from machine import Pin, I2C
import time
import ssd1306

# ========== Pins ==========
IN1 = Pin(2, Pin.OUT)
IN2 = Pin(3, Pin.OUT)
IN3 = Pin(4, Pin.OUT)
IN4 = Pin(5, Pin.OUT)

LIMIT = Pin(6, Pin.IN, Pin.PULL_UP)  # Limit switch (active LOW)

# ========== OLED ==========
i2c = I2C(0, sda=Pin(0), scl=Pin(1), freq=400000)
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# ========== Stepper sequence for 28BYJ-48 ==========
seq = [
    [1,0,0,1],
    [1,0,0,0],
    [1,1,0,0],
    [0,1,0,0],
    [0,1,1,0],
    [0,0,1,0],
    [0,0,1,1],
    [0,0,0,1]
]

# Global position counter
position = 0
STEP_DELAY = 0.003  # Adjust speed (increase for slower movement)

# ========== Functions ==========
def step_motor(steps, direction=1):
    global position
    for _ in range(steps):
        if direction == 1:
            sequence = seq
        else:
            sequence = reversed(seq)
        for s in sequence:
            IN1.value(s[0])
            IN2.value(s[1])
            IN3.value(s[2])
            IN4.value(s[3])
            time.sleep(STEP_DELAY)
        position += direction
        oled.fill(0)
        oled.text("Eye Scan Position", 0, 0)
        oled.text("Step: {}".format(position), 0, 20)
        oled.show()

def home():
    global position
    oled.fill(0)
    oled.text("Homing...", 0, 0)
    oled.show()
    while LIMIT.value() == 1:  # not pressed
        step_motor(1, direction=-1)
    oled.fill(0)
    oled.text("Homed!", 0, 0)
    oled.show()
    time.sleep(1)
    position = 0

# ========== Main ==========
home()
while True:
    # Move step-by-step forward
    step_motor(50, direction=1)
    time.sleep(0.5)