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Advanced Usage & Workflows

1. Wide vs Narrow Format

The database stores telemetry in wide format: each CAN signal is its own column. This is faster to query and requires no pivot step.

import slicks
from datetime import datetime

start = datetime(2025, 9, 28, 12, 0)
end   = datetime(2025, 9, 28, 14, 0)

# Wide format (default, preferred) — direct column access
df = slicks.fetch_telemetry(start, end, ["INV_Motor_Speed", "PackCurrent"], schema="wide")

# Narrow format (legacy EAV) — only for old data that was never migrated
df = slicks.fetch_telemetry(start, end, ["INV_Motor_Speed", "PackCurrent"], schema="narrow")

Use schema="wide" for all new work.

2. Dynamic Sensor Discovery

Not sure what sensors are available? With wide format, discovery is instant — it reads column metadata rather than scanning data rows.

from slicks import discover_sensors

# Wide: instant metadata lookup (no time range needed)
available_sensors = discover_sensors(None, None, schema="wide")

print(f"Found {len(available_sensors)} sensors:")
for sensor in available_sensors:
    print(f" - {sensor}")

3. Managing Environments

You often need to switch between Development, Testing, and Production databases, or switch to a local replay server.

Option A: Environment Variables (Best for CI/CD)

Set these in your shell or .env file before running python:

export INFLUX_URL="http://production-server:8086"
export INFLUX_DB="Season2026_Final"

Option B: Runtime Configuration (Best for Scripts/Notebooks)

import slicks

slicks.connect_influxdb3(
    url="http://192.168.1.50:9000",
    db="DynoTest_Day1"
)

4. Bulk Export for CSV Analysis

If you need to hand off data to the aerodynamics team who uses Excel/MATLAB, use the bulk fetcher. It handles day-by-day chunking to avoid crashing the computer.

from slicks import bulk_fetch_season

# Exports entire date range to a single CSV
bulk_fetch_season(start, end, output_file="full_weekend_data.csv")

5. Writing CAN Data (Wide Format)

If you're ingesting raw CAN bus data (e.g., from a replay script or live logger), use WideWriter. It decodes CAN frames using a DBC file and writes them as wide format line protocol.

from slicks import WideWriter

writer = WideWriter(
    url="http://localhost:8086",
    token="my-token",
    bucket="WFR26",
    measurement="WFR26",
    dbc_path="path/to/WFR26.dbc",
)

# Decode and queue a CAN frame
writer.decode_and_queue(can_id=0x200, data=bytes([0x01, 0x02, ...]), ts_ns=timestamp_ns)

# Flush remaining data when done
writer.close()

Each decoded CAN message becomes one row with all of its signals as fields:

WFR26,messageName=BMS_Status,canId=512 PackCurrent=-3264.0,SOC=85.0 1700000000000000000

6. Customizing Movement Detection

If you are analyzing Charging or Static Testing, the default movement filter will hide your data. Disable it:

# Fetch Battery Current even when car is stopped
df = slicks.fetch_telemetry(
    start, end,
    signals="PackCurrent",
    filter_movement=False
)