Vibration Counter

A single-file mobile web tool that uses your device's motion sensors to detect and count vibrations / taps / impacts in real time — built for repetitive physical tallying (e.g. counting bacterial colonies by tapping) on an iPhone or Apple Watch, straight from the browser, no install.

Languages: English | 中文

🔗 Open the live demo → — open it on your phone over HTTPS, grant motion access, and tap the big number.

Highlights

• 📲 Runs in the phone browser — no install, one index.html.
• 🎯 High-pass filter cancels gravity/orientation, so only real shakes count.
• 🎚️ Tune sensitivity, upper-limit, and cooldown to match your tapping.
• ⏯️ Tap to reset, long-press to pause; live peak / rate / timer.
• 🔒 Stays awake on iPhone & Apple Watch via multiple anti-lock tricks.

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What it does

You open the page on your phone (or Apple Watch), grant motion-sensor access, and tap the big number to start. Every physical vibration that lands inside your configured intensity band increments the count. A high-pass filter continuously absorbs gravity and orientation into a slow baseline, so only the deviation from that baseline — the actual shake — is measured. You tune three knobs (sensitivity, action upper-limit, cooldown) so it counts the taps you care about and ignores both background jitter and oversized bumps.

It is a hands-free physical-event tally, not a scientific accelerometer logger — every figure is a heuristic read from the consumer motion API, not a calibrated measurement.

How to use

1. Serve over HTTPS. Motion sensors are only available in a secure context; open the page via https:// (e.g. GitHub Pages), not a raw file://.
2. Grant permission. On iOS 13+ a button appears — tap 授权传感器 / Grant sensor access and accept the system prompt.
3. Tap the big number to start. The status dot turns active and detection begins.
4. Tap the number again to reset it to zero (and force-resubscribe the sensor stream); long-press (~0.6 s) to pause/resume without losing the count.
5. Read the live panel: the accelerometer bar shows current intensity with your lower/upper markers; the three stat cells show peak (m/s²), rate (counts/min), and elapsed time.
6. Quick-convert: tap any of the ×2 / ×4 / ×8 / ×63.6 buttons to snapshot count × factor onto the button; tap again to restore the factor label.

Controls & display

Element	Action / Meaning
Big number	Tap = reset to 0 · Long-press = pause/resume · also the start trigger
Accelerometer bar	Live vibration intensity (0–30 m/s²) with lower-limit & upper-limit markers
Peak / Rate / Time	Session peak intensity, counts-per-minute, and elapsed timer
×2 ×4 ×8 ×63.6	Toggle a count × factor snapshot on the button (factors are user-defined, no fixed physical meaning)

Settings (灵敏度设置)

Setting	Range	What it does
Sensitivity	1–10	Maps to a lower threshold (1 ≈ 20 m/s², needs a big motion → 10 ≈ 2 m/s², a light shake triggers).
Action upper-limit	20–45	Vibrations stronger than this are treated as oversized impacts and not counted; slide to the top (45) for unlimited.
Cooldown	100–1000 ms	Minimum gap between two counts; continuous shaking is tallied at this cadence.
Current band	(display)	Shows the active lower – upper interval; only vibrations inside it are counted.

How it works under the hood

• High-pass filtering — an exponential moving-average baseline (α = 0.05) tracks gravity/orientation; the count uses |magnitude − baseline|, so tilting the device doesn't false-trigger.
• Touch guard — counting is suppressed for ~400 ms after any screen touch, so tapping to reset/pause never registers as a vibration.
• Stay-awake, belt-and-suspenders — Screen Wake Lock API + a near-silent 1 Hz AudioContext oscillator + a MediaSession "playing" flag + NoSleep.js, each wrapped in try/catch so any unsupported one is silently skipped. This fights iOS/watchOS auto-lock.
• Stall watchdog — iOS silently kills the devicemotion stream when backgrounded or idle. A 1 s heartbeat, plus visibilitychange / pageshow / touch hooks, auto-resubscribes the stream when it goes quiet for >3 s, so the counter "wakes up" by itself.
• rAF-batched UI — at 60 Hz+ the detection logic runs in the event callback for accuracy, while purely visual updates are coalesced into one requestAnimationFrame per frame to keep taps responsive.

Requirements & compatibility

• HTTPS / secure context is mandatory for sensor access.
• iPhone (iOS Safari) — fully supported, including the iOS 13+ permission prompt and Wake Lock.
• Apple Watch (watchOS WebKit) — targeted; some keep-awake paths (Wake Lock, NoSleep) may not take effect, but counting still works if motion events arrive.
• Android Chrome — the standard devicemotion path works; some keep-awake tricks vary by vendor.
• No build step, no dependencies to install — a single index.html (NoSleep.js loads from a CDN; if it fails, counting is unaffected).

Limitations

• Heuristic, not calibrated. Values come from the consumer motion API; they are not a metrology-grade measurement and vary by device.
• Threshold-based tallying. A vibration is counted only if it lands in the [lower, upper] band and clears the cooldown — overlapping or sub-threshold events can be missed, and the cooldown caps the maximum count rate.
• Platform keep-awake is best-effort. Auto-lock prevention is not guaranteed, especially on watchOS; the screen may still sleep.
• Sensor stream is fragile on iOS. Despite the watchdog, aggressive backgrounding can still interrupt the stream until you return to the page.
• No persistence. Count, settings, and stats are in-memory only; a reload starts from zero.

Roadmap / Outlook

• Persist settings & sessions (localStorage) so sensitivity/cooldown and the last count survive a reload.
• Configurable quick-convert factors instead of the fixed ×2/×4/×8/×63.6.
• Export / history — log per-session counts, rate curves, and peaks for later review.
• Calibration helper — a guided routine to pick a sensitivity/threshold for a given tapping style.
• Installable PWA — offline manifest + service worker so it launches like a native app.

License & usage

Copyright © 2026 hello-claude. All rights reserved.

This project is owned and maintained solely by its author. Modifying it without the author's explicit, prior authorization is not permitted. Any unauthorized or modified copy is unofficial, unsupported, and used entirely at your own risk; the author accepts no liability for any such copy. (This mirrors the authorization notice embedded at the top of index.html.)