Interactive Car Systems Diagram

How data, commands and power move through the Racerbot car: sensors into the Jetson, driving commands out to the VESC, motor and servo, and the battery rails underneath - with the actual ROS 2 topics on every wire.

Click any component for what it does and the topics it touches. Use the layer buttons to trace one kind of flow at a time.

Ethernet · /scan USB 3 · /camera telemetry · /sensors · /odom USB · /joy serial · /ackermann_cmd 3‑phase PPM/PWM 14.8 V battery bus regulated DC Logitech F710 gamepad · driver station Hokuyo UST-10LX 270° LiDAR · 40 Hz RealSense D435i colour + depth + IMU Jetson Orin Nano Super ROS 2 Jazzy · Ubuntu 24.04 joy_node · urg_node · realsense gap_follow · pure_pursuit ackermann_mux · vesc_driver vesc_to_odom VESC 6 MkVI motor controller serial /dev/sensors/vesc Drive motor brushless · rear wheels Steering servo PPM/PWM from VESC 4S LiPo battery 14.8 V · LiPo SOP applies Power board XT30 in, rails out VESC bus + regulated DC

Pick a component

The diagram is the real Car 2 wiring: the same nodes, topics and ports you will meet in the docs. Car 1 runs the same software with a USB LiDAR and a webcam instead. Click a box to read about it.

The chain in words

  1. The gamepad produces /joy; manual teleop turns it into a steering-and-speed command on /teleop. Autonomy nodes (follow-the-gap, pure pursuit) publish their own decisions on /drive.
  2. ackermann_mux picks exactly one command source. The human always wins: teleop has priority 100, autonomy 10.
  3. The winning command leaves as /ackermann_cmd and becomes raw motor and servo numbers on /commands/motor/speed and /commands/servo/position.
  4. vesc_driver_node sends those down a serial cable to the VESC, which drives the motor with three-phase power and the steering servo with PPM/PWM.
  5. The LiDAR publishes /scan over Ethernet the whole time, whether the car drives or not. The VESC reports back up the same serial line and vesc_to_odom_node turns that into /odom.
  6. Underneath it all, the LiPo feeds the power board: battery bus to the VESC, regulated DC to the Jetson. Nothing above moves without it.

Source of truth: the car workspace docs - architecture.md on GitHub.