add circuitpython code

1 files changed, 766 insertions, 0 deletions

diff --git a/circuitpython/tools/pyboard.py b/circuitpython/tools/pyboard.py
new file mode 100755
index 0000000..a43a4d0
--- /dev/null
+++ b/circuitpython/tools/pyboard.py
@@ -0,0 +1,766 @@
+#!/usr/bin/env python3
+
+# SPDX-FileCopyrightText: Copyright (c) 2014-2021 Damien P. George
+# SPDX-FileCopyrightText: Copyright (c) 2017 Paul Sokolovsky
+# SPDX-FileCopyrightText: 2014 MicroPython & CircuitPython contributors (https://github.com/adafruit/circuitpython/graphs/contributors)
+#
+# SPDX-License-Identifier: MIT
+
+"""
+pyboard interface
+
+This module provides the Pyboard class, used to communicate with and
+control a MicroPython device over a communication channel. Both real
+boards and emulated devices (e.g. running in QEMU) are supported.
+Various communication channels are supported, including a serial
+connection, telnet-style network connection, external process
+connection.
+
+Example usage:
+
+    import pyboard
+    pyb = pyboard.Pyboard('/dev/ttyACM0')
+
+Or:
+
+    pyb = pyboard.Pyboard('192.168.1.1')
+
+Then:
+
+    pyb.enter_raw_repl()
+    pyb.exec('import pyb')
+    pyb.exec('pyb.LED(1).on()')
+    pyb.exit_raw_repl()
+
+Note: if using Python2 then pyb.exec must be written as pyb.exec_.
+To run a script from the local machine on the board and print out the results:
+
+    import pyboard
+    pyboard.execfile('test.py', device='/dev/ttyACM0')
+
+This script can also be run directly.  To execute a local script, use:
+
+    ./pyboard.py test.py
+
+Or:
+
+    python pyboard.py test.py
+
+"""
+
+import sys
+import time
+import os
+import ast
+
+try:
+    stdout = sys.stdout.buffer
+except AttributeError:
+    # Python2 doesn't have buffer attr
+    stdout = sys.stdout
+
+
+def stdout_write_bytes(b):
+    b = b.replace(b"\x04", b"")
+    stdout.write(b)
+    stdout.flush()
+
+
+class PyboardError(Exception):
+    pass
+
+
+class TelnetToSerial:
+    def __init__(self, ip, user, password, read_timeout=None):
+        self.tn = None
+        import telnetlib
+
+        self.tn = telnetlib.Telnet(ip, timeout=15)
+        self.read_timeout = read_timeout
+        if b"Login as:" in self.tn.read_until(b"Login as:", timeout=read_timeout):
+            self.tn.write(bytes(user, "ascii") + b"\r\n")
+
+            if b"Password:" in self.tn.read_until(b"Password:", timeout=read_timeout):
+                # needed because of internal implementation details of the telnet server
+                time.sleep(0.2)
+                self.tn.write(bytes(password, "ascii") + b"\r\n")
+
+                if b"for more information." in self.tn.read_until(
+                    b'Type "help()" for more information.', timeout=read_timeout
+                ):
+                    # login successful
+                    from collections import deque
+
+                    self.fifo = deque()
+                    return
+
+        raise PyboardError("Failed to establish a telnet connection with the board")
+
+    def __del__(self):
+        self.close()
+
+    def close(self):
+        if self.tn:
+            self.tn.close()
+
+    def read(self, size=1):
+        while len(self.fifo) < size:
+            timeout_count = 0
+            data = self.tn.read_eager()
+            if len(data):
+                self.fifo.extend(data)
+                timeout_count = 0
+            else:
+                time.sleep(0.25)
+                if self.read_timeout is not None and timeout_count > 4 * self.read_timeout:
+                    break
+                timeout_count += 1
+
+        data = b""
+        while len(data) < size and len(self.fifo) > 0:
+            data += bytes([self.fifo.popleft()])
+        return data
+
+    def write(self, data):
+        self.tn.write(data)
+        return len(data)
+
+    def inWaiting(self):
+        n_waiting = len(self.fifo)
+        if not n_waiting:
+            data = self.tn.read_eager()
+            self.fifo.extend(data)
+            return len(data)
+        else:
+            return n_waiting
+
+
+class ProcessToSerial:
+    "Execute a process and emulate serial connection using its stdin/stdout."
