Raspberry Pi Python Robot Class - see http://reefwingrobotics.blogspot.com.au/

RS_Robot.py

#!/usr/bin/python
# RS_Robot.py - Robot Class for the Raspberry Pi 
#
# 4 March 2017 - 1.0 Original Issue
#
# Reefwing Software
# Simplified BSD Licence - see bottom of file.

import RPi.GPIO as GPIO
import os, signal

from time import sleep
from enum import Enum, unique

from RS_Servo import Servo
from RS_Server import Server
from RS_MotorControl import MotorControl

@unique
class Task(Enum):
    HALT         = 1
    REMOTE       = 2
    PATROL       = 3

class Robot():
    # Robot class - includes motor control, 2 servos and a web server
    
    def __init__(self):
        # Create a new robot instance
        print("Robot booting...")
        self.server = Server(self)             # start web server for remote control
        print(self.server)
        self.pan_servo = Servo(5, 3, 11)       # servo which controls ultrasonic pan
        self.tilt_servo = Servo(6, 2, 11)      # servo which controls ultrasonic tilt
        self.motor_control = MotorControl()    # create a new motor control instance
        self.pan_servo.start()                 # start servo PWM
        self.tilt_servo.start()

        # Command method look up table for parse_command()
        self.CMD_DICT = {"f" : self.motor_control.forward,
                         "l" : self.motor_control.left,
                         "r" : self.motor_control.right,
                         "b" : self.motor_control.back,
                         "s" : self.motor_control.stop,
                         "+" : self.motor_control.faster,
                         "-" : self.motor_control.slower,
                         "m" : lambda: self.assign_task(Task.REMOTE),
                         "a" : lambda: self.assign_task(Task.PATROL)}

    def __str__(self):
        # Return string representation of robot
        return "Robot Motor Control: base time - {0} sec, duty - {1}%".format(self.motor_control.base_time, self.motor_control.duty)

    def assign_task(self, TID):
        # Stub - will assign new robot task
        pass

    def parse_command(self, cmd):
        # Process and action command request
        print("Received command: ", cmd)
        try:
            cmd_method = self.CMD_DICT.get(cmd)
        except KeyError:
            print("ERROR:: Unknown Command: ", cmd)
            cmd_method = lambda: self.assign_task(Task.HALT)
        cmd_method()
        
    def test(self):
        # Self Test robot and run diagnostics
        print(self)
        print("Motor Test...")
        self.motor_control.speed(20)
        self.motor_control.right_forward()
        sleep(1)
        self.motor_control.stop()
        sleep(1)
        self.motor_control.left_forward()
        sleep(1)
        self.motor_control.stop()
        print("Servo Test...")
        self.pan_servo.scan()
        self.tilt_servo.scan()
        sleep(2)
        # Move the ultrasonic sensor out of the view of the camera
        print("Moving servos to manual control position")
        self.pan_servo.centre()
        self.tilt_servo.max_dc()
        sleep(1)
        # Stop servo chattering by turning off PWM
        self.pan_servo.stop()
        self.tilt_servo.stop()
        print("Commence video streaming...")
        self.server.start()

    def cleanup(self):
        self.server.cleanup()
        self.motor_control.cleanup()
        self.pan_servo.cleanup()
        self.tilt_servo.cleanup()

def main():
    robot = Robot()     # create a new robot instance

    def endProcess(signum = None, frame = None):
        # Called on process termination. 
        if signum is not None:
            SIGNAL_NAMES_DICT = dict((getattr(signal, n), n) for n in dir(signal) if n.startswith('SIG') and '_' not in n )
            print("signal {} received by process with PID {}".format(SIGNAL_NAMES_DICT[signum], os.getpid()))
        print("\n-- Terminating program --")
        print("Cleaning up PWM and GPIO...")
        robot.cleanup()
        GPIO.cleanup()
        print("Done.")
        exit(0)

    # Assign handler for process exit
    signal.signal(signal.SIGTERM, endProcess)
    signal.signal(signal.SIGINT, endProcess)
    signal.signal(signal.SIGHUP, endProcess)
    signal.signal(signal.SIGQUIT, endProcess)

    robot.test()
    endProcess()

if __name__ == "__main__":
    # execute only if run as a script
    main()

## Copyright (c) 2017, Reefwing Software
## All rights reserved.
##
## Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are met:
##
## 1. Redistributions of source code must retain the above copyright notice, this
##   list of conditions and the following disclaimer.
## 2. Redistributions in binary form must reproduce the above copyright notice,
##   this list of conditions and the following disclaimer in the documentation
##   and/or other materials provided with the distribution.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
## ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
## WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
## DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
## ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
## (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
## LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
## ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
## SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.