Piface/Raspberry Pi Pelican crossing light control.

crossing_lights.py

import piface.pfio
import time
import sys

class crossinglight:
        """ A (UK) Crossing traffic light """

        def __init__(self, red_pin, amber_pin, green_pin, red_man_pin, green_man_pin, beeper, button):
                self.red_pin = red_pin
                self.amber_pin = amber_pin
                self.green_pin = green_pin
                self.red_man_pin = red_man_pin
                self.green_man_pin = green_man_pin
                self.beeper = beeper
                self.button = button

                self.status = 'green'
                piface.pfio.digital_write(self.green_pin, 1)
                piface.pfio.digital_write(self.red_man_pin, 1)

        def beep(self):
                for cnt in range(1, 10):
                        piface.pfio.digital_write(self.beeper, 1)
                        time.sleep(1)

                        piface.pfio.digital_write(self.beeper, 0)
                        time.sleep(1)

        def wait_for_button(self):
                pressed = False;
                while pressed == False:
                        if piface.pfio.digital_read(self.button) == 1:
                                pressed = True;

        def toggle(self):
                cnt = 0;

                if self.status == 'red':
                        piface.pfio.digital_write(self.red_pin, 0)

                        # Transitioning from red to green, blink amber light and green man
                        for cnt in range(1, 5):
                                piface.pfio.digital_write(self.amber_pin, 1)
                                piface.pfio.digital_write(self.green_man_pin, 1)
                                time.sleep(1)

                                piface.pfio.digital_write(self.amber_pin, 0)
                                piface.pfio.digital_write(self.green_man_pin, 0)

                                time.sleep(1)

                        piface.pfio.digital_write(self.amber_pin, 0)
                        piface.pfio.digital_write(self.red_pin, 0)
                        piface.pfio.digital_write(self.green_pin, 1)

                        piface.pfio.digital_write(self.green_man_pin, 0)
                        piface.pfio.digital_write(self.red_man_pin, 1)

                        self.status = 'green'
                else:
                        piface.pfio.digital_write(self.green_pin, 0)
                        piface.pfio.digital_write(self.amber_pin, 1)
                        time.sleep(2)

                        piface.pfio.digital_write(self.amber_pin, 0)
                        piface.pfio.digital_write(self.red_pin, 1)

                        piface.pfio.digital_write(self.green_man_pin, 1)
                        piface.pfio.digital_write(self.red_man_pin, 0)

                        self.status = 'red'


def main(argv):
        piface.pfio.init()

        # initialise our light
        light = crossinglight(0,1,2, 3,4, 5, 0)

        # Loop, waiting for button press (probably could be done better with interrupts)
        while True:
                light.wait_for_button();

                light.toggle()
                light.beep()
                light.toggle()

if __name__ == "__main__":
    sys.exit(main(sys.argv))