ultrasonic sensor

1.アドゥーエノ設定

2.ROS上でのシリアル通信

1.ポート権限の取得

2.リリーステーマ

#!/usr/bin/env python

import serial, time, rospy, re
from std_msgs.msg import Int32

ser_front = serial.Serial(
    port='/dev/ttyUSB0',	# 신호를 받을 포트
    baudrate=9600,		# 포트 속도
    )

def read_sensor():
    serial_data = ser_front.readline()
    ser_front.flushInput()
    ser_front.flushOutput() 
    ultrasonic_data = int(filter(str.isdigit, serial_data))
    msg.data = ultrasonic_data
 
if __name__ == '__main__':

    rospy.init_node('ultrasonic_pub', anonymous=False) # initialize node
    pub = rospy.Publisher('ultrasonic', Int32, queue_size=1)

    msg = Int32() # message type
    while not rospy.is_shutdown():
        read_sensor() 
        pub.publish(msg) # publish a message
        time.sleep(0.2)
   
    ser_front.close()	# 포트는 꼭 닫자

3.話題購読

#!/usr/bin/env python

import rospy
from std_msgs.msg import Int32

def callback(msg):
    print(msg.data)

rospy.init_node('ultrasonic_sub')
sub = rospy.Subscriber('ultrasonic', Int32, callback)

rospy.spin()

4.起動ファイル

<launch>
    <node pkg="ultrasonic" type="ultrasonic_pub.py" name="ultrasonic_pub"/>
    <node pkg="ultrasonic" type="ultrasonic_sub.py" name="ultrasonic_sub" output="screen"/>
</launch> 

5.結果