Source code for StepperPython.stepper_motion_script

#!/usr/bin/env python

"""\
test_client.py : sample code in Python to communicate with an Arduino running CNC_Shield_Server

Copyright (c) 2015, Garth Zeglin.  All rights reserved. Licensed under the terms
of the BSD 3-clause license.

"""

#================================================================
from __future__ import print_function
import argparse
import time

# This requires a pySerial installation.
#  Package details: https://pypi.python.org/pypi/pyserial,
#  Documentation: http://pythonhosted.org/pyserial/
import serial

#================================================================
[docs]class CncShieldClient(object): """Class to manage a connection to a CNC_Shield_Server running on a serial-connected Arduino. :param port: the name of the serial port device :param verbose: flag to increase console output :param debug: flag to print raw inputs on sconsole :param kwargs: collect any unused keyword arguments """ def __init__(self, port=None, verbose=False, debug=False, **kwargs ): # initialize the client state self.arduino_time = 0 self.position = [0, 0, 0] self.target = [0, 0, 0] self.verbose = verbose self.debug = debug self.awake = False # open the serial port, which should also reset the Arduino self.port = serial.Serial( port, 115200, timeout=5 ) if self.verbose: print("Opened serial port named", self.port.name) print("Sleeping briefly while Arduino boots...") # wait briefly for the Arduino to finish booting time.sleep(2) # units are seconds # throw away any extraneous input self.port.flushInput() return
[docs] def close(self): """Shut down the serial connection to the Arduino, after which this object may no longer be used.""" self.port.close() self.port = None return
def _wait_for_input(self): line = self.port.readline().rstrip() if line: elements = line.split() if self.debug: print("Received: '%s'" % line) if elements[0] == 'txyz': self.arduino_time = int(elements[1]) self.position = [int(s) for s in elements[2:]] elif elements[0] == 'awake': self.awake = True elif elements[0] == 'dbg': print("Received debugging message:", line) else: print("Unknown status message: ", line) return def _send_command(self, string): if self.verbose: print("Sending: ", string) self.port.write( string+'\n') return
[docs] def motor_enable( self, value=True): """Issue a command to enable or disable the stepper motor drivers.""" self._send_command( "enable 1" if value is True else "enable 0" ) return
[docs] def wait_for_wakeup(self): """Issue a status query and wait until an 'awake' status has been received.""" while self.awake is False: self._send_command( "ping" ) self._wait_for_input()
[docs] def move_to(self, position): """Issue a command to move to a [x, y, z] absolute position (specified in microsteps) and wait until completion. :param position: a list or tuple with at least three elements """ self._send_command( "goto %d %d %d" % tuple(position)) self.target = position while self.position[0] != position[0] or self.position[1] != position[1] or self.position[2] != position[2]: self._wait_for_input() if self.verbose: print ("Position:", self.position) return
#================================================================ # The following section is run when this is loaded as a script. if __name__ == "__main__": # Initialize the command parser. parser = argparse.ArgumentParser( description = """Simple test client to send data to the CNC_Shield_Server on an Arduino.""") parser.add_argument( '-v', '--verbose', action='store_true', help='Enable more detailed output.' ) parser.add_argument( '--debug', action='store_true', help='Enable debugging output.' ) parser.add_argument( '--extra', action='store_true', help='Unused.') parser.add_argument( '-p', '--port', default='/dev/tty.usbmodem1411', help='Specify the name of the Arduino serial port device (default is /dev/tty.usbmodem1411).') # Parse the command line, returning a Namespace. args = parser.parse_args() # Convert the Namespace to a set of keyword arguments and initialize the # client object. Note that it will ignore extraneous values, e.g., from # additional command argument inputs unneeded by this object. client = CncShieldClient(**vars(args)) # Begin the motion sequence. This may be safely interrupted by the user pressing Control-C. try: print("Waiting for wakeup.") client.wait_for_wakeup() print("Beginning movement sequence.") client.motor_enable() client.move_to([1000, 2000, 3000]) client.move_to([0, 0, 0]) client.move_to([1000, 2000, 3000]) client.move_to([0, 0, 0]) client.move_to([3000, 2000, 1000]) client.move_to([0, 0, 0]) client.move_to([3000, 2000, 1000]) client.move_to([0, 0, 0]) except KeyboardInterrupt: print("User interrupted motion.") # Issue a command to turn off the drivers, then shut down the connection. client.motor_enable(False) client.close()