Micro ros image subscriber issue

[ZaGabriel]

Issue template

• Hardware description: ESP32
• RTOS:
• Installation type: arduino ide
• Version or commit hash: humble

Steps to reproduce the issue

Expected behavior

I want a subscriber listen to a image topic.

Actual behavior

rclc_executor_spin_some returns RMW_RET_ERROR.

Additional information

I've working on it for hours, have no idea how to subscribe to a image topic, but I've successes on publish an image topic on micro ros. Even if I let subscription_callback() do nothing the rclc_executor_spin_some will still returns RMW_RET_ERROR.

here is my code on subscribe an image topic :

#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>
#include <sensor_msgs/msg/image.h>

rcl_subscription_t subscriber;
sensor_msgs__msg__Image msg;
rclc_executor_t executor;
rclc_support_t support;
rcl_allocator_t allocator;
rcl_node_t node;
rcl_timer_t timer;

#define LED_PIN 13

#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 subscription_callback(const void * msgin){  
  
}

void setup() {
  set_microros_transports();
  
  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_node", "", &support));

  // create subscriber
  RCCHECK(rclc_subscription_init_default(
    &subscriber,
    &node,
    ROSIDL_GET_MSG_TYPE_SUPPORT(sensor_msgs, msg, Image),
    "micro_ros_subscriber"));

  // create executor
  RCCHECK(rclc_executor_init(&executor, &support.context, 1, &allocator));
  RCCHECK(rclc_executor_add_subscription(&executor, &subscriber, &msg, &subscription_callback, ON_NEW_DATA));
}

void loop() {
  delay(100);
  RCCHECK(rclc_executor_spin_some(&executor, RCL_MS_TO_NS(100)));
}

[hippo5329]

You will need to handle message memory allocation.

https://micro.ros.org/docs/tutorials/advanced/handling_type_memory/