🎮 Gamepad — Trigger Pressure Test

1. Connect your controller (USB recommended for the most consistent results).
2. Press Detect Controller and press any button on the controller to wake it.
3. Click Start and squeeze the triggers — the live meters will update.
4. If you have a small consistent offset at rest, use Calibrate Neutral to set the baseline.
5. Adjust Deadzone to ignore tiny unwanted signals near rest, and use Sensitivity to scale values for easier reading.
6. When finished, export the CSV for logging or deeper analysis.

The browser's Gamepad API exposes controller inputs as either axes or analog button values (0.0 to 1.0). Different controllers map triggers differently — some expose triggers as axes (usually axes[2] / axes[5] or similar), while others expose them as analog buttons with a value between 0 and 1. This tool samples those values at the configured interval, applies calibration offsets and deadzone thresholds, scales by sensitivity, and renders meters + numeric readouts in real time.

Typical mappings

• Xbox-style: triggers often appear as separate analog buttons (buttons[6], buttons[7]) with a .value property.
• PS-style: triggers sometimes appear as axes or as buttons — behavior varies across browsers and OS.
• Generic USB: mapping is inconsistent — that’s why this tool tries multiple detection strategies.

1) Prepare

Use a stable surface or hold the controller naturally. If testing wireless controllers, ensure they are fully charged to eliminate battery-related weakness.

2) Detect

Click Detect Controller. Press any button if the page shows none. Confirm that the controller name appears.

3) Baseline & Calibration

With your hands off the triggers, click Calibrate Neutral. The tool will record current resting values and subtract them from subsequent readings so small offsets are accounted for.

4) Sampling & Live Check

Press Start and squeeze each trigger gradually from 0% to 100% and back. Observe the meters for smoothness, linearity, and symmetry between left/right triggers.

5) Deadzone & Sensitivity

Set a small deadzone (e.g., 0.01–0.03) to ignore tiny idle noise. Use sensitivity to scale the displayed values if you prefer a larger numeric range for fine control checks.

6) Export & Analyze

Use Export CSV to save time-stamped trigger samples for plotting in a spreadsheet or Python. Look for jitter, offset, hysteresis (different values when increasing vs decreasing pressure), and non-linear regions.

Healthy Trigger

• Smooth, monotonic increase from 0.00 to ~1.00 as pressure increases.
• Consistent behavior when slowly releasing the trigger — values should decrease along the same curve (minimal hysteresis).
• Minimal jitter at rest (within deadzone).

Warning Signs

• Offset at rest: Trigger reads above zero when untouched — calibration or hardware cleaning may help.
• Jitter: Rapid small fluctuations around a value — may indicate electrical noise or worn sensor.
• Dead zones inside range: Not responsive until trigger is pressed a long way — possible mechanical wear or driver scaling.
• Hysteresis: Value while releasing is different than when pressing — may signal worn potentiometers or sensor lag.

Analog Buttons

Buttons with an analog value are accessed as gamepad.buttons[i].value. This tool checks likely button indices (6,7) used by many controllers.

Axes

Some controllers present triggers as axes (range -1..1 or 0..1). The script normalizes different ranges and tries common axis slots (2,3,4,5) to find triggers.

Fallback Strategy

If typical mappings fail, the tool heuristically picks the clearest analog signal that changes when you squeeze triggers — this catches many odd mappings.

General

1. Use a wired USB connection to reduce latency and power issues.
2. Try different browsers — Chrome/Edge are often the most consistent for Gamepad API behavior.
3. Ensure your system drivers are up-to-date (especially for Xbox/official controllers).

Windows

• Xbox controllers usually work reliably via USB/Bluetooth. Use Edge/Chrome for best Gamepad API support.
• If analog triggers show as digital buttons, check controller firmware or vendor software (e.g., Xbox Accessories).

macOS

• macOS mapping is sometimes inconsistent. Consider wired connection and test in Chromium-based browsers.
• Third-party mapping utilities may change how triggers are exposed; disable them while testing to get raw values.

Android

• Chrome on Android typically supports gamepad axes; use USB OTG for reliable power and mapping when available.

Linux

• Kernel drivers and udev rules affect mapping. Use tools like jstest-gtk or SDL test apps to verify outside the browser.

Quick Safe Steps

• Power off and remove batteries/USB before opening (if you open it).
• Blow compressed air around the trigger housing to remove dust.
• Wipe surrounding surfaces with a dry cloth — don’t spray liquids directly into openings.

Contact Cleaner (Advanced, risky)

Some analog trigger issues improve with a tiny amount of electronics contact cleaner applied to the potentiometer or hall sensor area, followed by working the trigger. This is risky (may remove grease or damage plastic) and voids warranties — proceed only if comfortable and out of warranty.

Replacing Trigger Modules

For many controllers, trigger modules are replaceable but require micro-soldering. If you’re not experienced with electronics repair, professional service is recommended.

Design Recommendations

• Map triggers to analog actions (throttle, brake, aim-down-sights) when available — they provide finer control than digital buttons.
• Implement configurable deadzones and sensitivity scaling in options (players and controllers vary widely).
• Detect and fallback gracefully when triggers are digital (treat as binary pressed/unpressed).

Use Export CSV to save logs of time-stamped raw and processed trigger values. Typical analysis includes:

• Max/Min detection — ensures full travel reaches near 1.0 and 0.0.
• Hysteresis check — compare increasing vs decreasing values.
• Jitter and noise — standard deviation when held at a target value.

CSV Format

The exported CSV contains columns: timestamp, left_raw, right_raw, left_processed, right_processed.

Why This Matters

Not every user can operate analog triggers easily — include alternative mappings (keyboard, buttons) and allow triggers to be remapped to discrete actions or toggles where appropriate.

Keyboard Simulation

This tool includes a keyboard simulation mode (checkbox) — use Q/E for left trigger and U/O for right trigger to simulate analog values in steps for testing without a physical controller.

Q: My triggers show values even when untouched — is that broken?

A: Small non-zero resting values are common due to sensor tolerances. Use calibration to set the current resting point to zero. If the offset grows over time or is large (>0.1), consider cleaning or hardware checks.

Q: Trigger feels unresponsive near the middle — what is that?

A: That suggests a dead zone, mechanical slop, or driver scaling. You can configure in-game deadzone settings to compensate, but hardware repair may be necessary for large dead zones.

Q: Why do triggers map differently across devices?

A: Standards vary — manufacturers and OS drivers decide mappings. This tool attempts to detect common patterns but cannot guarantee every device mapping.

Q: Will calibration fix trigger drift?

A: Calibration can compensate for a steady offset but not for erratic drift or mechanical wear. If values change rapidly, cleaning or replacement is needed.

Before Surgery (Quick Checks)

• Try wired connection first.
• Test controller on another device to isolate hardware vs environment.
• Update controller firmware and OS drivers whenever possible.

Developer & QA Checklist

1. Include deadzone & sensitivity options in settings.
2. Log trigger samples during playtests for objective feedback.
3. Provide remapping for accessibility and users with limited dexterity.

When to Replace

If the trigger requires a deadzone larger than ~0.20 to be usable, or if hysteresis and jitter significantly affect gameplay, replacement or professional repair is usually more practical than long-term software workarounds.