# ZT3 Wheelie

> ZT3 Wheelie is a proprietary Android app (Android 8.0 and later) for a wheelie assist on the Segway-Ninebot ZT3 Pro D. An ESP32 with an MPU6050 motion sensor reads the scooter's tilt 1000 times per second; the app connects to it over Bluetooth LE with a six digit PIN and an encrypted link and shows the attitude as a 3D model, the wheelie angle against an adjustable limit, g-forces and a ten second history. It updates itself from this page. Use on private ground only.

Everything below is also available without JavaScript: the page's HTML carries the current version and checksums, and `/` returns Markdown for `Accept: text/markdown`.

## Get the app

- [Newest release](https://zt3-pro-wheelie-control.celox.io/download): the file for your platform — 302 to the newest file, a verified copy served from this site (resumable)
- [APK](https://zt3-pro-wheelie-control.celox.io/download/android): Android 8.0+
- [Newest release as JSON](https://zt3-pro-wheelie-control.celox.io/latest.json): `version`, `published`, `notes`, and `assets[]` with `target`, `name`, `url`, `size` (bytes), `sha256`; refreshed every 15 minutes
- [All releases and notes](https://github.com/pepperonas/zt3-pro-wheelie-control-releases/releases)

## Docs

- [Product page as Markdown](https://zt3-pro-wheelie-control.celox.io/index.md): features, install steps, verification, FAQ, with the current version and checksums filled in
- [Agent skill: get ZT3 Wheelie](https://zt3-pro-wheelie-control.celox.io/skills/get-zt3-pro-wheelie-control/SKILL.md): download, verify and install, step by step
- [Changelog](https://zt3-pro-wheelie-control.celox.io/changelog.md): Markdown, mirrored from GitHub every 15 minutes
- [README](https://github.com/pepperonas/zt3-pro-wheelie-control-releases#readme)

## Install

1. One file for every phone with Android 8.0 or later.
2. Open the file. Android asks once whether your browser may install apps, allow it.
3. Open Devices, search, tap ZT3-Wheelie-XXXX and enter the PIN. Read it once over USB with the command `pin`.

## Verify

- SHA-256 of every file: `assets[].sha256` in [latest.json](https://zt3-pro-wheelie-control.celox.io/latest.json)
- Signing certificate SHA-256: `0e672ef6dc012b6d1824609489db9ce155aecf32a6d881b379b7cb30fe394dde`

## Features

- Attitude in 3D: A model of the sensor board turns with the scooter. Accelerometer and gyro are fused with a Mahony filter, so the angle stays calm while you ride.
- Wheelie angle and limit: Set the zero point with both wheels down, pick the axis the scooter tilts around and set your limit. The side view turns amber near it and red above it.
- G-forces: Total acceleration, the part without gravity, the peak and an X/Y plot with a one second trail show accelerating, braking and bumps.
- Encrypted Bluetooth: Each controller makes its own six digit PIN and shows it only over USB. Without it no phone can pair, read data or send commands.
- Honest data: Only complete lines inside the sensor's range are used. Corrupted lines are counted and dropped, never shown as values.
- Updates itself: The app checks this page, downloads a new version, verifies its SHA-256 and hands it to Android's installer.

## Scope and limits

- Android only; not on Google Play, distributed as an APK from this page.
- Needs the ZT3 Wheelie controller (ESP32 with MPU6050) running the matching firmware.
- The app shows and configures; it does not limit the throttle yet. That is a later phase of the project.
- Connected only while the app is open; there is no background service.
- Yaw comes from the gyro only and drifts slowly.
- The data stream has 50 lines per second; short impacts between two lines are not shown.

## Optional

- [Source code](https://github.com/pepperonas/zt3-pro-wheelie-control-releases)
- [Licence (Proprietary)](https://github.com/pepperonas/zt3-pro-wheelie-control-releases/blob/main/LICENSE)
- [Agent resource catalog](https://zt3-pro-wheelie-control.celox.io/.well-known/ai-catalog.json)
- [Author: Martin Pfeffer, celox.io](https://celox.io)