frame/CLAUDE.md
2026-03-30 08:09:47 +01:00

2.9 KiB
Raw Blame History

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

What This Is

An e-ink photo frame that runs on a Raspberry Pi Zero 2W. It fetches photos from an Immich server, checks Home Assistant for presence (only displays when someone is home), and renders them on a Waveshare 7.3" 6-color e-Paper display (800x480, ACeP technology with Black/White/Yellow/Red/Blue/Green).

Deployment

./sync.sh          # rsync src/ to andras@192.168.0.81:~/frame/

On the Pi:

cd ~/frame
python3 display.py                          # default: photos of Me,Ruby
python3 display.py --album "Album Name"     # from specific album
python3 display.py -o 90                    # portrait mode (90° or 270°)
python3 display.py --saturation 1.5 --contrast 1.1 --gamma 0.85

Architecture

src/display.py — Entry point. Orchestrates the pipeline:

  1. Checks time (skips between midnight7am)
  2. Checks Home Assistant presence (skips if nobody home)
  3. Fetches a random photo from Immich (by people or album)
  4. Sends to e-ink display driver

src/lib/immich.py — Immich API client. Key behaviors:

  • PhotoHistory tracks displayed photos in photo_history.json to avoid repeats (resets after 7 days)
  • _pick_weighted_random() biases selection: 50% chance favorites, 50% chance recent (last 7 days), otherwise random
  • Filters photos by orientation (portrait/landscape) based on EXIF data including rotation tags
  • Downloads preview-size thumbnails, not originals

src/lib/homeassistant.py — Simple Home Assistant REST client for presence detection.

src/lib/waveshare_epd/epd7in3e.py — Modified Waveshare driver. The getbuffer() method handles the full image pipeline:

  • Center-crops to 800x480 (or 480x800)
  • Enhances saturation/contrast/gamma for e-ink (defaults: saturation=1.4, contrast=1.2, gamma=0.9)
  • Atkinson dithering to 6-color palette using numba JIT
  • Packs into 4-bit-per-pixel buffer (two pixels per byte)

src/lib/waveshare_epd/epdconfig.py — GPIO/SPI hardware config. Critical: PWR pin is BCM 27 (not default 18).

src/lib/progress.py — Simple terminal progress bar.

Key Constraints

  • Always call epd.sleep() after display — the driver uses a try/finally pattern for this
  • Display refresh takes 12-15 seconds — the BUSY pin polling handles this
  • No test suite — this is a hardware project; test by deploying to the Pi
  • Dependencies on Pi: python3-pil python3-opencv python3-numba python3-smbus spidev gpiozero
  • Config via environment variables: IMMICH_URL, IMMICH_API_KEY, HA_URL, HA_TOKEN (with hardcoded defaults in display.py)
  • Uses only stdlib urllib — no requests library; the Immich client uses urllib.request directly
  • sys.path.append is used to add lib/ to the path from display.py