Arduino-Makefile/bin/ard-reset-arduino

#!/usr/bin/python3

import serial
import serial.tools.list_ports
import os.path
import argparse
from time import sleep

parser = argparse.ArgumentParser(description='Reset an Arduino')
parser.add_argument('--zero', action='store_true', help='Reset Arduino Zero or similar Native USB to enter bootloader')
parser.add_argument('--caterina', action='store_true', help='Reset a Leonardo, Micro, Robot or LilyPadUSB.')
parser.add_argument('--verbose', action='store_true', help="Watch what's going on on STDERR.")
parser.add_argument('--period', default=0.1, help='Specify the DTR pulse width in seconds.')
parser.add_argument('port', nargs=1, help='Serial device e.g. /dev/ttyACM0')
args = parser.parse_args()


def list_ports(output=False):
    """ Lists serial ports attached

        :returns
            A list of paths to serial ports on system
    """
    ports = serial.tools.list_ports.comports()
    connected = [port[0] for port in ports]
    if output:
        print(connected)

    return connected


def new_port(old, new):
    """ Checks if a new port has attached

        Args:
            old: previous list of ports to check
            new: current list of ports to check
        Returns:
            index of port in 'new' if new port found, otherwise -1
    """
    new_port = -1

    for port in new:
        if port not in old:
            new_port = new.index(port)
            break

    return new_port


if args.zero:
    # number of trys to attempt
    zero_attempts = 20 # ~2 seconds
    initial_ports = list_ports(args.verbose)

    if args.verbose:
        print('Attempting to enter bootloader using 1200 bps open/close on port %s' % args.port[0])

    ser = serial.Serial(args.port[0], 57600)
    ser.close()
    ser.baudrate = 1200

    # do the open/close at 1200 BAUD
    ser.open()
    ser.close()

    if args.verbose:
        print('Done. Waiting for bootloader port to attach...')

    # get new list of ports
    reset_ports = list_ports(args.verbose)

    # wait for new port or port to return
    port_index = new_port(initial_ports, reset_ports)

    # keep checking until new port appears or timeout
    while port_index < 0:
        # count down attempts and leave if expired
        zero_attempts -= 1
        if zero_attempts < 0:
            break
        sleep(0.1)
        # get list of ports after bootloader toggle performed
        reset_ports = list_ports(args.verbose)
        # if a port drops, set initial ports to reset ports so that
        # next attached device will be new port
        if (len(reset_ports) < len(initial_ports)):
            initial_ports = reset_ports
        # check if a new port has attached and return the index if it has
        port_index = new_port(initial_ports, reset_ports)
    # return the new port if detected, otherwise return passed port
    if port_index == -1:
        bootloader_port = args.port[0]
    else:
        bootloader_port = reset_ports[port_index]

    # print so that `tail -1` can be piped for bootloader port
    print(bootloader_port)
elif args.caterina:
    if args.verbose: print('Forcing reset using 1200bps open/close on port %s' % args.port[0])
    ser = serial.Serial(args.port[0], 57600)
    ser.close()

    if pyserial_version < 3:
      ser.setBaudrate (1200)
    else:
      ser.baudrate = 1200

    ser.open()
    ser.setRTS(True)  # RTS line needs to be held high and DTR low
    ser.setDTR(False) # (see Arduino IDE source code)
    ser.close()
    sleep(1)

    while not os.path.exists(args.port[0]):
        if args.verbose: print('Waiting for %s to come back' % args.port[0])
        sleep(1)

    if args.verbose: print('%s has come back after reset' % args.port[0])
else:
    if args.verbose: print('Setting DTR high on %s for %ss' % (args.port[0],args.period))
    ser = serial.Serial(args.port[0], 115200)
    ser.setDTR(False)
    sleep(args.period)
    ser.setDTR(True)
    ser.close()