InkCast

**Description**
Open-source firmware + 3D-printed enclosure for a 3.97" e-paper weather display. Built around a LILYGO T-Energy-S3 with an 18650 cell.

**Highlights**
- Large 3.97" 800x480 e-paper display
- Long battery life with a default 2-hour refresh cycle, designed for about 5-6 mAh/day and up to about 1 year on a 2000 mAh cell
- Current weather, 48-hour temperature/precipitation chart, and 6-day forecast
- Built-in web admin for Wi-Fi, coordinates, weather provider, API key, and sleep interval
- Two weather backends: OpenWeatherMap One Call 3.0 and Open-Meteo
- Browser-based WASM simulator built from the real C++ display renderer
- Graceful failure handling on e-ink: the last valid weather screen stays visible if an update fails
- 30-day sunny-days counter stored in NVS
- 3D-printed enclosure with external access to USB-C and the power switch

**Technical Notes**
- The display renderer is shared between firmware and simulator: the same C++ layout code compiles to WebAssembly via