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


#define PINs according to cabling
dataPIN = 22
latchPIN = 26
clockPIN = 27

#set pins to output PIN objects
dataPIN=Pin(dataPIN, Pin.OUT)
latchPIN=Pin(latchPIN, Pin.OUT)
clockPIN=Pin(clockPIN, Pin.OUT)

#define shift register update function
def shift_update(input,data,clock,latch):
  #put latch down to start data sending
  clock.value(0)
  latch.value(0)
  clock.value(1)
  
  #load data in reverse order
  for i in range(7, -1, -1):
    clock.value(0)
    data.value(int(input[i]))
    clock.value(1)

#put latch up to store data on register
  clock.value(0)
  latch.value(1)
  clock.value(1)

#main program, calling shift register function
bit_string="00001111"


S0 = Pin(9, mode=Pin.OUT)
S1 = Pin(8, mode=Pin.OUT)
S2 = Pin(7, mode=Pin.OUT)
S3 = Pin(6, mode=Pin.OUT)

M0 = Pin(21, mode=Pin.OUT)
M1 = Pin(20, mode=Pin.OUT)
M2 = Pin(19, mode=Pin.OUT)
M3 = Pin(18, mode=Pin.OUT)

M0.off()
M1.off()
M2.off()
M3.off()

S0.off()
S1.off()
S2.off()
S3.off()

muxAdd = [S0, S1, S2, S3]
print(muxAdd[0].value())
print(muxAdd[1].value())
print(muxAdd[2].value())
print(muxAdd[3].value())

while True:
  for i in range (0, 4, 1):
    muxAdd[i].on()
    time.sleep(1)
    muxAdd[i].off()
    time.sleep(1)