GIOIA - Karate M5

Overview

▶ Open the TopBox M5 Json to CSV conversion App

TopBox is a reaction-time experiment that measures how quickly participants respond to visual stimuli by hitting a target. The system uses M5 IMU sensors to detect hand movements and impacts.

Hardware Setup

• LeftImu: Accelerometer on left hand
• RightImu: Accelerometer on right hand
• BobImu: Accelerometer on target (punching bag/bob)
• LeftLed: LED indicator on left side
• RightLed: LED indicator on right side

Experiment Flow

1. Idle State

• System waiting for session start
• All LEDs off
• No data collection

2. Ready State

Duration: 2 seconds (configurable via autostartDelay)

• Both LEDs show blue wave animation
• Participant prepares for trial
• Auto-advances to trial start if autostart enabled

3. Trial Start

Duration: 2000ms ± 1000ms (randomized via stimulusDelay ± stimulusDelta)

• LEDs turn off
• Variable delay creates unpredictability
• Prevents anticipation
• Trial object created and sampling begins

4. Trial Stimulus (Active Trial)

Duration: 3 seconds (configurable via trialDuration)

Visual Stimulus:

• Green LED illuminates on target side (left OR right)
• Other side remains black
• Stimulus time recorded

Detection Sequence:

1. Movement Detection (threshold: 1.25g)

   • System monitors left/right hand IMUs
   • Records leftTime when left hand accelerates above threshold
   • Records rightTime when right hand accelerates above threshold

2. Hit Detection (threshold: 1.25g)

   • After hand movement detected
   • System monitors bob/target IMU
   • Records hitTime and hitHand when impact detected
   • Rainbow animation shown on both LEDs upon successful hit

Data Sampling:

• Continuous accelerometer sampling at ~100Hz
• 500 samples per trial (~5 seconds of data)
• Records all three IMU channels throughout trial

5. Trial End

Duration: 2 seconds

• Trial marked as complete
• Timestamps converted to relative times (ms from trial start)
• Session data saved
• Rainbow animation continues

Trial Validation:

• Complete trial: has stimulus and hit times
• Incomplete trial: missing hit or moved wrong hand
• Incomplete trials are retried (moved to end of queue)

6. Session Complete

• Triggered after all trials completed
• 5-second rainbow animation on both LEDs
• Final JSON file saved with format: {totalTrials}_{playerName}_{timestamp}.json
• Session marked as completed

Session Structure

Total Trials: 48 (default, configurable)

• 24 left-side targets
• 24 right-side targets
• Randomized presentation order
• Failed trials automatically retried

Key Timing Parameters

Data Output

Each trial records:

• Trial ID and target side
• Retry count
• Timing data (start, stimulus, left/right movement, hit)
• Hit hand identification
• Complete accelerometer data arrays (500 samples × 3 channels)

Session file includes:

• Configuration parameters
• Player name and timestamp
• All trial data
• Completion status