# Stepper Motor Control

from machine import Pin, Timer
import time

tim = Timer()
Step = 0
Ref = 0

pin1 = Pin(15,Pin.IN,Pin.PULL_UP)
pin2 = Pin(14,Pin.IN,Pin.PULL_UP)

Sa = Pin(6,Pin.OUT)
Sb = Pin(7,Pin.OUT)
Sc = Pin(8,Pin.OUT)
Sd = Pin(9,Pin.OUT)

def Stepper(Step):
    X = Step % 4;
    if(X == 0):
        Sa.value(1)
        Sb.value(0)
        Sc.value(0)
        Sd.value(0)
    if(X == 1):
        Sa.value(0)
        Sb.value(1)
        Sc.value(0)
        Sd.value(0)
    if(X == 2):
        Sa.value(0)
        Sb.value(0)
        Sc.value(1)
        Sd.value(0)
    if(X == 3):
        Sa.value(0)
        Sb.value(0)
        Sc.value(0)
        Sd.value(1)
      
def tick(timer):
    global Step, Ref
    if(Step < Ref):
        Step += 1
    if(Step > Ref):
        Step -= 1
    Stepper(Step)
    
tim.init(freq=100, mode=Timer.PERIODIC, callback=tick)

while (1):
    if(pin1.value() == 0):
        Ref = 0
    if(pin2.value() == 0):
        Ref = 100
    print(Ref, Step, )
    time.sleep(0.1)