+
+    def __init__(self, cmd):
+        import subprocess
+
+        self.subp = subprocess.Popen(
+            cmd,
+            bufsize=0,
+            shell=True,
+            preexec_fn=os.setsid,
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+        )
+
+        # Initially was implemented with selectors, but that adds Python3
+        # dependency. However, there can be race conditions communicating
+        # with a particular child process (like QEMU), and selectors may
+        # still work better in that case, so left inplace for now.
+        #
+        # import selectors
+        # self.sel = selectors.DefaultSelector()
+        # self.sel.register(self.subp.stdout, selectors.EVENT_READ)
+
+        import select
+
+        self.poll = select.poll()
+        self.poll.register(self.subp.stdout.fileno())
+
+    def close(self):
+        import signal
+
+        os.killpg(os.getpgid(self.subp.pid), signal.SIGTERM)
+
+    def read(self, size=1):
+        data = b""
+        while len(data) < size:
+            data += self.subp.stdout.read(size - len(data))
+        return data
+
+    def write(self, data):
+        self.subp.stdin.write(data)
+        return len(data)
+
+    def inWaiting(self):
+        # res = self.sel.select(0)
+        res = self.poll.poll(0)
+        if res:
+            return 1
+        return 0
+
+
+class ProcessPtyToTerminal:
+    """Execute a process which creates a PTY and prints secondary PTY as
+    first line of its output, and emulate serial connection using
+    this PTY."""
+
+    def __init__(self, cmd):
+        import subprocess
+        import re
+        import serial
+
+        self.subp = subprocess.Popen(
+            cmd.split(),
+            bufsize=0,
+            shell=False,
+            preexec_fn=os.setsid,
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        pty_line = self.subp.stderr.readline().decode("utf-8")
+        m = re.search(r"/dev/pts/[0-9]+", pty_line)
+        if not m:
+            print("Error: unable to find PTY device in startup line:", pty_line)
+            self.close()
+            sys.exit(1)
+        pty = m.group()
+        # rtscts, dsrdtr params are to workaround pyserial bug:
+        # http://stackoverflow.com/questions/34831131/pyserial-does-not-play-well-with-virtual-port
+        self.ser = serial.Serial(pty, interCharTimeout=1, rtscts=True, dsrdtr=True)
+
+    def close(self):
+        import signal
+
+        os.killpg(os.getpgid(self.subp.pid), signal.SIGTERM)
+
+    def read(self, size=1):
+        return self.ser.read(size)
+
+    def write(self, data):
+        return self.ser.write(data)
+
+    def inWaiting(self):
+        return self.ser.inWaiting()
+
+
+class Pyboard:
+    def __init__(
+        self, device, baudrate=115200, user="micro", password="python", wait=0, exclusive=True
+    ):
+        self.in_raw_repl = False
+        self.use_raw_paste = True
+        if device.startswith("exec:"):
+            self.serial = ProcessToSerial(device[len("exec:") :])
+        elif device.startswith("execpty:"):
+            self.serial = ProcessPtyToTerminal(device[len("qemupty:") :])
+        elif device and device[0].isdigit() and device[-1].isdigit() and device.count(".") == 3:
+            # device looks like an IP address
+            self.serial = TelnetToSerial(device, user, password, read_timeout=10)
+        else:
+            import serial
+
+            # Set options, and exclusive if pyserial supports it
+            serial_kwargs = {"baudrate": baudrate, "interCharTimeout": 1}
+            if serial.__version__ >= "3.3":
+                serial_kwargs["exclusive"] = exclusive
+
+            delayed = False
+            for attempt in range(wait + 1):
+                try:
+                    self.serial = serial.Serial(device, **serial_kwargs)
+                    break
+                except (OSError, IOError):  # Py2 and Py3 have different errors
+                    if wait == 0:
+                        continue
+                    if attempt == 0:
+                        sys.stdout.write("Waiting {} seconds for pyboard ".format(wait))
+                        delayed = True
+                time.sleep(1)
+                sys.stdout.write(".")
