Main.cpp

// based on https://github.com/micro-ROS/micro_ros_arduino/blob/humble/examples/micro-ros_publisher_ethernet/micro-ros_publisher_ethernet.ino

#include <micro_ros_arduino.h>

#include <stdio.h>
#include <rcl/rcl.h>
#include <rcl/error_handling.h>
#include <rclc/rclc.h>
#include <rclc/executor.h>
#include <std_msgs/msg/int32.h>

#if !defined(TARGET_PORTENTA_H7_M7)
#error This example is only available for Arduino Portenta
#endif

rcl_publisher_t publisher;
std_msgs__msg__Int32 msg;
rclc_support_t support;
rcl_allocator_t allocator;
rcl_node_t node;

#define LED_PIN LEDR

#define RCCHECK(fn) { rcl_ret_t temp_rc = fn; if((temp_rc != RCL_RET_OK)){error_loop();}}
#define RCSOFTCHECK(fn) { rcl_ret_t temp_rc = fn; if((temp_rc != RCL_RET_OK)){}}

void error_loop(){
  while(1){
    digitalWrite(LED_PIN, !digitalRead(LED_PIN));
    delay(100);
  }
}

void setup() {
   byte arduino_mac[] = { 0xAA, 0xBB, 0xCC, 0xEE, 0xDD, 0xFF };

  IPAddress arduino_ip(10, 100, 0, 177);
  IPAddress agent_ip(10, 100, 0, 111);
  set_microros_native_ethernet_transports(arduino_mac, arduino_ip, agent_ip, 9999);

  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, HIGH);

  delay(2000);

  allocator = rcl_get_default_allocator();

  //create init_options
  RCCHECK(rclc_support_init(&support, 0, NULL, &allocator));

  // create node
  RCCHECK(rclc_node_init_default(&node, "micro_ros_arduino_ethernet_node", "namespace", &support));

  // create publisher
  RCCHECK(rclc_publisher_init_best_effort(
    &publisher,
    &node,
    ROSIDL_GET_MSG_TYPE_SUPPORT(std_msgs, msg, Int32),
    "topic_name"));

  msg.data = 0;
}

void loop() {
    RCSOFTCHECK(rcl_publish(&publisher, &msg, NULL));
    msg.data++;
    delay(100);
}