import pineworkslabs.RPi as GPIO

from random import randint

GPIO $=\text{'}\text{'}$ # don't type this line

GPIO.setmode$($GPIO$.$LE$\_$POTATO$\_$LOOKUP$)$

LEDS $=(25,18,27,23,26,12,16,20,21)$

for led in LEDS:

GPIO.setup$($led$,$ GPIO.OUT$)$

def create$\_$binary$\_$number$()$:

$"""$Generates a list of $8$ bits"""

# Next line is same thing as below but with list comprehension

# num $=[$randint$(0,1)$ for $\_$ in range$(8)]$

num $=[]$

for $\_$ in range$(0,8)$:

num.append$($randint$(0,1))$

return num

def illuminate$($bit$\_$list$)$:

$"""$Illuminates the appropriate LEDS for the provided bit$\_$list"""

for i in range$($len$($bit$\_$list$))$:

if bit$\_$list$[$i$]==1$:

GPIO.output$($LEDS$[$i$],$ GPIO.HIGH$)$

else:

GPIO.output$($LEDS$[$i$],$ GPIO.LOW$)$

def full$\_$adder$($Cin$,$ A$,$ B$)$:

$"""$Implements a full adder to add the arguments"""

# This is HOMEWORK. MUST USE BITWISE OPERATORS LIKE $(^,$ &$,|,$ ~$)$ NOT THE WORDS FOR THEM

return S$,$ Cout

def calculate$($num$1,$ num$2)$:

$"""$Takes in two bit lists and adds them. Returns the sum as a bit list"""

Cout $=0$

Sum $=[]$

n $=$ len$($num$1)-1$ # get the position of the rightmost bit

while n $>=0$:

A $=$ num$1[$n$]$

B $=$ num$2[$n$]$

Cin $=$ Cout

S$,$ Cout $=$ full$\_$adder$($Cin$,$ A$,$ B$)$

sum.insert$(0,$ S$)$

n $-=1$

sum.insert$(0,$ Cout$)$

return sum

################ MAIN PROGRAM ##########################

num$1=$ create$\_$binary$\_$number$()$

print$("",$ num$1)$

num$2=$ create$\_$binary$\_$number$()$

print$("+",$ num$2)$

sum $=$ calculate$($num$1,$ num$2)$

print$("=",$ sum$)$

illuminate$($sum$)$

input$("$Press ENTER key to terminate"$)$

GPIO.cleanup$()$