ROS2 and Arduino (Teensy 4.1) communication over Ethernet?

[darkextratoasty]

I'm trying to communicate between an Ubuntu 22.04 computer running ROS2 Iron and a Teensy 4.1 over Ethernet, but am not having much luck. On the Ubuntu side, I have ROS2 installed and that's it.

On the Teensy side, I've found ros2arduino and micro_ros_arduino libraries, but am running into issues with both of them.

The micro_ros_arduino library I can't get to build at all. It doesn't appear to be built into either the Arduino IDE or PlatformIO on VSCode.
On the Arduino IDE, I've tried adding it as a ZIP library, but I get Error: 13 INTERNAL: Library install failed: extracting archive: Not a supported archive: unknown. On PlatformIO I can add the library through the HTTPS git clone URL, but when I try to build it, I get

collect2.exe: error: ld returned 1 exit status
*** [.pio\build\teensy41\firmware.elf] Error 1

with absolutely no other errors. I know that error usually means something earlier failed, but there are no other errors in the build output.

The publisher_ethernet_udp example in the ros2arduino library will build and run just fine, but I can't seem to get it to actually publish anything. When using the default Ethernet library, it hangs at the while(Ethernet.linkStatus() != LinkON); line forever. By switching to the QNEthernet library and adding DHCP, I can connect to the local network, get through the ros2::init, and start the spin, but nothing ever publishes. My guess is that it's failing to connect to the ROS2 instance on the Ubuntu machine, but I don't know what's missing to let it do so. I've tried setting the AGENT_IP to the IP address of the Ubuntu machine (which I believe is the correct setting), as well as the IP of the Teensy and just some random IPs for kicks. I don't know what the AGENT_PORT should be set to, but I've tried 11811 and the default 2018. The ros2arduino and QNEthernet code is below:
main.cpp

#include <Arduino.h>
#include <ros2arduino.h>
#include <QNEthernet.h>
using namespace qindesign::network;
#define AGENT_IP   "192.168.1.37"
#define AGENT_PORT 2018 //AGENT port number
#define PUBLISH_FREQUENCY 1 //hz
constexpr uint32_t kDHCPTimeout = 15'000;  // 15 seconds

// UDP port.
EthernetUDP udp;

//this publishstring function never runs
void publishString(std_msgs::String* msg, void* arg) {
  (void)(arg);

  static int cnt = 0;
  sprintf(msg->data, "Hello ros2arduino %d", cnt++);
  Serial.println("Publishing");
}

//this section runs
class StringPub : public ros2::Node {
public:
  StringPub()
  : Node("ros2arduino_pub_node")
  {
    ros2::Publisher<std_msgs::String>* publisher_ = this->createPublisher<std_msgs::String>("arduino_chatter");
    this->createWallFreq(PUBLISH_FREQUENCY, (ros2::CallbackFunc)publishString, nullptr, publisher_);
  }
};

void setup() {
  Serial.begin(115200);
  delay(3000);
  Serial.println("Starting");
  uint8_t mac[6];
  Ethernet.macAddress(mac);
  Serial.printf("MAC = %02x:%02x:%02x:%02x:%02x:%02x\r\n",
         mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

  Serial.printf("Starting Ethernet with DHCP...\r\n");
  if (!Ethernet.begin()) {
    Serial.printf("Failed to start Ethernet\r\n");
    return;
  }
  if (!Ethernet.waitForLocalIP(kDHCPTimeout)) {
    Serial.printf("Failed to get IP address from DHCP\r\n");
    return;
  }

  IPAddress ip = Ethernet.localIP();
  Serial.printf("    Local IP    = %u.%u.%u.%u\r\n", ip[0], ip[1], ip[2], ip[3]);
  ip = Ethernet.subnetMask();
  Serial.printf("    Subnet mask = %u.%u.%u.%u\r\n", ip[0], ip[1], ip[2], ip[3]);
  ip = Ethernet.gatewayIP();
  Serial.printf("    Gateway     = %u.%u.%u.%u\r\n", ip[0], ip[1], ip[2], ip[3]);
  ip = Ethernet.dnsServerIP();
  Serial.printf("    DNS         = %u.%u.%u.%u\r\n", ip[0], ip[1], ip[2], ip[3]);

  ros2::init(&udp, AGENT_IP, AGENT_PORT);
  Serial.println("ros init");
}

void loop() {
  static StringPub StringNode;
  ros2::spin(&StringNode);
}

platformio.ini

[env:teensy41]
platform = teensy
board = teensy41
framework = arduino
lib_deps = 
    robotis-git/ros2arduino@^0.2.1
    https://github.com/ssilverman/QNEthernet.git

Any help or guidance would be appreciated.