Why your household needs a knight
Every shared kitchen has the same unsolved problem: a full bin, an open lid, and three people who each thought someone else was taking it out. The Garbage Guardian is a stick-on sensor inside the bin lid that settles it. It sleeps until motion wakes it, checks the fill level and the lid, and if things are not in order it sounds the trumpet — escalating from a polite reminder to full medieval panic — until the bin is actually empty.
🎺 No snooze button
The alarm stops when the sensor measures an empty bin or a closed lid. Not before. Knights don't snooze.
🔋 Months on two AAs
Deep sleep at a few microamps, woken only by motion. No charging cable, no dead smart gadget after a week.
📵 No app, no account
Stick it in the lid, switch it on, done. A trash bin should not have an account.
How it responds
Bin ~95% full
Alarm until emptied, escalating with the remaining space: calm at 10 cm, full panic at 1 cm. It stops when the sensor measures an empty bin — not before.
Lid open > 1 minute
Continuous alarm, extra judgmental. Close the lid and the knight forgives instantly.
Otherwise
Silence. Deep sleep. Honor. The knight only speaks when there is something worth trumpeting about.
Specifications
| Fill sensing | VL53L1X time-of-flight laser — measures distance to the trash with millimeter precision, works in total darkness |
| Lid detection | 6-axis motion sensor reads the lid angle from gravity — no magnets, no moving parts, works on any bin |
| Brain | Nordic nRF52840 (ARM Cortex-M4) |
| Alarm | Piezo trumpet with escalating patterns, from polite beep to full panic |
| Power | 2× AA batteries, months of guard duty — sleeps at a few µA, woken by motion |
| Calibration | None. Mount it, switch it on with the lid closed, done |
| Configuration | Bluetooth (thresholds, alarm personality) — planned, works fine without it |
| Mounting | Adhesive strip or magnets, tool-free, inside any bin lid |
| Size | Approx. 70 × 40 × 25 mm (final enclosure in development) |
| Firmware | Open source (MIT) — inspect every line |
| Running costs | €0. No subscription, no cloud fees — just fresh AAs a couple of times a year |
What it will never have
- Subscription — you buy it once, it guards forever
- App
- Wifi / cloud / dashboard
- Account ("a trash bin should not have an account")
- Mercy
Pre-register
The first batch of 100 units is in preparation. Pre-register and you'll get the early-bird price of €49 (instead of €59) when ordering opens. No payment now, no obligation — just first in line.
One email when ordering opens. Nothing else. Unsubscribing is honored — unlike your bin duty.