tfaour
b9649c35ec
The panel driver now splits writing a frame into its SPI buffer (epd_write_frame(), which also computes a CRC32 as it streams) from actually triggering the physical refresh (epd_turn_on_display()). frame_client.c compares the new CRC against the last one that was actually refreshed (persisted in NVS) and skips the refresh entirely when they match -- e.g. a reboot redisplaying the same photo before the server's refresh interval elapsed no longer causes a visible flash for no visual change. Also reorders the per-wake fetch cycle: the image fetch (15s timeout) now goes before the config check (3s timeout), instead of after. The config check's tighter timeout was intermittently tripping on connection-setup latency that's common on the first request after waking from a long deep sleep (e.g. stale ARP); putting the more tolerant request first absorbs that latency, and the config check then rides the connection it already warmed up.
ESPresso Frame
A DIY e-ink photo frame: an ESP32-C6 pulls photos from your Immich library and displays them on a 7.3" full-color e-paper panel, waking on a timer to refresh and spending the rest of its time in deep sleep.
- No cables to a computer, no SD card shuffling. Provisioning is a captive portal with a QR code drawn on the panel itself -- scan, join, fill in your WiFi and server address, done.
- The frame never decodes an image. A small self-hosted server does all the work (pulling from Immich, cropping, dithering, packing into the panel's exact pixel format) and hands the device a stream it can write straight to SPI. The ESP32-C6 has no PSRAM and not much SRAM to spare -- keeping it a dumb display client is what makes that workable.
- Crops toward faces, not just the center, using face bounding boxes Immich already computed for its own People feature -- no bundled face detector.
- Refresh interval and album are configurable from a web UI, no reflashing needed to change them.
Hardware
- ESP32-C6 dev board (8MB flash)
- Waveshare 7.3" E Ink Spectra 6 (E6) panel -- 800x480, 6-color, SPI
See docs/hardware.md for wiring and
docs/architecture.md for how the two halves talk
to each other.
Getting started
server/-- run the FastAPI server first (Docker Compose, points at your Immich instance). Seeserver/README.md.firmware/-- build and flash the ESP32-C6, then scan the QR codes it draws on first boot to provision it. Seefirmware/README.md.
Repo layout
firmware/ ESP-IDF project for the ESP32-C6
server/ FastAPI server: Immich -> crop/dither/pack -> the frame
docs/ Wiring and architecture notes
License
MIT -- see LICENSE. A few small pieces of vendored
third-party code (a QR code generator, a bitmap font table) keep their
own permissive licenses; see LICENSE for details.
Built with substantial assistance from Claude Code.