Guests keep their work, and micro:bit audio follows the pin your program picked
Build without an account and your circuit is waiting when you come back, plus a rounder, more faithful model of micro:bit audio wiring.
Two follow-ups from the same teacher conversation as Thursday's fixes, shipped today.
Close the tab, keep the circuit
If you build in de:volt without signing in, your circuit now saves itself locally in your browser. Come back tomorrow, or after an accidental tab close, and the editor restores where you left off, with a small note telling you it did. Nothing leaves your machine: this is browser storage, not a cloud save, so it will not follow you to another device and a cleared browser profile clears it too. For durable, shareable, versioned saves, an account is still the answer, and signing in from a guest session carries your work across. What this ends is the specific heartbreak of losing twenty minutes of wiring to a class bell and a closed Chromebook lid.
Audio wiring, round two
Last week the micro:bit went silent unless a speaker was wired, matching hardware. Today the model got two details righter. First, sound needs a complete loop rather than a merely touched pin: one speaker terminal must be reachable from the audio pin and the other from the same board's GND (or 3V for the classic two-pad headphone trick). Unplug either leg and the sound stops, exactly like pulling one alligator clip on the real thing. Second, audio follows the pin your program routes it to. MicroPython defaults to P0, and if your code selects another pin, the simulator now listens where the program actually plays. A bare board stays mute, a properly wired speaker sings, and the wiring lesson teaches itself.
Both changes came from a teacher testing against real classroom material and telling us where the model diverged. That loop works. Help → feedback reaches us directly.