Mission Instrumentation

PI1 — Instrumented Payload Bus (Level 1: Proof & Confidence)

Mission Goal

Bring up a Raspberry Pi “payload bus” that reads at least one sensor and outputs a clean, human-readable status line on demand.

Why This Matters

Before advanced missions, you must prove basic payload bus health: power, sensor readout, and predictable status output.

What Data You Collect

• Basic sensor reading (choose one): temperature, humidity, pressure, light, or CPU temperature
• Timestamp
• System status: uptime, disk free (optional)

Hardware / Software Needed

• Raspberry Pi (any model with Raspberry Pi OS)
• Power supply, microSD card
• Optional sensor: BME280 / DHT / light sensor (or use CPU temperature if no sensor)
• Python 3

Inputs From Other Teams

• Data: Recommend a standard status line format.
• Command & Control: Define “payload bus alive” readiness check.
• Comms: If sending status over network, agree message format and endpoint.

What You Must Produce (Deliverables)

• A Python script that prints a status line reliably.
• A short README: how to run it, what it outputs.
• A screenshot/photo of terminal output.

Step-by-Step Build

1. Boot Raspberry Pi OS and open Terminal.
2. Create a folder: mission_instrumentation/pi1.
3. Write a Python script that:
   • Gets timestamp
   • Reads a sensor value (or CPU temperature)
   • Prints a single formatted status line
4. Run the script 5 times. Confirm output format is identical each time.
5. Optional: add a simple CLI flag like --json to output JSON.

Data Format / Output

Recommended single-line output:

• TS=2025-12-29T19:44Z | TEMP_C=23.1 | UPTIME_S=1234

Analysis Ideas

• Collect 20 samples and compute average/min/max.
• Compare CPU temperature before/after workload.
• Check sensor stability over 10 minutes.

Success Criteria

• Script runs without errors and produces a clean status line.
• Data fields are labeled and units are clear.
• Team can explain what would make the data unreliable (warm hands, CPU load, poor sensor wiring).

Evidence Checklist

• Screenshot/photo of output
• Script file saved and named clearly
• README with run instructions

Safety & Privacy

• Power safety: correct PSU, avoid exposed wires.
• No personal identifiers in logs.
• Handle electronics with dry hands; keep liquids away.

Common Failure Modes

• Sensor wiring incorrect (3.3V vs 5V confusion).
• Missing libraries or wrong I2C configuration.
• Output changes format across runs (hard to parse later).

Stretch Goals

• Add JSON output mode.
• Add a “health” flag (OK/WARN) based on thresholds.
• Write a systemd service to run at boot.