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11. Operational Guide

This guide provides the primary instructions for daily operation of the JetRacer autonomous platform, including startup, mission control, and safety procedures.

Quick Startup (Sentinel Mode)

The robot is configured to boot automatically into Sentinel Mode. In this state, it is "Ready but Idle"—waiting for your controller to trigger a mission.

  1. Power On: Connect the batteries and flip the Jetson Nano power switch.
  2. Wait for Ready: Observe the onboard OLED display. When it shows "MISSION: IDLE", the robot is ready.
  3. Launch: Use the Gamepad to start a mission (see controls below).

Mission Controls (Gamepad)

The standard Waveshare Gamepad matches the following layout for mission management:

Action Combination Result
Launch Autonomy SELECT + START Starts Full Autonomy (LiDAR + Camera + YOLO)
Launch Mapping SELECT + X Starts SLAM and Navigation
Emergency Halt MODE (Center) Kills all active missions and stops all motors

Teleoperation (Manual Override)

Manual driving is always active as a background safety layer. You can override any autonomous mission at any time by simply using the gamepad.

  • Trigger: Hold the Deadman Switch (L2).
  • Priority: High. Pressing L2 will immediately "mute" the Autonomy/SLAM AI and give you direct control of the wheels.
  • Controls (RC Style):
  • Right Stick Vertical: Forward / Backward Speed
  • Left Stick Horizontal: Steering Angle

[!WARNING] Safety Gating: If you release the L2 button while in manual mode, the robot will immediately stop, even if an autonomous mission is running.

Diagnostic Feedback (OLED)

The onboard display provides real-time telemetry to prevent "blind" operation:

  • Mission: Shows the currently active ROS 2 launch.
  • IP: Used for SSH or Foxglove connection.
  • BAT: Total battery voltage. Halt immediately if < 9.6V.
  • CPU: Nano temperature. Throttling starts at 82°C.

Autostart Management

The robot uses a systemd service to manage boot logic.

  • Check Service Status: sudo systemctl status jetracer.service
  • View Live Logs: journalctl -u jetracer.service -f
  • Manual Start/Stop: sudo systemctl [start|stop|restart] jetracer.service

[!TIP] Pro-Tip: If the LiDAR is spinning but the OLED says "IDLE", check the /sentinel/status topic to ensure the relay node is communicating properly.