+                sys.stdout.flush()
+            else:
+                if delayed:
+                    print("")
+                raise PyboardError("failed to access " + device)
+            if delayed:
+                print("")
+
+    def close(self):
+        self.serial.close()
+
+    def read_until(self, min_num_bytes, ending, timeout=10, data_consumer=None):
+        # if data_consumer is used then data is not accumulated and the ending must be 1 byte long
+        assert data_consumer is None or len(ending) == 1
+
+        data = self.serial.read(min_num_bytes)
+        if data_consumer:
+            data_consumer(data)
+        timeout_count = 0
+        while True:
+            if data.endswith(ending):
+                break
+            elif self.serial.inWaiting() > 0:
+                new_data = self.serial.read(1)
+                if data_consumer:
+                    data_consumer(new_data)
+                    data = new_data
+                else:
+                    data = data + new_data
+                timeout_count = 0
+            else:
+                timeout_count += 1
+                if timeout is not None and timeout_count >= 100 * timeout:
+                    break
+                time.sleep(0.01)
+        return data
+
+    def enter_raw_repl(self, soft_reset=True):
+        self.serial.write(b"\r\x03\x03")  # ctrl-C twice: interrupt any running program
+
+        # flush input (without relying on serial.flushInput())
+        n = self.serial.inWaiting()
+        while n > 0:
+            self.serial.read(n)
+            n = self.serial.inWaiting()
+
+        self.serial.write(b"\r\x01")  # ctrl-A: enter raw REPL
+
+        if soft_reset:
+            data = self.read_until(1, b"raw REPL; CTRL-B to exit\r\n>")
+            if not data.endswith(b"raw REPL; CTRL-B to exit\r\n>"):
+                print(data)
+                raise PyboardError("could not enter raw repl")
+
+            self.serial.write(b"\x04")  # ctrl-D: soft reset
+
+            # Waiting for "soft reboot" independently to "raw REPL" (done below)
+            # allows boot.py to print, which will show up after "soft reboot"
+            # and before "raw REPL".
+            data = self.read_until(1, b"soft reboot\r\n")
+            if not data.endswith(b"soft reboot\r\n"):
+                print(data)
+                raise PyboardError("could not enter raw repl")
+
+        data = self.read_until(1, b"raw REPL; CTRL-B to exit\r\n")
+        if not data.endswith(b"raw REPL; CTRL-B to exit\r\n"):
+            print(data)
+            raise PyboardError("could not enter raw repl")
+
+        self.in_raw_repl = True
+
+    def exit_raw_repl(self):
+        self.serial.write(b"\r\x02")  # ctrl-B: enter friendly REPL
+        self.in_raw_repl = False
+
+    def follow(self, timeout, data_consumer=None):
+        # wait for normal output
+        data = self.read_until(1, b"\x04", timeout=timeout, data_consumer=data_consumer)
+        if not data.endswith(b"\x04"):
+            raise PyboardError("timeout waiting for first EOF reception")
+        data = data[:-1]
+
+        # wait for error output
+        data_err = self.read_until(1, b"\x04", timeout=timeout)
+        if not data_err.endswith(b"\x04"):
+            raise PyboardError("timeout waiting for second EOF reception")
+        data_err = data_err[:-1]
+
+        # return normal and error output
+        return data, data_err
+
+    def raw_paste_write(self, command_bytes):
+        # Read initial header, with window size.
+        data = self.serial.read(2)
+        window_size = data[0] | data[1] << 8
+        window_remain = window_size
+
+        # Write out the command_bytes data.
+        i = 0
+        while i < len(command_bytes):
+            while window_remain == 0 or self.serial.inWaiting():
+                data = self.serial.read(1)
+                if data == b"\x01":
+                    # Device indicated that a new window of data can be sent.
+                    window_remain += window_size
+                elif data == b"\x04":
+                    # Device indicated abrupt end.  Acknowledge it and finish.
+                    self.serial.write(b"\x04")
+                    return
+                else:
+                    # Unexpected data from device.
+                    raise PyboardError("unexpected read during raw paste: {}".format(data))
+            # Send out as much data as possible that fits within the allowed window.
+            b = command_bytes[i : min(i + window_remain, len(command_bytes))]
+            self.serial.write(b)
+            window_remain -= len(b)
+            i += len(b)
+
+        # Indicate end of data.
+        self.serial.write(b"\x04")
+
+        # Wait for device to acknowledge end of data.
