Set Datum

Set the datum. The datum is the reference coordinate of the navigations "map" frame. The XY position of the robot is relative to this location.

• Service Name: localization/set_datum

• Service Type: clearpath_localization_msgs/srv/SetDatum

Python

from clearpath_config.common.utils.yaml import read_yaml
from clearpath_localization_msgs.srv import SetDatum
import rclpy
from rclpy.node import Node

ROBOT_CONFIG_PATH = '/etc/clearpath/robot.yaml'
LOGGING_NAME = 'SetDatum'

# TODO: Enter your datum latitude/longitude
DATUM_LATITUDE: float =
DATUM_LONGITUDE: float =


class SetDatumCLient(Node):

    def __init__(self, namespace: str):
        super().__init__('set_datum_client')
        self._set_datum_client = self.create_client(SetDatum, f'/{namespace}/localization/set_datum')

        while not self._set_datum_client.wait_for_service(timeout_sec=2.0):
            self.get_logger().info(f'[{LOGGING_NAME}] /{namespace}/localization/set_datum service not available, waiting again...')

    def set_datum(self, latitude, longitude):
        req = SetDatum.Request()
        req.lat = latitude
        req.lon = longitude
        self.future = self._set_datum_client.call_async(req)
        self.future.add_done_callback(self.set_datum_srv_response_cb)

    def set_datum_srv_response_cb(self, future):
        try:
            response = future.result()
            if response.success:
                self.get_logger().info(f'[{LOGGING_NAME}] Set datum successfully!')
            else:
                self.get_logger().error(f'[{LOGGING_NAME}] Failed to set datum')
        except Exception as e:
            self.get_logger().error(f'[{LOGGING_NAME}] Service call failed: {e}')

        self.destroy_node()
        rclpy.shutdown()


def main(args=None):
    rclpy.init(args=args)
    robot_config = read_yaml(ROBOT_CONFIG_PATH)
    namespace = robot_config['system']['ros2']['namespace']

    set_datum_client = SetDatumCLient(namespace)
    set_datum_client.set_datum(DATUM_LATITUDE, DATUM_LONGITUDE)

    rclpy.spin(set_datum_client)


if __name__ == '__main__':
    main()

C++

#include "rclcpp/rclcpp.hpp"
#include "clearpath_localization_msgs/srv/set_datum.hpp"

#include <chrono>
#include <cstdlib>
#include <memory>
#include <yaml-cpp/yaml.h>

const double DATUM_LAT = 43.5009;
const double DATUM_LON = -80.5474;

using namespace std::chrono_literals;

int main(int argc, char **argv)
{
  rclcpp::init(argc, argv);
  
  YAML::Node robot_config = YAML::LoadFile("/etc/clearpath/robot.yaml");
  std::string namespace_ = robot_config["system"]["ros2"]["namespace"].as<std::string>();

  std::shared_ptr<rclcpp::Node> node = rclcpp::Node::make_shared("set_datum_client");
  rclcpp::Client<clearpath_localization_msgs::srv::SetDatum>::SharedPtr client =
    node->create_client<clearpath_localization_msgs::srv::SetDatum>("/" + namespace_ + "/" + std::string("localization/set_datum"));

  auto request = std::make_shared<clearpath_localization_msgs::srv::SetDatum::Request>();
  request->lat = DATUM_LAT;
  request->lon = DATUM_LON;

  while (!client->wait_for_service(2s)) {
    if (!rclcpp::ok()) {
      RCLCPP_ERROR(rclcpp::get_logger("set_datum_client"), "Interrupted while waiting for the service. Exiting.");
      return 0;
    }
    RCLCPP_INFO(rclcpp::get_logger("set_datum_client"), "/%s/localization/set_datum service not available, waiting again...", namespace_.c_str());
  }

  auto result = client->async_send_request(request);

  // Wait for the result.
  if (rclcpp::spin_until_future_complete(node, result) ==
    rclcpp::FutureReturnCode::SUCCESS)
  {
    if (result.get()->success)
    {
      RCLCPP_INFO(rclcpp::get_logger("set_datum_client"), "Datum set successfully!");
    }
    else
    {
      RCLCPP_ERROR(rclcpp::get_logger("set_datum_client"), "Failed to set datum!");
    }
  } else {
    RCLCPP_ERROR(rclcpp::get_logger("set_datum_client"), "Failed to call service /%s/localization/set_datum", namespace_.c_str());
  }

  rclcpp::shutdown();
  return 0;
}