//在EdgeBoard系统中操作如下命令
//建立PS_MIO12为GPIO
echo 349 > /sys/class/gpio/export

//查看PS_MIO12预置的direction和value
cat /sys/class/gpio/gpio349/direction
cat /sys/class/gpio/gpio349/value

//控制PS_MIO12方向为out，并输出低电平
echo out > /sys/class/gpio/gpio349/direction
echo 0 > /sys/class/gpio/gpio349/value

"""
    Set GPIO output mode, and cycle switching level at interval of 1 s
"""
import os
import sys
import time
import argparse
from pathlib import Path
# args parse
parser = argparse.ArgumentParser(description='manual to gpio param')
parser.add_argument("--port", type=int, default=456, help='')
args = parser.parse_args()
# param init
port = args.port
port_path = "/sys/class/gpio/gpio{0}".format(port)
port_direction_path = "{0}/direction".format(port_path)
port_value_path = "{0}/value".format(port_path)
# enable gpio port
if Path(port_path).is_dir() is False:
    os.system("echo {0} > /sys/class/gpio/export".format(port))
# check enable success
if Path(port_path).is_dir() is False:
    print("Error: Enable Port {0} Faield.".format(port))
    sys.exit()
# gpio set out mode
os.system("echo out > {0}".format(port_direction_path))
while 1:
    print("Port is High ...")
    os.system("echo 0 > {0}".format(port_value_path))  # set low
    time.sleep(1)
    print("Port is Low ...")
    os.system("echo 1 > {0}".format(port_value_path))  # set high
    time.sleep(1)