+        data = self.read_until(1, b"\x04")
+        if not data.endswith(b"\x04"):
+            raise PyboardError("could not complete raw paste: {}".format(data))
+
+    def exec_raw_no_follow(self, command):
+        if isinstance(command, bytes):
+            command_bytes = command
+        else:
+            command_bytes = bytes(command, encoding="utf8")
+
+        # check we have a prompt
+        data = self.read_until(1, b">")
+        if not data.endswith(b">"):
+            raise PyboardError("could not enter raw repl")
+
+        if self.use_raw_paste:
+            # Try to enter raw-paste mode.
+            self.serial.write(b"\x05A\x01")
+            data = self.serial.read(2)
+            if data == b"R\x00":
+                # Device understood raw-paste command but doesn't support it.
+                pass
+            elif data == b"R\x01":
+                # Device supports raw-paste mode, write out the command using this mode.
+                return self.raw_paste_write(command_bytes)
+            else:
+                # Device doesn't support raw-paste, fall back to normal raw REPL.
+                data = self.read_until(1, b"w REPL; CTRL-B to exit\r\n>")
+                if not data.endswith(b"w REPL; CTRL-B to exit\r\n>"):
+                    print(data)
+                    raise PyboardError("could not enter raw repl")
+            # Don't try to use raw-paste mode again for this connection.
+            self.use_raw_paste = False
+
+        # Write command using standard raw REPL, 256 bytes every 10ms.
+        for i in range(0, len(command_bytes), 256):
+            self.serial.write(command_bytes[i : min(i + 256, len(command_bytes))])
+            time.sleep(0.01)
+        self.serial.write(b"\x04")
+
+        # check if we could exec command
+        data = self.serial.read(2)
+        if data != b"OK":
+            raise PyboardError("could not exec command (response: %r)" % data)
+
+    def exec_raw(self, command, timeout=10, data_consumer=None):
+        self.exec_raw_no_follow(command)
+        return self.follow(timeout, data_consumer)
+
+    def eval(self, expression):
+        ret = self.exec_("print({})".format(expression))
+        ret = ret.strip()
+        return ret
+
+    def exec_(self, command, data_consumer=None):
+        ret, ret_err = self.exec_raw(command, data_consumer=data_consumer)
+        if ret_err:
+            raise PyboardError("exception", ret, ret_err)
+        return ret
+
+    def execfile(self, filename):
+        with open(filename, "rb") as f:
+            pyfile = f.read()
+        return self.exec_(pyfile)
+
+    def get_time(self):
+        t = str(self.eval("pyb.RTC().datetime()"), encoding="utf8")[1:-1].split(", ")
+        return int(t[4]) * 3600 + int(t[5]) * 60 + int(t[6])
+
+    def fs_ls(self, src):
+        cmd = (
+            "import uos\nfor f in uos.ilistdir(%s):\n"
+            " print('{:12} {}{}'.format(f[3]if len(f)>3 else 0,f[0],'/'if f[1]&0x4000 else ''))"
+            % (("'%s'" % src) if src else "")
+        )
+        self.exec_(cmd, data_consumer=stdout_write_bytes)
+
+    def fs_cat(self, src, chunk_size=256):
+        cmd = (
+            "with open('%s') as f:\n while 1:\n"
+            "  b=f.read(%u)\n  if not b:break\n  print(b,end='')" % (src, chunk_size)
+        )
+        self.exec_(cmd, data_consumer=stdout_write_bytes)
+
+    def fs_get(self, src, dest, chunk_size=256):
+        self.exec_("f=open('%s','rb')\nr=f.read" % src)
+        with open(dest, "wb") as f:
+            while True:
+                data = bytearray()
+                self.exec_("print(r(%u))" % chunk_size, data_consumer=lambda d: data.extend(d))
+                assert data.endswith(b"\r\n\x04")
+                try:
+                    data = ast.literal_eval(str(data[:-3], "ascii"))
+                    if not isinstance(data, bytes):
+                        raise ValueError("Not bytes")
