modded_publisher_member_function.py

# Copyright 2016 Open Source Robotics Foundation, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import rclpy
from rclpy.node import Node

import py_pubsub.ultrasonic_distance as p

from std_msgs.msg import String

from sensor_msgs.msg import Range

class MinimalPublisher(Node):

    def __init__(self):
        super().__init__('minimal_publisher')
        self.publisher_ = self.create_publisher(Range, 'distance', 10)
        timer_period = 0.1  # seconds
        self.timer = self.create_timer(timer_period, self.timer_callback)
        self.i = 0

    def timer_callback(self):
        # msg = String()
        # msg.data = 'Hello World: %d' % self.i
        # self.publisher_.publish(msg)
        # self.get_logger().info('Publishing: "%s"' % msg.data)
        # self.i += 1
        rg = p.distance()
        r = Range()
        r.header.stamp = self.get_clock().now().to_msg()
        r.header.frame_id = "/sonar_link"
        r.radiation_type = 0
        r.field_of_view = .31
        r.min_range = .02
        r.max_range = 1.4
        r.range = rg
        self.publisher_.publish(r)

def main(args=None):
    rclpy.init(args=args)

    minimal_publisher = MinimalPublisher()

    rclpy.spin(minimal_publisher)

    # Destroy the node explicitly
    # (optional - otherwise it will be done automatically
    # when the garbage collector destroys the node object)
    minimal_publisher.destroy_node()
    rclpy.shutdown()


if __name__ == '__main__':
    main()