Hello.SIM

Hello.SIM.py

import rclpy
from rclpy.node import Node

from std_msgs.msg import Float32


class MinimalPublisher(Node):

    def __init__(self):
        super().__init__('minimal_publisher')
        self.publisher_1 = self.create_publisher(Float32, '/hellosim/motor_1', 1)
        self.publisher_2 = self.create_publisher(Float32, '/hellosim/motor_2', 1)
        self.publisher_3 = self.create_publisher(Float32, '/hellosim/motor_3', 1)
        self.publisher_4 = self.create_publisher(Float32, '/hellosim/motor_4', 1)
        timer_period = 0.5  # seconds
        self.timer = self.create_timer(timer_period, self.timer_callback)
        self.i = 0

    def timer_callback(self):
        msg = Float32()
        msg.data = 1.0
        self.publisher_1.publish(msg)
        self.publisher_2.publish(msg)
        msg.data = -1.0
        self.publisher_3.publish(msg)
        self.publisher_4.publish(msg)
        self.get_logger().info('Publishing: "%s"' % msg.data)
        self.i += 1


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()