+                except (UnicodeError, ValueError) as e:
+                    raise PyboardError("fs_get: Could not interpret received data: %s" % str(e))
+                if not data:
+                    break
+                f.write(data)
+        self.exec_("f.close()")
+
+    def fs_put(self, src, dest, chunk_size=256):
+        self.exec_("f=open('%s','wb')\nw=f.write" % dest)
+        with open(src, "rb") as f:
+            while True:
+                data = f.read(chunk_size)
+                if not data:
+                    break
+                if sys.version_info < (3,):
+                    self.exec_("w(b" + repr(data) + ")")
+                else:
+                    self.exec_("w(" + repr(data) + ")")
+        self.exec_("f.close()")
+
+    def fs_mkdir(self, dir):
+        self.exec_("import uos\nuos.mkdir('%s')" % dir)
+
+    def fs_rmdir(self, dir):
+        self.exec_("import uos\nuos.rmdir('%s')" % dir)
+
+    def fs_rm(self, src):
+        self.exec_("import uos\nuos.remove('%s')" % src)
+
+
+# in Python2 exec is a keyword so one must use "exec_"
+# but for Python3 we want to provide the nicer version "exec"
+setattr(Pyboard, "exec", Pyboard.exec_)
+
+
+def execfile(filename, device="/dev/ttyACM0", baudrate=115200, user="micro", password="python"):
+    pyb = Pyboard(device, baudrate, user, password)
+    pyb.enter_raw_repl()
+    output = pyb.execfile(filename)
+    stdout_write_bytes(output)
+    pyb.exit_raw_repl()
+    pyb.close()
+
+
+def filesystem_command(pyb, args):
+    def fname_remote(src):
+        if src.startswith(":"):
+            src = src[1:]
+        return src
+
+    def fname_cp_dest(src, dest):
+        src = src.rsplit("/", 1)[-1]
+        if dest is None or dest == "":
+            dest = src
+        elif dest == ".":
+            dest = "./" + src
+        elif dest.endswith("/"):
+            dest += src
+        return dest
+
+    cmd = args[0]
+    args = args[1:]
+    try:
+        if cmd == "cp":
+            srcs = args[:-1]
+            dest = args[-1]
+            if srcs[0].startswith("./") or dest.startswith(":"):
+                op = pyb.fs_put
+                fmt = "cp %s :%s"
+                dest = fname_remote(dest)
+            else:
+                op = pyb.fs_get
+                fmt = "cp :%s %s"
+            for src in srcs:
+                src = fname_remote(src)
+                dest2 = fname_cp_dest(src, dest)
+                print(fmt % (src, dest2))
+                op(src, dest2)
+        else:
+            op = {
+                "ls": pyb.fs_ls,
+                "cat": pyb.fs_cat,
+                "mkdir": pyb.fs_mkdir,
+                "rmdir": pyb.fs_rmdir,
+                "rm": pyb.fs_rm,
+            }[cmd]
+            if cmd == "ls" and not args:
+                args = [""]
+            for src in args:
+                src = fname_remote(src)
+                print("%s :%s" % (cmd, src))
+                op(src)
+    except PyboardError as er:
+        print(str(er.args[2], "ascii"))
+        pyb.exit_raw_repl()
+        pyb.close()
+        sys.exit(1)
+
+
+_injected_import_hook_code = """\
+import uos, uio
+class _FS:
+  class File(uio.IOBase):
+    def __init__(self):
+      self.off = 0
+    def ioctl(self, request, arg):
+      return 0
+    def readinto(self, buf):
+      buf[:] = memoryview(_injected_buf)[self.off:self.off + len(buf)]
+      self.off += len(buf)
+      return len(buf)
+  mount = umount = chdir = lambda *args: None
+  def stat(self, path):
+    if path == '_injected.mpy':
+      return tuple(0 for _ in range(10))
+    else:
+      raise OSError(-2) # ENOENT
+  def open(self, path, mode):
+    return self.File()
+uos.mount(_FS(), '/_')
+uos.chdir('/_')
+from _injected import *
+uos.umount('/_')
+del _injected_buf, _FS
+"""
+
+
+def main():
+    import argparse
+
+    cmd_parser = argparse.ArgumentParser(description="Run scripts on the pyboard.")
