Quick Start

Before you can run any ROS 2 commands on your robot, you need to connect to the Raspberry Pi over the network. The robot obtains an IP address via DHCP when powered on. The following commands help you discover that IP and open an SSH session as the rcr user.

To give each robot a unique identity on your network you should set the system hostname. These commands modify the cloud‑init configuration to prevent overwriting the hostname, set the hostname files, and apply the changes.

In the editor, find the line beginning with preserve_hostname and set it to true:

preserve_hostname: true

Save and exit (Ctrl+O, Enter, Ctrl+X).

Replace occurrences of the old hostname with your robot’s desired name (e.g. rcr001). In /etc/hosts update the line beginning with 127.0.1.1 to reference your new hostname.

For reliable communication between your development computer and the robot you may want to assign a static IP address and configure Wi‑Fi credentials. The Pi uses Netplan for network management. Edit the configuration and apply it, then verify connectivity.

Adjust the file to specify your network settings. For example:

network:
  version: 2
  ethernets:
    eth0:
      dhcp4: false
      addresses: [192.168.1.42/24]
      gateway4: 192.168.1.1
      nameservers:
        addresses: [8.8.8.8,8.8.4.4]
  wifis:
    wlan0:
      dhcp4: true
      access-points:
        "YourSSID":
          password: "YourWiFiPassword"

Save the file and exit the editor.

To avoid conflicts when running multiple robots on the same network, you must assign a unique name and namespace to your robot. ROS 2 uses these to prefix all topics and nodes so that multiple robots can share the same network without collisions.

If your micro‑ROS firmware initializes the node with a namespace, you must update the source code as well. Open the RosInterface.cpp file in the firmware directory and change the third argument of rclc_node_init_default to your robot’s name:

```bash {id:”namespace:edit-firmware”, test:false}
cd ~/repos/common_platform/firmware/closed_loop/
sudo nano RosInterface.cpp

In the file, find the line that looks similar to:

```cpp
rclc_node_init_default(&node, "micro_ros_arduino_node", "", &support);

Replace the empty string with your robot name (e.g. rcr00n):

rclc_node_init_default(&node, "micro_ros_arduino_node", "rcr00n", &support);

Save the file, then recompile and flash the firmware using the Teensy flashing procedure so the change takes effect.

The closed‑loop motor controller firmware for the robot runs on a Teensy 4.0 microcontroller. Follow these steps to compile and upload the firmware using arduino-cli and teensy_loader_cli.