Power Profiler Skill Skill

Power Profiler Skill

Expert skill for power consumption measurement, analysis, and optimization in embedded systems. Provides integration with power analyzer tools and deep expertise in low-power design techniques.

Overview

The Power Profiler skill enables comprehensive power analysis for embedded systems, supporting:

Power analyzer tool integration (Otii Arc, Nordic PPK2, Joulescope)
Current measurement configuration and calibration
Power mode transition analysis
Battery life estimation calculations
Power profile comparison and trending
Peripheral power contribution analysis
Sleep mode leakage identification
Energy-per-operation measurements

Capabilities

1. Power Measurement Configuration

Configure and calibrate power measurement hardware:

// Example: Configure Otii Arc power analyzer
const powerConfig = {
  analyzer: 'otii-arc',
  sampleRate: 4000,        // Hz
  currentRange: 'auto',     // auto, low (uA), high (mA)
  voltageOutput: 3.3,       // Supply voltage
  triggerMode: 'gpio',      // gpio, serial, manual
  triggerPin: 'GPI1'
};

2. Power State Analysis

Analyze power consumption across different operating states:

## Power State Profile

| State | Current (avg) | Duration | Energy |
|-------|---------------|----------|--------|
| Active | 15.2 mA | 50 ms | 760 uJ |
| Processing | 45.3 mA | 10 ms | 453 uJ |
| Radio TX | 120 mA | 5 ms | 600 uJ |
| Sleep | 2.5 uA | 935 ms | 2.3 uJ |
| **Total Cycle** | - | 1000 ms | **1815.3 uJ** |

Average Current: 1.815 mA
Battery Life (1000 mAh): 551 hours (23 days)

3. Power Mode Transition Analysis

Identify and analyze power state transitions:

Wake-up latency measurement
Sleep entry timing
Transition energy overhead
Unexpected wake-up detection
Power state sequence verification

4. Peripheral Power Contribution

Break down power consumption by peripheral:

## Peripheral Power Breakdown

| Peripheral | Active Current | Sleep Current | Contribution |
|------------|----------------|---------------|--------------|
| MCU Core | 8.5 mA | 1.2 uA | 35% |
| Radio (BLE) | 6.2 mA | 0.5 uA | 25% |
| Sensors | 3.8 mA | 0.8 uA | 16% |
| Display | 4.2 mA | 0.1 uA | 17% |
| Other | 1.5 mA | 0.4 uA | 7% |

5. Battery Life Estimation

Calculate expected battery life for various usage scenarios:

// Battery life estimation parameters
const batteryEstimate = {
  batteryCapacity: 230,     // mAh (CR2032)
  dutyCycle: {
    activePeriod: 100,      // ms
    sleepPeriod: 9900,      // ms
    transmitCount: 1        // per cycle
  },
  currentProfile: {
    active: 15.0,           // mA
    sleep: 2.5,             // uA
    transmit: 120.0         // mA
  },
  derating: 0.85            // 85% capacity utilization
};

// Calculated: 2.3 years battery life

Process Integration

This skill integrates with the following processes:

| Process | Integration Point | |---------|-------------------| | power-consumption-profiling.js | Primary execution - all phases | | low-power-design.js | Measurement and validation phases | | real-time-performance-validation.js | Power budget verification |

Tool Integration

Supported Power Analyzers

| Tool | Features | Connection | |------|----------|------------| | Otii Arc | High precision, automation API | USB, REST API | | Nordic PPK2 | Source/ampere meter modes | USB, nRF Connect | | Joulescope | Real-time streaming, triggers | USB, Python API | | Keysight N6705C | Multi-channel, high accuracy | GPIB, USB, LAN | | Qoitech Otii | Cloud integration, sharing | USB, Otii Desktop |

Data Export Formats

CSV time-series data
JSON power profiles
PNG/SVG visualizations
Interactive HTML reports
Otii project files (.otii)
Joulescope capture files (.jls)

Workflow

1. Setup Measurement Environment

# Verify power analyzer connection
otii-cli device list

# Configure measurement parameters
otii-cli project create \
  --name "power-profile-$(date +%Y%m%d)" \
  --voltage 3.3 \
  --current-range auto

2. Capture Power Profile

# Start recording with GPIO trigger
otii-cli recording start \
  --trigger gpio:GPI1:rising \
  --duration 10s

# Or use serial trigger
otii-cli recording start \
  --trigger serial:START \
  --stop-trigger serial:STOP

3. Analyze Results

# Export measurement data
otii-cli recording export \
  --format csv \
  --output power-data.csv

# Generate statistics
otii-cli statistics \
  --markers state:active,state:sleep \
  --output stats.json

4. Generate Report

The skill generates comprehensive power analysis reports including:

Executive summary with key metrics
State-by-state power breakdown
Transition timing analysis
Battery life projections
Optimization recommendations
Comparison with targets/baselines

Output Schema

{
  "summary": {
    "averageCurrent_mA": 1.815,
    "peakCurrent_mA": 120.0,
    "sleepCurrent_uA": 2.5,
    "estimatedBatteryLife_hours": 551
  },
  "powerStates": [
    {
      "name": "active",
      "current_mA": 15.2,
      "duration_ms": 50,
      "energy_uJ": 760
    }
  ],
  "transitions": [
    {
      "from": "sleep",
      "to": "active",
      "latency_us": 125,
      "energy_uJ": 1.2
    }
  ],
  "peripheralBreakdown": {
    "mcu": { "active_mA": 8.5, "sleep_uA": 1.2 },
    "radio": { "active_mA": 6.2, "sleep_uA": 0.5 }
  },
  "recommendations": [
    "Reduce radio TX power by 3dB to save 15% energy",
    "Enable peripheral clock gating during sleep"
  ],
  "artifacts": [
    "power-profile.csv",
    "power-report.html",
    "waveform.png"
  ]
}

Best Practices

Measurement Setup

Use kelvin sense connections for accurate voltage measurement
Minimize wire length between analyzer and DUT
Ensure stable power supply to analyzer
Allow thermal stabilization before measurement

Calibration

Zero-offset calibration before each session
Verify measurement accuracy with known load
Document measurement uncertainty

Analysis

Use markers to identify power states
Compare against power budget requirements
Track power metrics across firmware versions
Document measurement conditions

References

Nordic PPK2 User Guide
Joulescope User Guide
Otii Arc Documentation
"Power Management for Internet of Things" - ARM
Low-Power Design Methodology Manual

MCP Server Integration

Compatible MCP servers for enhanced functionality:

| Server | Purpose | |--------|---------| | embedded-debugger-mcp | Coordinate debug probes with power measurement | | serial-mcp-server | Serial trigger synchronization | | tinymcp | Device state monitoring |

Agent Skills: Power Profiler Skill

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