import time
from machine import Pin
time.sleep(0.1)  # Wait for USB to become ready

print("Hello, Pi Pico!")

# Pin definitions
led_pin = Pin(2, Pin.OUT)
button_pin = Pin(1, Pin.IN, Pin.PULL_UP)
step_a_minus = Pin(21, Pin.OUT)
step_a_plus = Pin(20, Pin.OUT)
step_b_plus = Pin(19, Pin.OUT)
step_b_minus = Pin(18, Pin.OUT)

# Step sequence for the stepper motor
step_sequence = [
    (1, 0, 1, 0),  # A+ and B+
    (0, 1, 1, 0),  # A- and B+
    (0, 1, 0, 1),  # A- and B-
    (1, 0, 0, 1),  # A+ and B-
]

# Step index to track the current step in the sequence
current_step = 0

# Function to rotate the stepper motor by one step
def stepper_rotate_one_step(clockwise=True):
    global current_step
    # Determine the next step based on direction
    if clockwise:
        current_step = (current_step + 1) % 4
    else:
        current_step = (current_step - 1) % 4

    # Apply the current step
    step = step_sequence[current_step]
    step_a_plus.value(step[0])
    step_a_minus.value(step[1])
    step_b_plus.value(step[2])
    step_b_minus.value(step[3])

# Main loop
while True:
    if button_pin.value() == 0:  # Button pressed
        print("Button pressed!")
        led_pin.value(0)  # Turn ON LED
        # Rotate the motor continuously at 10 Hz while the button is pressed
        start_time = time.ticks_ms()
        while button_pin.value() == 0:  # Stay in this loop while the button is pressed
            stepper_rotate_one_step(clockwise=True)  # Rotate one step clockwise
            time.sleep(0.1)  # Delay for 10 Hz step rate
            # Prevent infinite loop from locking
            if time.ticks_diff(time.ticks_ms(), start_time) > 10000:  # Safety timeout
                break
    else:  # Button not pressed
        print("Button not pressed.")
        led_pin.value(1)  # Turn OFF LED
        # Stop stepper motor
        step_a_plus.value(0)
        step_a_minus.value(0)
        step_b_plus.value(0)
        step_b_minus.value(0)