import machine
import utime

# GPIO setup for LEDs
led_pins = [machine.Pin(i, machine.Pin.OUT) for i in range(0, 10)]  # GPIO 2 to 9
potentiometer = machine.ADC(28)  # Analog pin A0 (GPIO 26)

# Function to clear all LEDs
def clear_leds():
    for led in led_pins:
        led.value(0)

# Function for back-and-forth running lights
def running_lights_back_and_forth():
    direction = 1  # 1 for forward, -1 for reverse
    index = 0  # Current LED index

    while True:
        # Read potentiometer value and map to delay (0.01 to 0.5 seconds)
        pot_value = potentiometer.read_u16()
        delay = 0.05 + (pot_value / 65535.0) * 0.5

        # Turn on the current LED
        led_pins[index].value(1)
        utime.sleep(delay)
        # Turn off the current LED
        led_pins[index].value(0)

        # Update index based on direction
        index += direction

        # Reverse direction if at either end
        if index == len(led_pins) - 1:  # Reached the last LED
            direction = -1  # Change direction to reverse
        elif index == 0:  # Reached the first LED
            direction = 1  # Change direction to forward

try:
    running_lights_back_and_forth()
except KeyboardInterrupt:
    clear_leds()
    print("Program stopped.")