$4\mathrm{.}1$ Understanding Code

All code should be pseudo code and submitted before the lab. Code should be written and

submitted as a $.$txt file. Grades will be given to the structure of code, rather than if it is

functioning. In other words, it is more important that you figure out how the code should be

written, rather than the position of every colon or bracket.

$1.$ Prepare the code that will determine if the limit switch is pressed or not. The switch

is normally open and connected to pin $20$

$2.$ The code provided for this lab introduces the use of object$-$oriented programming

with Python. This essentially means that when you run the code, it creates objects $($in

Python they are called classes$)$ and calls methods from those classes to perform the

desired actions. Using the provided code as your guide, go back and create a Motor

object that uses the code you wrote in the first lab. More information about the OOP

can be found in the lectures or here.

$3.$ The DistanceSensor.py library provides a simple implementation of the ultrasonic

sensor$.$ Rather than use that library, look online and see if you can find a way to

calculate the distance without using the DistanceSensor.py library. Hint: you will

need to use both the ECHO and TRIGGER pin, as well as know the speed of sound.

$4\mathrm{.}2$ Understanding Circuitry

$1.$ The LCD is controlled by I$2$C$,$ but does not need to be$.$ Using the component data

sheet, create a circuit diagram that uses GPIO pins rather than I$2$C$.$

$4\mathrm{.}3$ Understanding Mechanical Systems

$1.$ If your ultrasonic sensor measures a time of $0\mathrm{.}03$ microseconds, how far away is the

object?

$2.$ The rotary encoder has an output shaft that is $4\mathrm{.}5$mm in diameter and is directly

connected to the wheel which has a diameter of $6$cm$.$ If the rotary encoder has $30$

positions per revolution, how far does the robot travel per increment?