Viewing Sensor Data¶

Learn how to access, interpret, and analyze sensor readings across the GreenCop platform.

Data Access Points¶

1. Dashboard (Overview)¶

Best For: Quick glance at entire system

Shows: - Average temperature across all sensors - Total active sensors - Bar chart of all current readings - Historical trend (30-day line chart) - Recent alerts

Refresh: Automatic on page load

Navigate: Home icon in sidebar or logo click

2. Sensors Page (Current State)¶

Best For: Current readings for all sensors

Shows: - Grid of all sensors - Latest temperature per sensor - Latest humidity per sensor - Last update timestamp - Room assignments

Refresh: Auto-polls every 10 seconds

Navigate: Sensors icon in sidebar

3. Sensor Detail Page (Deep Dive)¶

Best For: Detailed analysis of single sensor

Shows: - Large current temperature and humidity - Selectable time ranges (1h, 24h, 7d) - Temperature history line chart - Humidity history line chart - Sensor metadata

Refresh: Manual or via time range selector

Navigate: Click any sensor card

Reading the Data¶

Temperature Display¶

Format: 25.3°C - Number: Actual temperature - Unit: Degrees Celsius - Precision: 0.1°C (one decimal place)

Color Coding: - Orange background: Temperature data - Red: Alert condition (> threshold)

Typical Ranges: - 18-27°C: Ideal for servers - 28-35°C: Warm, monitor closely - >35°C: Concerning, investigate

Humidity Display¶

Format: 45.2% - Number: Relative humidity - Unit: Percentage - Precision: 0.1%

Color Coding: - Blue background: Humidity data - Dark blue: Alert condition (> threshold)

Typical Ranges: - 40-60%: Ideal for servers - 30-70%: Acceptable - <30% or >70%: Investigate

Timestamps¶

Format: 1/15/2025, 10:30:45 AM - Date: Month/Day/Year - Time: Hour:Minute:Second AM/PM - Timezone: Browser local time (data stored as UTC)

Freshness Indicators: - <1 min: Very fresh, green - 1-5 min: Recent, normal - 5-30 min: Aging, yellow - >30 min: Stale, red (likely offline)

Charts and Graphs¶

Bar Chart (Dashboard)¶

Purpose: Compare multiple sensors at once

Axes: - X-axis: Sensor names - Y-axis: Temperature (°C) or Humidity (%)

Bars: - Orange: Temperature - Blue: Humidity - Side-by-side for comparison

Interaction: - Hover: See exact values - No zoom/pan (fixed view)

Line Chart (Trends)¶

Purpose: Visualize changes over time

Axes: - X-axis: Time (formatted as HH:MM) - Y-axis: Temperature (°C) or Humidity (%)

Lines: - Orange: Temperature trend - Blue: Humidity trend - Smooth curves

Interaction: - Hover: See point values - Legend: Click to hide/show series

Time Ranges¶

Available Options¶

1 Hour: - Last 60 minutes of data - Most detailed view - ~60-120 data points - Best for: Real-time troubleshooting

24 Hours: - Last day of data - Shows daily patterns - ~288-480 data points - Best for: Daily cycle analysis

7 Days: - Last week of data - Weekly trends - ~1000-2000 data points (sampled) - Best for: Long-term patterns

Selecting Time Range¶

Navigate to sensor detail page
Click one of three buttons: "1 Hour", "24 Hours", "7 Days"
Chart updates automatically
Selection highlighted in blue

Data Freshness¶

Live Polling¶

Sensors Page: Auto-refreshes every 10 seconds Dashboard: Fetches on page load, manual refresh needed Sensor Detail: Fetches on load and time range change

Manual Refresh¶

Reload browser page (F5 or Cmd+R)
Navigate away and back
Change time range (sensor detail page)

Interpreting Patterns¶

Normal Patterns¶

Daily Temperature Cycle: - Rises during business hours (people, equipment active) - Drops at night (less activity) - 3-5°C variation typical - Smooth wave pattern

Stable Humidity: - Relatively flat line - Minor variations (<5%) - No sudden spikes

Abnormal Patterns¶

Sudden Spike: - Sharp upward jump - Indicates: Equipment failure, cooling loss, heat source - Action: Immediate investigation

Gradual Rise: - Slow increase over hours/days - Indicates: Cooling capacity issue, increasing load - Action: Plan maintenance

Erratic/Noisy: - Wild fluctuations - Indicates: Sensor malfunction, poor placement - Action: Check sensor hardware

Flat Line: - No variation over time - Indicates: Sensor stuck, not updating - Action: Check sensor connectivity

Empty States¶

No Data Available¶

Display: "No data available" in gray text

Causes: - Sensor just registered (wait 30 seconds) - Sensor offline (check hardware) - BigQuery issue (check backend logs) - Sensor ID mismatch

Solutions: - Wait for first reading - Verify sensor is publishing - Check sensor ID matches registration

No Historical Data¶

Display: "No historical data available" in chart area

Causes: - New sensor with <1 hour of data - BigQuery ingestion issue - Time range has no data points

Solutions: - Wait for more data to accumulate - Select different time range - Check BigQuery table has rows

Data Accuracy¶

Sources of Error¶

Sensor Calibration: ESP32/DHT sensors have ±0.5°C accuracy
Placement: Poor location (sunlight, heat sources) skews readings
Network Delays: 1-5 second lag from sensor to dashboard
Sampling: Charts may show sampled data, not every point

Ensuring Accuracy¶

Calibrate sensors before deployment
Place in representative locations
Avoid direct airflow over sensor
Cross-reference multiple sensors
Compare with calibrated thermometer

Exporting Data¶

Future Feature

CSV/Excel export coming soon

Current Options: - API: Query historical data endpoint - BigQuery: Direct SQL queries - Screenshots: Browser screenshot tools

API Example:

GET /api/v1/data/historical/sensor-001?start_time=2025-01-01T00:00:00Z&end_time=2025-01-15T23:59:59Z