[clopema] IO Pulse

io_pulse.py

#!/usr/bin/env python

"""
io_pulse.py


Libor Wagner on April  3, 2013
"""

# Constants
NODE_NAME = "io_pulse"
NODE_PACKAGE = "clopema_utilities"

# Defalue ROS imports
import roslib; roslib.load_manifest(NODE_PACKAGE)
import rospy
import sys

# Import message types
from clopema_motoros.srv import WriteIO, IOPulse, IOPulseResponse

# The IO Pulse class
class IOPulseNode(object):

    def __init__(self):
        # Get parameter
        self._write_io_srv = rospy.get_param('~write_io_srv', 'write_io')

        # Regirster service proxy
        self._write_io = rospy.ServiceProxy(self._write_io_srv, WriteIO)

        # Advertise service
        self._io_pulse = rospy.Service('~io_pulse', IOPulse, self.__handle_io_pulse)

    def __handle_io_pulse(self, req):
        self._write_io(req.address, req.value)
        rospy.sleep(req.length)
        self._write_io(req.address, not req.value)
        return IOPulseResponse()

def usage(argv):
    import os
    print "usage: ", os.path.basename(argv[0]), "[-h] [PARAMS]"
    print
    print "OPTIONS"
    print " -h      Show this message"
    print
    print "PARAMS"
    print " _write_io_srv     IO Interface service name"

if __name__ == '__main__':
    rospy.init_node(NODE_NAME)
    argv = rospy.myargv(argv=sys.argv)
    if '-h' in argv: usage(argv)

    io_pulse = IOPulse()
    rospy.spin()

IOPulse.srv

int32   address
bool    value
float32 length
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