from machine import Pin
from time import sleep

# ============================================================
# ECEN 218 - Digital Logic Laboratory
# Lab 0: Virtual Digital Laboratory and Pico Introduction
#
# The Raspberry Pi Pico is being used as a DIGITAL TEST SYSTEM.
#
# GP2 -> circuit input A
# GP3 -> circuit input B
# GP4 <- circuit output Y
#
# The Pico will automatically generate every possible
# two-input combination and measure the circuit output.
# ============================================================


A = Pin(2, Pin.OUT)
B = Pin(3, Pin.OUT)
Y = Pin(4, Pin.IN)


print()
print("ECEN 218 - Automated Digital Logic Test")
print()

passed = True

print(" A  B | Expected  Measured")
print("------+-------------------")


for a in [0, 1]:
    for b in [0, 1]:

        # Apply the input combination
        A.value(a)
        B.value(b)

        # Wait briefly before measuring
        sleep(0.5)

        # Read the actual circuit output
        measured = Y.value()


        # ====================================================
        # STUDENT TASK
        #
        # The circuit in this starter project is an AND gate.
        #
        # The expression below does NOT yet correctly describe
        # the expected output of the circuit.
        #
        # Replace the expression with one that correctly
        # computes the AND function using variables a and b.
        # ====================================================

        # Useful Python logic operators:
        #   &    AND
        #   |    OR
        #   ^    XOR
        #   not  NOT

        expected = a & b


        # Print the result
        print(
            " %d  %d |    %d         %d"
            % (a, b, expected, measured)
        )


        # Check the circuit
        if measured != expected:
            passed = False


print()
print("--------------------------------")

if passed:
    print("TEST PASSED")
else:
    print("TEST FAILED")

print("--------------------------------")
print()


# Keep the simulator running so the final signals remain
# available for observation.
while True:
    sleep(1)