Reading robot car sensory data with Python

Although we have covered this before, it's a good idea to familiarize (or re-familiarize) ourselves with the programming of the HC-SR04:

1. Open up Thonny from Application Menu | Programming | Thonny Python IDE.
2. Click New to create a new file.
3. Type the following:

from gpiozero import DistanceSensor
from time import sleep

distance_sensor = DistanceSensor(echo=18, trigger=17)

while True:
    print('Distance: ', distance_sensor.distance*100)
    sleep(1)

4. Save the file as distance-sensor-test.py.
5. Run the code.
6. Place your hand in front of the distance sensor. You should see the following in the shell (depending on how far your hand is from the distance sensor):

Distance: 5.05452024001

7. As you move your hand closer to, or farther away from, the distance sensor, the value will change. This code is pretty self explanatory. The distance_sensor...