How to auto-detect Arduino COM port?
- You can use SerialPort.GetPortNames() to return an array of string COM port names.
- I dont think you can auto detect the ports, youd have to ping the device in order to see if the device is connected.
This little bit of code has performed very well for this (returns the COM port string, i.e. "COM12" if Arduino is detected):
private string AutodetectArduinoPort()
{
ManagementScope connectionScope = new ManagementScope();
SelectQuery serialQuery = new SelectQuery("SELECT * FROM Win32_SerialPort");
ManagementObjectSearcher searcher = new ManagementObjectSearcher(connectionScope, serialQuery);
try
{
foreach (ManagementObject item in searcher.Get())
{
string desc = item["Description"].ToString();
string deviceId = item["DeviceID"].ToString();
if (desc.Contains("Arduino"))
{
return deviceId;
}
}
}
catch (ManagementException e)
{
/* Do Nothing */
}
return null;
}
Taking the WMI Management route a bit further, I've come up with a wrapper class which hooks on to the Win32_SerialPorts events and dynamically populated a list of SerialPorts for Arduino and Digi International (X-Bee) devices, complete with PortNames and BaudRates.
For now, I've used the devices Description field in the Win32_SerialPorts entry as the Key for the Dictionary, but this can easily be changed.
It has been tested to a limited capacity with an Arduino UNO and it seems to be stable.
// -------------------------------------------------------------------------
// <copyright file="ArduinoDeviceManager.cs" company="ApacheTech Consultancy">
// Copyright (c) ApacheTech Consultancy. All rights reserved.
// </copyright>
// <license type="GNU General Public License" version="3">
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see http://www.gnu.org/licenses
// <license>
// -------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.IO.Ports;
using System.Linq;
using System.Management;
using System.Runtime.CompilerServices;
// Automatically imported by Jetbeans Resharper
using ArduinoLibrary.Annotations;
namespace ArduinoLibrary
{
/// <summary>
/// Provides automated detection and initiation of Arduino devices. This class cannot be inherited.
/// </summary>
public sealed class ArduinoDeviceManager : IDisposable, INotifyPropertyChanged
{
/// <summary>
/// A System Watcher to hook events from the WMI tree.
/// </summary>
private readonly ManagementEventWatcher _deviceWatcher = new ManagementEventWatcher(new WqlEventQuery(
"SELECT * FROM Win32_DeviceChangeEvent WHERE EventType = 2 OR EventType = 3"));
/// <summary>
/// A list of all dynamically found SerialPorts.
/// </summary>
private Dictionary<string, SerialPort> _serialPorts = new Dictionary<string, SerialPort>();
/// <summary>
/// Initialises a new instance of the <see cref="ArduinoDeviceManager"/> class.
/// </summary>
public ArduinoDeviceManager()
{
// Attach an event listener to the device watcher.
_deviceWatcher.EventArrived += _deviceWatcher_EventArrived;
// Start monitoring the WMI tree for changes in SerialPort devices.
_deviceWatcher.Start();
// Initially populate the devices list.
DiscoverArduinoDevices();
}
/// <summary>
/// Gets a list of all dynamically found SerialPorts.
/// </summary>
/// <value>A list of all dynamically found SerialPorts.</value>
public Dictionary<string, SerialPort> SerialPorts
{
get { return _serialPorts; }
private set
{
_serialPorts = value;
OnPropertyChanged();
}
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public void Dispose()
{
// Stop the WMI monitors when this instance is disposed.
_deviceWatcher.Stop();
}
/// <summary>
/// Occurs when a property value changes.
/// </summary>
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// Handles the EventArrived event of the _deviceWatcher control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="EventArrivedEventArgs"/> instance containing the event data.</param>
private void _deviceWatcher_EventArrived(object sender, EventArrivedEventArgs e)
{
DiscoverArduinoDevices();
}
/// <summary>
/// Dynamically populates the SerialPorts property with relevant devices discovered from the WMI Win32_SerialPorts class.
/// </summary>
private void DiscoverArduinoDevices()
{
// Create a temporary dictionary to superimpose onto the SerialPorts property.
var dict = new Dictionary<string, SerialPort>();
try
{
// Scan through each SerialPort registered in the WMI.
foreach (ManagementObject device in
new ManagementObjectSearcher("root\\CIMV2", "SELECT * FROM Win32_SerialPort").Get())
{
// Ignore all devices that do not have a relevant VendorID.
if (!device["PNPDeviceID"].ToString().Contains("VID_2341") && // Arduino
!device["PNPDeviceID"].ToString().Contains("VID_04d0")) continue; // Digi International (X-Bee)
// Create a SerialPort to add to the collection.
var port = new SerialPort();
// Gather related configuration details for the Arduino Device.
var config = device.GetRelated("Win32_SerialPortConfiguration")
.Cast<ManagementObject>().ToList().FirstOrDefault();
// Set the SerialPort's PortName property.
port.PortName = device["DeviceID"].ToString();
// Set the SerialPort's BaudRate property. Use the devices maximum BaudRate as a fallback.
port.BaudRate = (config != null)
? int.Parse(config["BaudRate"].ToString())
: int.Parse(device["MaxBaudRate"].ToString());
// Add the SerialPort to the dictionary. Key = Arduino device description.
dict.Add(device["Description"].ToString(), port);
}
// Return the dictionary.
SerialPorts = dict;
}
catch (ManagementException mex)
{
// Send a message to debug.
Debug.WriteLine(@"An error occurred while querying for WMI data: " + mex.Message);
}
}
/// <summary>
/// Called when a property is set.
/// </summary>
/// <param name="propertyName">Name of the property.</param>
[NotifyPropertyChangedInvocator]
private void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}