from machine import Pin
from time import sleep

# ------------------------------------------------------------
# ECEN 218 - Digital Logic Laboratory
# Lab 0: Virtual Digital Laboratory and Pico Introduction
#
# Raspberry Pi Pico pin assignments:
#
#   GP2 -> Logic input A
#   GP3 -> Logic input B
#   GP4 <- Logic output Y
#
# The Pico will:
#   1. Generate all possible combinations of A and B
#   2. Read the resulting value of Y
#   3. Print the measured truth table
#   4. Compare the measured value to the expected value
#   5. Report whether the circuit passes the test
# ------------------------------------------------------------


# Configure Pico GPIO pins
A = Pin(2, Pin.OUT)
B = Pin(3, Pin.OUT)
Y = Pin(4, Pin.IN)


print()
print("----------------------------------------")
print("ECEN 218 - Lab 0")
print("Digital Logic Automated Test")
print("----------------------------------------")
print()

passed = True

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

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

        # Apply digital inputs to the circuit
        A.value(a)
        B.value(b)

        # Allow the circuit to settle
        sleep(0.5)

        # Measure the circuit output
        measured = Y.value()

        # ----------------------------------------------------
        # STUDENT TASK:
        #
        # Complete the expression below so that "expected"
        # contains the correct output of the AND function.
        #
        # Replace the 0 with the appropriate Python
        # expression.
        # ----------------------------------------------------

        expected = a & b

        # Display one row of the truth table
        print(
            " %d  %d |    %d         %d"
            % (a, b, expected, measured)
        )

        # Compare expected and measured results
        if measured != expected:
            passed = False


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

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

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

# Hold the final input values so the simulation remains active
while True:
    sleep(1)