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Build and push server image / build-and-push (push) Successful in 42s
The old estimate used a single linear percent/second rate from the current discharge cycle's battery_history, which resets to empty on every recharge -- so "not enough data yet" kept showing up despite the frame having plenty of history overall, and the rate it did compute was tied to whatever refresh interval produced it (changing the interval didn't move the estimate until enough new history accumulated under the new setting). Now pulls the last 100 rows from the permanent battery_log table instead, and averages the *per-wake* percent drop (not per-second) -- recharge jumps are skipped rather than counted as negative drain, flat/zero-drop wakes still count so the rate isn't overstated, and more recent steps are weighted more heavily. The per-wake rate then converts to wall-clock time using the frame's current refresh_interval_s and quiet-hours settings, so halving the refresh interval roughly halves the estimate immediately, and quiet hours correctly stretches it out (fewer wakes/day at the same per-wake cost).
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.