Script for Toggling a CHIP GPIO to turn on/of Relay that powers a Pinewood Derby Car

chipwood_derby.py

#!/usr/bin/env python

# Python Controlled, CHIP Powered Pinewood Derby Car
# Robert Wolterman, 2017

# Module Imports
import CHIP_IO.GPIO as GPIO

# Global Variables
PIN_TO_USE = "XIO-P0"

# Functions
def Setup(pin):
    # We setup the GPIO we want as an output
    GPIO.setup(pin, GPIO.OUT)

def Cleanup(pin):
    # We want to clean everything up
    GPIO.cleanup(pin)

def ToggleRelay(pin, state):
    # We are assuming that the relay needs to go
    # high to enable and low to disable
    if state:
        print("\n* STARTING THE MOTOR *\n")
        GPIO.output(pin, GPIO.HIGH)
    else:
        print("\n* STOPPING THE MOTOR *\n")
        GPIO.output(pin, GPIO.LOW)

def GetUserOptionAndDoTask(pin):
    # Here we're going to print our menu to start/stop the relay
    print("** CHIPWOOD DERBY **")
    print("What would you like to do: ")
    print(" 1 - START!")
    print(" 2 - STOP!")
    print(" q - Quit")
    myopt = raw_input("Enter Option: ")
    while myopt not in ["1", "2", "q", "Q"]:
        print("** INVALID OPTION **")
        myopt = raw_input("Enter Option: ")

    # We make it here and things are good
    if myopt == "1":
        # We want to start the motor
        ToggleRelay(pin, True)
        rtnval = False
    elif myopt == "2":
        # We want to stop the motor
        ToggleRelay(pin, False)
        rtnval = False
    elif myopt in ["q", "Q"]:
        rtnval = True

    # Return
    return rtnval

def Main():
    # Here is where we're going to run our main loop

    # First we'll setup the pin
    Setup(PIN_TO_USE)

    # Now we start our run loop
    # We run while the look returns False
    # once the option functions returns True
    # we exit the loop, cleanup the GPIO, and then exit
    dead = False
    while not dead:
        dead = GetUserOptionAndDoTask(PIN_TO_USE)

    # If we get here, we hit q
    print("\n* EXITING *")
    Cleanup(PIN_TO_USE)

# ============================
if __name__ == "__main__":
    Main()