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"""Tool used to reset a Arduino Leonardo board."""
from os import O_NDELAY, O_NOCTTY, O_RDWR, open as os_open, close as os_close
import sys
from termios import (
B1200,
TCSANOW,
TIOCM_DTR,
TIOCM_RTS,
TIOCMBIC,
TIOCMBIS,
tcgetattr,
tcsetattr
)
from fcntl import ioctl
from argparse import ArgumentParser
from dataclasses import dataclass
from pathlib import Path
from struct import pack
from time import sleep
@dataclass
class ParsedArguments:
"""Parsed command-line arguments."""
serial_port: Path
class TTYAttributes:
"""TTY attributes."""
def __init__(self, tty_fd: int):
"""Initializes the TTY attributes."""
self.__tty_fd = tty_fd
self.__attrs = tcgetattr(tty_fd)
@property
def ispeed(self):
"""The ispeed."""
return self.__attrs[4]
@ispeed.setter
def ispeed(self, ispeed: int):
self.__attrs[4] = ispeed
@property
def ospeed(self):
"""The ospeed."""
return self.__attrs[5]
@ospeed.setter
def ospeed(self, ospeed: int):
self.__attrs[5] = ospeed
def set(self):
"""Sets the TTY attributes."""
tcsetattr(self.__tty_fd, TCSANOW, self.__attrs)
RESET_BAUD_RATE = B1200
DESCRIPTION = "Tool used to reset a Arduino Leonardo board."
def main():
"""Main."""
parser = ArgumentParser(allow_abbrev=False, description=DESCRIPTION)
parser.add_argument(
"serial_port",
type=Path,
help="The serial port for a Arduino Leonardo board"
)
arguments = parser.parse_args(namespace=ParsedArguments)
is_serial_port_char_device = arguments.serial_port.is_char_device()
# Verify that the serial port exists
if not arguments.serial_port.is_file() and not is_serial_port_char_device:
print("Error: The serial port file doesn't exist")
sys.exit(1)
# Verify that the serial port is a character device
if not is_serial_port_char_device:
print("Error: The serial port file is not a character device")
sys.exit(1)
serial_port_fd = os_open(
str(arguments.serial_port),
O_RDWR | O_NOCTTY | O_NDELAY
)
tty_attributes = TTYAttributes(serial_port_fd)
tty_attributes.ispeed = RESET_BAUD_RATE
tty_attributes.ospeed = RESET_BAUD_RATE
tty_attributes.set()
ioctl(serial_port_fd, TIOCMBIS, pack("I", TIOCM_RTS))
ioctl(serial_port_fd, TIOCMBIC, pack("I", TIOCM_DTR))
os_close(serial_port_fd)
sleep(1.98)
if __name__ == "__main__":
main()
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