+    cmd_parser.add_argument(
+        "-d",
+        "--device",
+        default=os.environ.get("PYBOARD_DEVICE", "/dev/ttyACM0"),
+        help="the serial device or the IP address of the pyboard",
+    )
+    cmd_parser.add_argument(
+        "-b",
+        "--baudrate",
+        default=os.environ.get("PYBOARD_BAUDRATE", "115200"),
+        help="the baud rate of the serial device",
+    )
+    cmd_parser.add_argument("-u", "--user", default="micro", help="the telnet login username")
+    cmd_parser.add_argument("-p", "--password", default="python", help="the telnet login password")
+    cmd_parser.add_argument("-c", "--command", help="program passed in as string")
+    cmd_parser.add_argument(
+        "-w",
+        "--wait",
+        default=0,
+        type=int,
+        help="seconds to wait for USB connected board to become available",
+    )
+    group = cmd_parser.add_mutually_exclusive_group()
+    group.add_argument(
+        "--soft-reset",
+        default=True,
+        action="store_true",
+        help="Whether to perform a soft reset when connecting to the board [default]",
+    )
+    group.add_argument(
+        "--no-soft-reset",
+        action="store_false",
+        dest="soft_reset",
+    )
+    group = cmd_parser.add_mutually_exclusive_group()
+    group.add_argument(
+        "--follow",
+        action="store_true",
+        default=None,
+        help="follow the output after running the scripts [default if no scripts given]",
+    )
+    group.add_argument(
+        "--no-follow",
+        action="store_false",
+        dest="follow",
+    )
+    group = cmd_parser.add_mutually_exclusive_group()
+    group.add_argument(
+        "--exclusive",
+        action="store_true",
+        default=True,
+        help="Open the serial device for exclusive access [default]",
+    )
+    group.add_argument(
+        "--no-exclusive",
+        action="store_false",
+        dest="exclusive",
+    )
+    cmd_parser.add_argument(
+        "-f",
+        "--filesystem",
+        action="store_true",
+        help="perform a filesystem action: "
+        "cp local :device | cp :device local | cat path | ls [path] | rm path | mkdir path | rmdir path",
+    )
+    cmd_parser.add_argument("files", nargs="*", help="input files")
+    args = cmd_parser.parse_args()
+
+    # open the connection to the pyboard
+    try:
+        pyb = Pyboard(
+            args.device, args.baudrate, args.user, args.password, args.wait, args.exclusive
+        )
+    except PyboardError as er:
+        print(er)
+        sys.exit(1)
+
+    # run any command or file(s)
+    if args.command is not None or args.filesystem or len(args.files):
+        # we must enter raw-REPL mode to execute commands
+        # this will do a soft-reset of the board
+        try:
+            pyb.enter_raw_repl(args.soft_reset)
+        except PyboardError as er:
+            print(er)
+            pyb.close()
+            sys.exit(1)
+
+        def execbuffer(buf):
+            try:
+                if args.follow is None or args.follow:
+                    ret, ret_err = pyb.exec_raw(
+                        buf, timeout=None, data_consumer=stdout_write_bytes
+                    )
+                else:
+                    pyb.exec_raw_no_follow(buf)
+                    ret_err = None
+            except PyboardError as er:
+                print(er)
+                pyb.close()
+                sys.exit(1)
+            except KeyboardInterrupt:
+                sys.exit(1)
+            if ret_err:
+                pyb.exit_raw_repl()
+                pyb.close()
+                stdout_write_bytes(ret_err)
+                sys.exit(1)
+
+        # do filesystem commands, if given
+        if args.filesystem:
+            filesystem_command(pyb, args.files)
+            del args.files[:]
+
+        # run the command, if given
+        if args.command is not None:
+            execbuffer(args.command.encode("utf-8"))
+
+        # run any files
+        for filename in args.files:
+            with open(filename, "rb") as f:
+                pyfile = f.read()
+                if filename.endswith(".mpy") and pyfile[0] == ord("M"):
+                    pyb.exec_("_injected_buf=" + repr(pyfile))
+                    pyfile = _injected_import_hook_code
+                execbuffer(pyfile)
+
+        # exiting raw-REPL just drops to friendly-REPL mode
+        pyb.exit_raw_repl()
+
+    # if asked explicitly, or no files given, then follow the output
+    if args.follow or (args.command is None and not args.filesystem and len(args.files) == 0):
+        try:
+            ret, ret_err = pyb.follow(timeout=None, data_consumer=stdout_write_bytes)
+        except PyboardError as er:
+            print(er)
+            sys.exit(1)
+        except KeyboardInterrupt:
+            sys.exit(1)
+        if ret_err:
+            pyb.close()
+            stdout_write_bytes(ret_err)
+            sys.exit(1)
+
+    # close the connection to the pyboard
+    pyb.close()
+
+
+if __name__ == "__main__":
+    main()