feat(tools/monitor): add simple port detection

Closes https://github.com/espressif/esp-idf/issues/8114

tools/idf_monitor.py

@@ -9,7 +9,7 @@
 # - If core dump output is detected, it is converted to a human-readable report
 #   by espcoredump.py.
 #
-# SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 #
 # Contains elements taken from miniterm "Very simple serial terminal" which
@@ -33,7 +33,6 @@ from builtins import bytes
 from typing import Any, List, Optional, Type, Union
 
 import serial
-import serial.tools.list_ports
 # Windows console stuff
 from idf_monitor_base.ansi_color_converter import get_ansi_converter
 from idf_monitor_base.argument_parser import get_parser
@@ -53,7 +52,7 @@ from idf_monitor_base.output_helpers import normal_print, yellow_print
 from idf_monitor_base.serial_handler import SerialHandler, SerialHandlerNoElf, run_make
 from idf_monitor_base.serial_reader import LinuxReader, SerialReader
 from idf_monitor_base.web_socket_client import WebSocketClient
-from serial.tools import miniterm
+from serial.tools import list_ports, miniterm
 
 key_description = miniterm.key_description
 
@@ -291,6 +290,21 @@ def main() -> None:
     # avoid the modification of args.port.
     port = args.port
 
+    # if no port was set, detect connected ports and use one of them
+    if port is None:
+        try:
+            port_list = list_ports.comports()
+            port = port_list[-1].device
+            # keep the `/dev/ttyUSB0` default port on linux if connected
+            if sys.platform == 'linux':
+                for p in port_list:
+                    if p.device == '/dev/ttyUSB0':
+                        port = p.device
+                        break
+            yellow_print(f'--- Using autodetected port {port}')
+        except IndexError:
+            sys.exit('No serial ports detected.')
+
     # GDB uses CreateFile to open COM port, which requires the COM name to be r'\\.\COMx' if the COM
     # number is larger than 10
     if os.name == 'nt' and port.startswith('COM'):

tools/idf_monitor_base/argument_parser.py

@@ -1,8 +1,9 @@
-# SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 
 import argparse
 import os
+import sys
 
 from .constants import DEFAULT_PRINT_FILTER, DEFAULT_TOOLCHAIN_PREFIX, PANIC_DECODE_BACKTRACE, PANIC_DECODE_DISABLE
 from .coredump import COREDUMP_DECODE_DISABLE, COREDUMP_DECODE_INFO
@@ -13,8 +14,9 @@ def get_parser():  # type: () -> argparse.ArgumentParser
 
     parser.add_argument(
         '--port', '-p',
-        help='Serial port device',
-        default=os.environ.get('ESPTOOL_PORT', '/dev/ttyUSB0')
+        help='Serial port device. If not set, a connected port will be used.' +
+        (' Defaults to `/dev/ttyUSB0` if connected.' if sys.platform == 'linux' else ''),
+        default=os.environ.get('ESPTOOL_PORT', None)
     )
 
     parser.add_argument(

tools/idf_monitor_base/serial_reader.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 
 import queue
@@ -7,6 +7,7 @@ import sys
 import time
 
 import serial
+from serial.tools import list_ports
 
 from .constants import CHECK_ALIVE_FLAG_TIMEOUT, MINIMAL_EN_LOW_DELAY, RECONNECT_DELAY, TAG_SERIAL
 from .output_helpers import red_print, yellow_print
@@ -49,7 +50,13 @@ class SerialReader(Reader):
             self.serial.rts = high     # IO0=HIGH
             self.serial.dtr = self.serial.dtr   # usbser.sys workaround
             # Current state not reset the target!
-            self.serial.open()
+            try:
+                self.serial.open()
+            except serial.serialutil.SerialException:
+                # if connection to port fails suggest other available ports
+                port_list = '\n'.join([p.device for p in list_ports.comports()])
+                yellow_print(f'Connection to {self.serial.portstr} failed. Available ports:\n{port_list}')
+                return
             if not self.gdb_exit and self.reset:
                 self.serial.dtr = high     # Set dtr to reset state (affected by rts)
                 self.serial.rts = low      # Set rts/dtr to the reset state