auto-bot

#Import libraries
from gpiozero import Robot, InputDevice, OutputDevice
from time import sleep, time
import random

#Define variables
robo = Robot(left=(8,7), right=(10,9))
trig = OutputDevice(17)
echo = InputDevice(18)
duration = 10
end_time = time() + duration
running = True

#Wait 2 seconds before starting
sleep(2)

#Trigger/Echo pulse time function
def get_pulse_time():
    trig.on()
    sleep(0.00001)
    trig.off()

    while echo.is_active == False:
        pulse_start = time()

    while echo.is_active == True:
        pulse_end = time()

    return pulse_end - pulse_start

#Distance calculation function based on pulse time as input
def calculate_distance(duration):
    speed = 343
    distance = speed * duration / 2
    return distance

#Main loop executes until run time
while running:

    #Calculate pulse time/distance
    duration = get_pulse_time()
    distance = calculate_distance(duration)

    #randomly generate variable time for turning and 0 or 1 for left or right turns
    turn_time = random.uniform(0.1, 0.9)
    left_right = random.randint(0, 1)

    #Drive condition: either forward if no obstacles, or left/right depending on whether 1 or 0
    if distance <= 0.35 and distance != 0:
        robo.backward(0.3)
        sleep(0.2)
        if left_right == 0:
            robo.left(0.6)
        else:
            robo.right(0.6)
        sleep(turn_time)
    else:
        robo.forward(0.3)

    #Running condition: False if over end_time
    if time() > end_time:
        running = False
        robo.stop()

    #print distance to console
    sleep(0.06)
    print(distance)