Determine which com port has Arduino attached

Projects General Guidance
1

In the IDE and in Visual Micro, it’s able to tell me if the com port is an Arduino DUE USB port or a Programming port.

Is it able to ask the Due this info or is it getting it from a Windows Driver for those ports?

I would like to do the same.

My first thought was that I could open the port with the special baud rate and ask it questions. If it supported that sort of thing.

2

Some boards with native USB support (like the Arduino Leonardo, Due, Uno R4, or ESP32 S3) can provide a VID (Vendor ID) and PID (Product ID) when connected. I guess the IDE could use these to suggest a matching board profile, but the actual board selection remains mostly a manual process.

3

one technique is for the host program to transmit a prompt over serial to the target microcontroller which responds with know text, e.g. in the case of a SIM_A7670E modem transmit AT+CGMM which responds with A7670E-LAS

e.g. using C# is call the SerialPort.GetPortNames Method then iterate thru the ports

// C# send prompt to serial ports looking for a apecific response

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO.Ports;
using System.Threading;

namespace ListCOMports
{
    class Program
    {
        static void Main(string[] args)
        {
            // Press Ctrl+F5 (or go to Debug > Start Without Debugging) to run your app.
            Console.WriteLine("COM ports");
            // Get a list of serial port names.
            string[] ports = SerialPort.GetPortNames();
            Console.WriteLine("The following serial ports were found:");
            // prompt each port with ? look for response "ESP32+BME280"
            foreach (string port in ports)
            {
                SerialPort serialPort1 = new SerialPort();
                Console.WriteLine(port); 
                try
                {
                    serialPort1.PortName = port;
                    serialPort1.Open();         // attempt to open serial port
                    serialPort1.BaudRate = 115200;
                    Console.WriteLine("serial port open OK {0}", serialPort1.PortName);
                    serialPort1.Write("?");     // prompt with ?
                    Thread.Sleep(100);
                    // check response (if any)
                    String response = serialPort1.ReadExisting();
                    Console.WriteLine("response " + response);
                    if (response.Contains("ESP32+BME280"))
                    {
                        Console.WriteLine("ESP32 with BME280 found !!!");
                    }
                    serialPort1.Close();                                                        //open OK, close it
                 }
                catch (Exception ex)
                { Console.WriteLine("serial port open fail {0} ", serialPort1.PortName, ex); }
            }
        }
    }
}

ESP32 test program

// ESP32 - on ? prompt respond with "ESP32+BME280"

void setup() {
  Serial.begin(115200);
  delay(2000);
  while (true) {
    char ch = Serial.read();
    if (ch == '?')
      Serial.println("ESP32+BME280");
    if (ch == 'G') break;
  }
  Serial.println("program found");
}

void loop() {}

when run the C# program console displays

COM ports
The following serial ports were found:
COM1
serial port open fail COM1
COM6
serial port open fail COM6
COM18
serial port open OK COM18
response ESP32+BME280

ESP32 with BME280 found !!!
Press any key to continue . . .