0.4
31 July 2026 latestThe largest release since the project began. The cube learned to measure the air, gained a second way to be installed — one that does not erase your settings — and had its public claims taken apart and rewritten to match what the firmware actually does.
- newAir sensors, optional, on Port A. M5Stack CO2L, CO2 and ENV Pro — singly or both through a passive hub. Carbon dioxide, temperature, humidity, pressure and a gas-resistance trend. The cube describes the air, never the person, and it is not a carbon-monoxide or smoke detector. It writes nothing to the sensors' own memory.
- newHome screens follow the hardware. Without a module, one home: the radio. With a module, two more — a minimal one and one carrying the air. A home you may select but may not keep is not a home, which is why the one logic change in this release is the configuration validator.
- newTwo ways to install instead of one. A factory image written from zero that erases every setting, and an application-only update that keeps them: remembered Wi-Fi, the paired speaker, chosen stations, volume, home screen. Separate files, separate buttons, and each name says which one it is before you click.
- newThe catalogue grew to 222 stations, and two of them have a story. Four arrived: Radio Nowy Świat, Radio Silesia and Radio Kraków — all three admitted on their own measurements — and finally Radio 357. Both listener-funded, both in the shipped 222.
- fixedRadio 357 nearly left the catalogue — on a cause that had been attributed wrongly. One evening we read audio dropouts as a problem with that station. The next day's log said otherwise: the buffer starved on a different station too, and the same image that starved at midnight ran with a full buffer in the morning. The culprit was the tax for running Wi-Fi and Bluetooth at once, not a catalogue entry. Rather than remove a working station, we aimed an hour-long test at it over Bluetooth and the question was settled by measurement, on the image that shipped.
- newThe sources ship beside the binary and now rebuild without git. As with 0.2.1 — except that the rebuild instruction used to stop on its first line, because the build called a git command in a tree that has no git by policy. That is the first thing anybody exercising the GPL runs into.
- what is not thereAlerts are silent. Seventeen rules with sourced thresholds work and put a sentence on the screen, but the strongest level computes a sound flag that nothing in this release reads. No alert ever makes a noise.
- what is not thereNo over-the-air updates, by design. Every update needs a cable. There is no telemetry, no account and no remote catalogue.
- what we did not testNobody ran the update path on a physical cube — neither the update itself nor an upgrade from a configured 0.2.1. There is also no uninterrupted hour: the session ran 69 minutes but contained deliberate reboots, which produced evidence that the cube recovers instead. The 0.4 evidence comes from one cube; 0.2.1 remains the only release checked on three hardware revisions.
factory image 2.5 MB
update 2.4 MB
GPL-3.0-or-later
download factory image ↓
update withdrawn for now
installation guide →
Factory SHA-256:
3040146fc08fd07ccad78a9992cb4d5053bd573f0dc6cd8eebc7bffe48d2467a
Update SHA-256: e8642c56364b37169620384ca92d635e97b374d2aa7c06baba0f7d3785ffee50
