Creator of Tesserae — an open-source platform for e-paper dashboards. I build Python backends, embedded firmware, native macOS applications, and developer tooling.
Melbourne, Australia · Ex-ANZ (platform engineering & automation) · Open to full-stack, platform, and embedded-adjacent roles.
dmello.io · LinkedIn · dmellok@icloud.com
tesserae.ink · Documentation · Source
A self-hosted dashboard server for e-ink displays. Compose tile-based dashboards in the browser; the server renders them headless, dithers against each panel's measured colour palette, packs the frame into the panel's native byte format, and delivers it over MQTT (always-on clients) or REST (battery clients). One server drives a fleet of panels — Raspberry Pi, ESP32, Kindle, TRMNL-compatible — with 14 panels verified on real hardware.
AGPL-3.0-or-later. No cloud account, no hosted version — you run it.
browser editor Tesserae server panels
┌──────────┐ HTTP ┌──────────────────────┐ MQTT push ┌─────────────┐
│ composer │─────────▶│ headless render │────────────▶│ Pi + Inky │
│ /compose │ │ dither (measured │ ├─────────────┤
└──────────┘ │ palettes) │ REST pull │ ESP32, │
│ pack panel-native │◀───────────▶│ Kindle, │
│ schedule / rotate │ │ TRMNL │
└──────────────────────┘ └─────────────┘
What makes it interesting
- Render once, correctly. The editor preview and the production render load the same URL in headless Chromium, so a dashboard can't look right in the editor and break on the panel.
- Dumb firmware by design. Devices do no on-device image decoding — the server ships exact panel-native bytes (packed Spectra 6, 1-bit mono, 4-bit grayscale). Supporting a new panel is a board header plus one driver.
- Everything is a plugin. Widgets, themes, fonts, renderers, transports, and device kinds are drop-a-folder extension points — the seams are real directories in the repo.
- Sandboxed third-party widgets. Widgets declare the network hosts they need; the host enforces the allowlist at the socket layer. Community widgets install from an audited, sha256-pinned catalog.
- Battery-first device protocol. ESP32 clients wake,
GETtheir frame withIf-None-Match(a 304 skips the download and the slow e-ink refresh), report telemetry, and deep-sleep on a server-driven interval. - Real installation paths. Docker, Home Assistant add-on, LXC/Proxmox, shell installer — and ESP32 boards flash straight from the browser at tesserae.ink/flash, no toolchain.
Pre-1.0 and moving fast: 1,100+ tests, ruff and mypy --strict on every push, every release documented in the changelog.
Tesserae is split into focused repositories, each owning one layer:
| Layer | Repository | What it does |
|---|---|---|
| Core platform | tesserae | Server: editor, render pipeline, scheduler, plugin loader, MQTT + REST transports, docs |
| Device firmware | tesserae-device-firmware | One ESP-IDF codebase driving eight e-paper boards (Seeed reTerminal E-Series, XIAO, Waveshare, TRMNL DIY), flashable from the browser |
| Raspberry Pi clients | tesserae-device-pi-png · tesserae-device-pi-bin | Daemons that paint frames onto Pimoroni Inky panels — a PNG path for the broadest hardware support, a packed-binary path for speed |
| Microcontroller client | tesserae-device-pico-bin | RP2350 deep-sleep client for Inky panels, written in C against the Pico SDK |
| Widget catalog | tesserae-widgets | Community widgets: pinned release tarballs, sha256-verified, schema-validated, PR-reviewed |
| Home Assistant | homeassistant-tesserae-addon | Supervisor add-on — Tesserae in the HA sidebar, authenticated through HA's own session |
Native macOS menu-bar app showing live Claude Code usage: 5-hour and 7-day windows, per-model breakdowns, and extra-usage credits, with reset countdowns in the menu bar. Built because usage limits are invisible until you hit them. Swift/SwiftUI, reads OAuth tokens from the Keychain (with refresh handling), and includes a zero-dependency MQTT 3.1.1 publisher on Apple's Network framework for Home Assistant dashboards.
Self-hosted personal finance dashboard for Australian bank and brokerage accounts via the Consumer Data Right. Built because personal financial data shouldn't live in someone else's cloud. FastAPI + SQLModel/SQLite with an in-process scheduler; the async sync client is rate-limit aware and idempotent (watermarks + merge on provider ID); money is Decimal end-to-end; six tabs of ECharts visualisations with no frontend build step. mypy --strict and pytest in CI.
Custom firmware for a 256×50 vacuum-fluorescent display driven by a Raspberry Pi Pico W — eleven pages of live info (weather, now-playing with audio visualisers, 3D-print progress, Claude usage) fed over MQTT. Required a custom u8g2 fork: the GP1287BI controller isn't upstream, and the panel needs LSB-first software SPI on a non-SCK pin. OTA updates, a wireless screenshot endpoint, and Home Assistant presence/lux integration. Build writeup.
Backend — Python, Flask, FastAPI, SQLModel, SQLite, Playwright, pytest, ruff, mypy (strict)
Frontend — TypeScript, Lit, vanilla JS, Chart.js, ECharts, Astro, server-rendered HTML/CSS
Embedded — C, C++, ESP-IDF, Pico SDK, PlatformIO, ESP32-S3, RP2040/RP2350, e-paper and VFD drivers
Native — Swift, SwiftUI, Keychain, Network framework, menu-bar apps
Infrastructure — Docker, GitHub Actions, MQTT, Home Assistant, REST/OpenAPI, OAuth, systemd
- Growing Tesserae's hardware support — a generic CircuitPython client covering 400+ boards is in development
- Improving the render pipeline: palette calibration, dithering quality, panel-native formats
- Growing the community widget catalog and its review tooling
- Keeping the documentation ahead of the code
If Tesserae earns a place on your wall, sponsorship keeps the panels lit. For everything else: dmello.io · LinkedIn ·
