GitHub - seamusc/papermono-shopping-list: E-paper shopping list for the M5Stack PaperMono, with a FastAPI server and phone web UI

What it shows on the PaperMono E-paper refreshes handled properly. Taps, scrolling and typing use fast partial updates with no flash. A full refresh is forced after every 10 partial updates to keep ghosting down and protect the panel. Greys are drawn as 1-bit dot patterns, so they look the same under both refresh modes. A usable touch UI on e-paper. Tap, swipe and the side buttons all work. There's an on-screen keyboard that only redraws the parts that change as you type, and it suggests items you've added before. Low-power networking. Wi-Fi is on only while syncing: every hour, sooner if you tap the screen and the last sync is more than 5 minutes stale, and straight after an edit. Everything else works offline, and edits are queued on flash until the next sync. Tidy power handling. Power-button shutdown, with a deep-sleep fallback for when USB power stops the power IC switching off. The device turns itself off at a safe battery voltage. The frontlight is off by default. Documented bring-up. The power IC, IO expander, panel and touch controller are brought up in a known-good order. docs/hardware.md has the pin map, I²C addresses and the quirks found along the way. How it works The device shows the list grouped by aisle, in the order you walk the shop. Tap an item to tick it off, or add one with the on-screen keyboard. Everyone else adds things from their phone. A small server in between stores the list. It remembers which aisle every item belongs to and can optionally sort brand-new items into the right aisle with Claude. flowchart LR device["PaperMono<br/>(firmware/)"] -- "Wi-Fi, hourly or on tap<br/>and after each edit" --> server phone["Phone browser"] -- HTTP --> server subgraph server["Server (server/)"] api["FastAPI + SQLite"] web["Web UI"] end api -. "new item names only" .-> claude["Claude Code CLI<br/>(optional)"] Loading Grouped by aisle, in walking order. You set the aisle order once from the phone, and both screens follow it. Works offline. The list, suggestions, ticking off and adding all work without a connection, including in a shop with no signal. Remembers your items. Every name you've added goes into a catalog that drives suggestions on both the device and the phone. Optional auto-sorting. The first time the server sees a name, it can send it to Claude to file it under an aisle. If you move an item to a different aisle by hand, that correction sticks. Repository layout firmware/ PlatformIO project for the PaperMono (C++ / Arduino) server/ FastAPI server, SQLite store, phone web UI, tests docs/ Hardware notes, architecture, API, build and deploy guides, design notes Quick start 1. Run the server cd server python3 -m venv .venv && .venv/bin/pip install -e . SHOPPING_LIST_CLASSIFIER=none .venv/bin/uvicorn shopping_list.main:app --host 0.0.0.0 --port 8000 Open http://<server-ip>:8000/ on your phone, tap Aisles, and add your shop's aisles in the order you walk them. See docs/server.md for systemd and Docker deployment and for turning on auto-sorting. 2. Build and flash the firmware You need PlatformIO and a PaperMono connected over USB-C. cd firmware cp src/secrets.example.h src/secrets.h # set Wi-Fi SSID/password and the server URL pio run -t upload Back up your device's flash before the first flash. It holds that unit's factory calibration data. docs/firmware.md covers the backup, download mode and flashing from a browser. Documentation Doc What's in it Hardware notes Pin map, I²C devices, bring-up sequence, display, touch and power details; reusing the drivers Firmware Building, configuring, flashing and recovering the device; using it; troubleshooting Architecture Components, data model, the sync protocol, offline behaviour, display refresh policy Server Running and deploying the server, configuration, auto-sorting, security HTTP API Every endpoint, request and response Design notes Where the firmware came from, decisions and trade-offs, known limitations Status A personal project, running on one device at home. It works, but it isn't a product. There's no on-device Wi-Fi setup (credentials are compiled in), no authentication on the server (keep it on your LAN or behind an authenticating reverse proxy), and only the PaperMono C153 has been tested. See known limitations. Author Built by Seamus Cawley, who builds Bronto, the logging and observability platform, by day. Credits The firmware's board support, e-paper and touch drivers, keyboard layout and widget style are adapted from MonoMesh by andrecolz, an independent Meshtastic-compatible firmware for the same hardware. docs/design-notes.md lists exactly what was reused. License GNU General Public License v3.0, the same license as MonoMesh, which parts of the firmware derive from.