> Documentation index: https://docs.squeekchain.com/llms.txt. Use it to find every page.

# The WHEELY9000

> The WHEELY9000 is the hamster mining device that records wheel activity as work, with independent video.

Web version: https://docs.squeekchain.com/system/installation/

## TL;DR

- The WHEELY9000 is the hamster mining device: it records accepted wheel-magnet passages as work.
- A sensor detects the magnet, and a small computer applies the counting rules and saves accepted work in ten-minute rounds.
- Independent cameras provide video on a separate path from measurement.

## What is the device?

The WHEELY9000 is the hamster mining device, built around a wheel, a wheel-mounted magnet, and a sensor. When the magnet passes the sensor, the device checks the reading and saves an accepted passage as one work unit. Its saved work is what settles on Ethereum and completes Squeek blocks.

A Raspberry Pi Pico carries the sensor readings to a Raspberry Pi, which applies the counting rules and saves the results. Independent cameras let you watch the device; the sensor record is what counts work.

## How it works

The wheel-mounted magnet produces active and inactive readings from the Hall sensor. The Pico passes those observations to the Pi, which checks them and saves accepted passages in ten-minute rounds. The production signing chip signs saved measurement records for delivery to the Oracle.

Measurement and video run independently. Counting and round closure continue through a camera outage, and the measurement record shows any fault in counting regardless of what the video shows.

## Technical detail: hardware responsibilities

| Part | Function | Boundary |
|---|---|---|
| Wheel and magnet | Trigger active/inactive sensor readings | Do not identify what moved the wheel or in which direction |
| Hall sensor and Pico | Send readings with their order and timing | Do not count accepted work, close rounds, or sign records |
| Pi measurement service | Check counting rules and save passages and completed rounds | Cannot replace uncertain measurements with guesses |
| Durable SQLite state | Save work, round history, and records awaiting delivery | Must be preserved, unlike a replaceable display cache |
| Production signing chip | Sign records with a key that cannot be exported | Cannot verify the data supplied by its host |
| Cameras | Supply independent video feeds | Cannot access the measurement database or authorize settlement |

Three cameras, two Raspberry Pi camera modules and one USB camera, run as separate services. Public playback reveals viewing information, not camera controls or publishing credentials.

### Rules and boundaries

- One accepted passage is one work unit. It does not prove that an animal completed a wheel revolution.
- At startup, the Pi must observe an inactive sensor before counting a new passage.
- Camera or playback failure alone does not stop counting, round closure, or measurement delivery.
- Captured audio must not leave the device. If a provider requires silent audio, it is not microphone audio.
- The WHEELY9000 does not hold settlement signer or relayer keys.
- Software updates must preserve saved measurement history; an update does not justify resetting the counter.
- Video cannot fill gaps in the sensor record.

### Separate reporting histories

The Pi keeps a physical counter and separate reporting histories. Each reporting history has its own installation identity, counter epoch, start time, and delivery state, so its total isn't the physical counter's lifetime total. Comparisons need to use the matching reporting history.

## Related pages

- [Measuring wheel activity](https://docs.squeekchain.com/system/measurement.md)
- [Components and responsibilities](https://docs.squeekchain.com/system/components.md)
- [Privacy](https://docs.squeekchain.com/security/privacy.md)
- [What the system proves](https://docs.squeekchain.com/security/proof-limits.md)