Grafana Dashboard

Grafana is our visualization layer, displaying real-time car telemetry from TimescaleDB.

Installation (macOS)

brew install grafana
brew services start grafana

Access at: http://localhost:3000 Default login: admin / admin

Remote Access Configuration

To access Grafana from other machines (via local network IP):

Edit /opt/homebrew/etc/grafana/grafana.ini:

[server]
http_addr = 0.0.0.0
http_port = 3000

Restart: brew services restart grafana

Data Source Setup

1. Go to Connections → Data Sources → Add data source
2. Select PostgreSQL
3. Configure:

4. Click Save & Test → Should show "Database OK"

Dashboard Panels

Gauge Panels (Current Values)

All gauges use this query pattern:

SELECT time, <column> as "<Label>"
FROM car_metrics
ORDER BY time DESC
LIMIT 1

Finding Units

1. In panel editor, scroll to Standard options
2. Click Unit dropdown
3. Search for unit name:
   • celsius → Temperature
   • percent → Misc → Percent (0-100)
   • kPa → Pressure → Kilopascal
   • velocitykmh → Velocity → km/h
   • volt → Electrical → Volt

Time Series Panel (History)

SELECT time, rpm, speed, coolant
FROM car_metrics
WHERE time > NOW() - INTERVAL '1 hour'
ORDER BY time

• Type: Time series
• Title: Telemetry History

Dashboard Layout

┌─────────┬─────────┬─────────┬─────────┬─────────┐
│   RPM   │  Speed  │Throttle │  Load   │ Battery │
│  Gauge  │  Gauge  │  Gauge  │  Gauge  │  Gauge  │
├─────────┼─────────┼─────────┼─────────┼─────────┤
│ Coolant │ Intake  │   MAP   │  Fuel   │ Timing  │
│  Gauge  │  Gauge  │  Gauge  │  Gauge  │  Gauge  │
├─────────┴─────────┴─────────┴─────────┴─────────┤
│              Time Series Graph                  │
│         (RPM, Speed, Coolant over time)         │
└─────────────────────────────────────────────────┘

Refresh Rate

For real-time monitoring:

1. Click the refresh icon (top right)
2. Set to 5s or 10s auto-refresh
3. Set time range to "Last 5 minutes" or "Last 15 minutes"

Threshold Colors (Gauges)

To add color thresholds:

1. Edit panel → scroll to Thresholds
2. Add threshold values:

Example for RPM:

• Base (green): 0
• Yellow: 5000
• Red: 6500

Example for Coolant:

• Base (blue): 0
• Green: 80
• Yellow: 100
• Red: 110

Useful Queries for Analytics

Max Speed During Trip

SELECT MAX(speed) as "Max Speed"
FROM car_metrics
WHERE time > NOW() - INTERVAL '2 hours'

Average Fuel Consumption Estimate

SELECT
  AVG(engine_load) as avg_load,
  AVG(rpm) as avg_rpm,
  AVG(throttle) as avg_throttle
FROM car_metrics
WHERE time > NOW() - INTERVAL '1 hour'

Time at High RPM

SELECT
  COUNT(*) as high_rpm_seconds
FROM car_metrics
WHERE time > NOW() - INTERVAL '1 hour'
  AND rpm > 4000

Exporting Dashboard

To backup or share your dashboard:

1. Dashboard settings (gear icon)
2. JSON Model
3. Copy JSON or click "Save to file"

Troubleshooting

"No data" shown

• Check time range (top right) - data might be outside range
• Verify query in Query Inspector
• Check TimescaleDB has data: SELECT COUNT(*) FROM car_metrics;

Query syntax errors

• Don't use Grafana macros like $__timeFilter() with PostgreSQL
• Use plain SQL with WHERE time > NOW() - INTERVAL '1 hour'

Slow dashboard

• Add index: CREATE INDEX ON car_metrics (time DESC);
• Limit data range in queries
• Use time_bucket() for aggregations