Cloud Server Overview

The Backend is the ground-side counterpart to the car's Telemetry Node: a Python service (the "Telemetry Middleman") that receives the UDP CSV stream, fans it out to three destinations in real time, tracks laps independently from GPS, and exposes a web dashboard and control API. It runs in Docker alongside InfluxDB and Grafana on the pit server.

What it does

• Ingests UDP CSV packets from the car, see Middleman.
• Streams live to Grafana with no queueing latency, see Grafana.
• Stores every field to InfluxDB for later analysis, see InfluxDB.
• Forwards to Marple, per session, about once a second, see Middleman.
• Tracks laps from GPS coordinates, with a runtime-configurable finish line, see Lap Tracking.
• Serves a web dashboard and REST control API.

Data flow

Threads at a glance

Thread	Reads	Does	Docs
activity-monitor	packet arrival	Declares the stream active/inactive	Middleman
udp-receiver	UDP socket	Parses CSV, pushes to Grafana inline, fans out to 3 queues	Middleman
influx-writer	influx_q	Batches points into the telemetry bucket	InfluxDB
marple-sender	marple_q	Flushes to Marple once a second, per session	Middleman
influx-stats	stats_q	Writes middleman health metrics to the stats bucket	InfluxDB
stats-reporter	counters	Prints a status table, feeds stats_q	Middleman
lap-tracker	analysis_q	Detects finish-line crossings, writes lap events	Lap Tracking
web-api	HTTP	FastAPI dashboard and control endpoints	Middleman

Every thread reads its configuration from one typed Config object (config.py), sourced from .env. The CSV column layout is defined once in schema.py, mirroring the firmware's CSV output; that's the only file to touch if the wire format changes. See Server Setup for deployment.