates the stored program and the preview.
4. Print – Sends the current (transformed) program to the plotter: scale to fit, center, then write HPGL to serial.

Text tab

1. Type text, select a font (from font/ or .git/font/, e.g. Melange-Bold.otf), set size (pt), then Generate HPGL.
2. The generated HPGL becomes the current program; use the same Preview, Transform, and Print as in the File tab.

Fonts: put .otf or .ttf files in the project font/ folder (or they are read from .git/font/ if present). The Text tab requires matplotlib (pip install matplotlib).

API

• POST /api/upload – Upload HPGL file (form field file).
• GET /api/svg – Get current program as SVG (query: width, height).
• POST /api/transform – Body: {"action": "flip"|"rotate"|"scale"|"centralize", "angle": 90, "factor": 1.25}.
• POST /api/print – Send current program to plotter.
• GET /api/status – has_file, filename, plotter_ready.

Session is used to keep the current file path; no database.