How to spin ROS2 publisher node and non-ROS function asynchronously?
Note: Dup of https://github.com/ros2/rclpy/issues/872.
Hi, I'd like to spin a publisher node with non-ros code (in this case, MAVSDK-Python) asynchronously.
So far, I cannot find a way to do so.
Is there any way to achieve it?
code:
import rclpy
from rclpy.node import Node
from std_msgs.msg import String
import asyncio
from mavsdk import System
async def run(node):
drone = System()
await drone.connect(system_address="serial:///dev/ttyACM0")
asyncio.ensure_future(print_battery(drone, node))
async def print_battery(drone, node):
async for battery in drone.telemetry.battery():
battery_stat = battery.remaining_percent
node.battery_percent = battery_stat # update
print(f"battery: {node.battery_percent}, i: {node.i}")
class MinimalPublisher(Node):
def __init__(self):
super().__init__('minimal_publisher')
self.publisher_ = self.create_publisher(String, 'topic', 10)
timer_period = 0.5 # seconds
self.timer = self.create_timer(timer_period, self.timer_callback)
self.i = 0
self.battery_percent = None
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
async def spin_once(minimal_publisher):
rclpy.spin_once(minimal_publisher)
def main(args=None):
rclpy.init(args=args)
minimal_publisher = MinimalPublisher()
# rclpy.spin_once(minimal_publisher)
asyncio.ensure_future(spin_once(minimal_publisher))
asyncio.ensure_future(run(minimal_publisher))
asyncio.get_event_loop().run_forever()
# 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()
output (what I expected: printing battery condition and Hello World with increasing iteration number):
➜ ~ python3 pub.py
[INFO] [1641399256.034609091] [minimal_publisher]: Publishing: "Hello World: 0"
battery: -0.009999999776482582, i: 1
battery: -0.009999999776482582, i: 1
battery: -0.009999999776482582, i: 1
battery: -0.009999999776482582, i: 1