PrintGrandma

An automatic thermal printer system that receives photos via Telegram and prints them — built for my grandmother, inspired by the Yayagram project (Instructables guide).

My grandmother can't read, doesn't own a smartphone, and needs the simplest possible experience: family members send a photo to the Telegram bot, and it prints automatically — no interaction needed on her end.

Printed result	Telegram bot

Features

• Telegram bot — receives photos from authorised family members and queues them for printing.
• Thermal printer interface — polls the queue and sends images to a USB ESC/POS thermal printer at the correct width.
• Multi-process architecture — the bot and printer run as independent processes; if one crashes the other shuts down cleanly.

Planned features

• Sound/light notification when a photo arrives.
• Voice message playback.

Requirements

• Python 3.10–3.13
• uv package manager
• A USB ESC/POS thermal printer
• A Telegram bot token (obtain via @BotFather)

Installation

# Clone the repository
git clone https://github.com/your-user/PrintGrandma.git
cd PrintGrandma

# Install dependencies (creates .venv automatically)
uv sync

Configuration

Static configuration — config/config.yaml

telegram_bot:
  enable: true
  api: TELEGRAM_PRINTER_API_KEY   # name of the env var holding the bot token
  image_dir: received_images/
  allowed_users:
    - CHAT_ID_USER1               # name of an env var holding a chat ID

printer:
  enable: true
  image_width: 384                # pixels — match your printer head width
  idVendor: 0x6868
  idProduct: 0x0200
  profile: "Sunmi-V2"

Environment variables

Add the following to /etc/profile (or your preferred env file) so sudo -E picks them up:

export TELEGRAM_PRINTER_API_KEY="your-bot-token"
export CHAT_ID_USER1="123456789"

Run the helper script to verify everything is set before starting:

uv run python environmental_variables_check.py

Running

# sudo -E forwards the user's environment variables to the root process
sudo -E uv run python printgrandma.py

# Optional: point to a custom config file
sudo -E uv run python printgrandma.py --config /path/to/config.yaml

Development

# Install dev dependencies (ruff is included)
uv sync

# Lint
uv run ruff check .

# Format
uv run ruff format .

# Lint + auto-fix
uv run ruff check --fix .

License

MIT