Sprinter Van HUD

Green arrows mean power is actively flowing that way right now. "House battery" shows a stand-in number (borrowed from the solar controller, since they're the same physical battery) until its own direct Bluetooth link is confirmed working. "Starter battery" shows "--" until its sensor is wired in. Panel voltage isn't available yet either — that's a different reading than the ones currently being decoded.

Green = net charging (solar winning), red = net discharging (something's using more than the sun's providing) — colored by the sign of the value, not by whether the line is momentarily wiggling up or down, so it doesn't flicker on every small fluctuation. Real telemetry arrives every 30s; ranges shorter than that will just show very few points, which is correct, not broken. Ranges over 24h use daily averages (min/max within a day aren't kept, just the average), not the raw 30s data.

These are read independently, from different points in the system (MPPT input terminals vs. the battery shunt vs. the battery's own internal BMS) — small voltage/current disagreements between cards are expected and fine, not a bug.

Estimated from the cellular hotspot's IP address (Cloudflare edge geolocation), not real GPS — this is city/region-accurate at best and can be off by miles depending on carrier network layout. No GPS module is installed on the van yet.

Sun timing and position are exact astronomy, not a guess. Cloud cover, temperature, and "best window" are forecast data (Open-Meteo) — a real prediction, not a measurement, so treat it as a heads-up rather than gospel. Inside estimate is a rule of thumb (outside high + 10°F) based on this van's insulation, which has kept it from tracking any hotter than that on past hot days — not a live sensor reading.

Sense-only for now — closed-to-ground reads as locked. Not a control, just a status read.

This is the ESP32-S3's own die temperature, not an outside/cabin sensor — it reads a bit warm because it sits close to the MCU itself and the display backlight.

Currently unassigned pins, held for future use — either triggering a relay (interior lights, a water pump, a door lock solenoid, the inverter's on/off line) or reading a digital/analog sensor (a tank-level float switch, a temperature probe, a door/motion sensor). Toggling one here just flips that physical pin now, ahead of anything real being wired to it. Everyone can see this page — changing a pin's state asks for a password first, and a wrong guess just does nothing.

Manual-only, no auto-polling — this button is the only trigger, and it can take up to a few minutes to reach the van.