import machine
import utime

# Define pin numbers
trig_pin = 2  # Trig pin of ultrasonic sensor
echo_pin = 3  # Echo pin of ultrasonic sensor
button_pin = 4  # Pin for the push button
step_pin = 5  # Step pin for the stepper motor driver
dir_pin = 6  # Direction pin for the stepper motor driver
enable_pin = 7  # Enable pin for the stepper motor driver

# Setup ultrasonic sensor
trig = machine.Pin(trig_pin, machine.Pin.OUT)
echo = machine.Pin(echo_pin, machine.Pin.IN)

# Setup push button
button = machine.Pin(button_pin, machine.Pin.IN, machine.Pin.PULL_DOWN)
button_pressed = False
last_button_state = 0

# Setup stepper motor driver
step = machine.Pin(step_pin, machine.Pin.OUT)
dir = machine.Pin(dir_pin, machine.Pin.OUT)
enable = machine.Pin(enable_pin, machine.Pin.OUT)

# Function to measure distance using ultrasonic sensor
def measure_distance():
    trig.value(1)
    utime.sleep_us(10)
    trig.value(0)
    
    while echo.value() == 0:
        pulse_start = utime.ticks_us()
    while echo.value() == 1:
        pulse_end = utime.ticks_us()
    
    pulse_duration = pulse_end - pulse_start
    distance = (pulse_duration * 0.0343) / 2  # Speed of sound is approximately 343 meters/second
    
    return distance

# Function to control stepper motor steps and direction
def control_stepper(distance):
    # Map distance to the number of steps
    steps = int((distance / max_distance) * max_steps)
    
    # Set stepper motor direction based on button press
    dir.value(0 if not button_pressed else 1)
    
    # Enable the stepper motor driver
    enable.value(0)
    
    # Generate steps
    for _ in range(steps):
        step.value(1)
        utime.sleep_us(500)  # Adjust delay as needed
        step.value(0)
        utime.sleep_us(500)  # Adjust delay as needed
    
    # Disable the stepper motor driver
    enable.value(1)

# Main loop
max_distance = 50  # Adjust this value based on your specific requirements
max_steps = 200  # Adjust this value based on your stepper motor specifications
direction_change_threshold = 0.5  # Time delay between button presses to avoid multiple changes

last_button_press_time = utime.ticks_ms()

while True:
    # Measure distance
    distance = measure_distance()
    
    # Check button press
    current_button_state = button.value()
    if current_button_state == 1 and last_button_state == 0:
        current_time = utime.ticks_ms()
        if utime.ticks_diff(current_time, last_button_press_time) > direction_change_threshold:
            button_pressed = not button_pressed
            last_button_press_time = current_time
    
    # Update last button state
    last_button_state = current_button_state
    
    # Control stepper motor based on distance and button press
    control_stepper(distance)
    
    # Print information
    print("Distance: {:.2f} cm".format(distance))
    print("Stepper Motor Steps: {}".format(int((distance / max_distance) * max_steps)))
    print("Direction: {}".format("Forward" if not button_pressed else "Reverse"))
    
    # Add a small delay to avoid excessive printing
    utime.sleep(0.1)