# Blink the lights on PORTA up and down

from machine import Pin
from time import sleep_ms

PortA = [15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0]

def Init():
    for i in range(0, len(PortA)):
        PortA[i] = Pin(PortA[i], Pin.OUT)

def PortA_Write(X):
    for i in range(0, len(PortA)):
        if(X & (1<<i)):
            PortA[i].value(1)
        else:
            PortA[i].value(0)
            
def PortA_Read():
    X = 0
    for i in range(0, len(PortA)):
        X += (1<<i) * PortA[i].value()
    return(X)

dir = 1
x = 1
Init()
while(1):
    PortA_Write(x)
    if(x & 0x8000):
        dir = -1
    if(x & 1):
        dir = 1
    if(dir == 1):
        x = x << 1
    else:
        x = x >> 1
    sleep_ms(100)