prop-teststand

Server application for QRET's propulsion test stand. Discovers and communicates with ESP32 sensor/control devices over a custom binary TCP protocol, collects sensor data, controls valves, manages IP cameras, and exposes everything through a REST API and CLI.

System Architecture

The server is designed to run on a Raspberry Pi (or any Linux machine / WSL) as a headless hub between ESP32 devices and any number of clients.

flowchart LR
    ESP1[ESP32<br>Sensors & Valves] -->|TCP :50000| Pi
    ESP2[ESP32<br>Sensors & Valves] -->|TCP :50000| Pi
    Cam[IP Cameras] -->|ONVIF / RTSP| Pi

    Pi[Server<br>Raspberry Pi]

    subgraph Clients
      direction TB
      GUI[Desktop GUI]
      Web[Web Client]
      API[REST / WebSocket]
    end

    Pi -->|FastAPI :8000| GUI
    Pi -->|WebRTC / RTSP| Web
    Pi -->|HTTP / WS| API

    Here((YOU ARE HERE)) --> Pi:::youAreHere
    classDef youAreHere stroke:red, stroke-width:6px;
    linkStyle 5 stroke:red,stroke-width:4px
    style Here fill:transparent,stroke:none,color:red;

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Services

Service	Description
server	Main application — device discovery (SSDP), TCP listener, FastAPI, CLI
redis	Logging pub/sub and real-time data relay
media	MediaMTX RTSP/WebRTC relay for camera streams
logs	Log aggregator that reads from Redis channels
mockdevice	Mock client device (only available in development)

Setup

Prerequisites

• Docker (recommended)
• Or: Python 3.11+ with uv

Development (Docker)

docker compose -f compose.dev.yml up

This starts all necessary services with file watching — code changes in libqretprop/ and config.yaml trigger automatic restarts.

To also run the mock device for testing, add --profile mock

Production (Docker)

docker compose -f compose.prod.yml up -d

Pulls pre-built images from ghcr.io/queens-rocket-engineering-team/.

Local (No Docker)

uv pip install -e .          # core dependencies
uv pip install -e ".[gui]"   # optional: GUI tools (PySide6)

make build-protocol # build qlcp library for binary protocol

start_server                 # start the server

Redis must be running separately for logging to work.

Configuration

The server reads config.yaml for service connections and camera definitions:

accounts:
  redis:
    username: server
    password: ...
  camera:
    username: propcam
    password: ...

services:
  redis:
    ip: localhost
    port: 6379
  mediamtx:
    ip: localhost
    api_port: 9997
    webrtc_port: 8889

cameras:
  - ip: 192.168.1.5
    onvif_port: 2020

Override the path with the PROP_CONFIG environment variable (defaults to ./config.yaml).

ESP32 devices configure themselves — each device sends a JSON CONFIG packet on connection describing its sensors and controls.

CLI Tools

Command	Description
start_server	Start the main server
see_logs	View real-time logs from Redis (-e errors, -d debug, -s system)
mock_device	Simulate an ESP32 device for testing
full_gui	Full PySide6 control panel (requires gui extra)

Once the server is running, an interactive CLI provides commands like discover, list, stream <device> <Hz>, control <device> <name> <state>, and estop.

Protocol

Devices communicate using a custom binary protocol over TCP (port 50000) and UDP (port 50001). Devices are discovered via SSDP multicast on 239.255.255.250:1900. On discovery, the device opens a TCP connection to the server and sends its CONFIG. The server then time-syncs the device and normal operation begins (streaming, control commands, heartbeats).

For more information on protocol specifications, see ctl-qlcp-lib.

ESP32 Setup

For the microcontroller side of this project, see prop-esp32-logger.

IDE Setup

This project is intended to be opened in VSCode. Install the recommended extensions when prompted.