Get Data from Bluetooth device in C#

Question

I'm trying to get data from a medical BT device that I already have pairing code and communication protocol.

Looking for some code I've got this code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using InTheHand.Net.Sockets;
using InTheHand.Net;
using InTheHand.Net.Bluetooth;
using InTheHand.Windows.Forms;
using System.Net.Sockets;
using System.Diagnostics;
using System.Threading;

namespace dConsoleApp
{
    static class Program
    {
        // My BT USB adapter
        private static BluetoothEndPoint EP = new BluetoothEndPoint(BluetoothAddress.Parse("00:02:72:CD:9A:33"), BluetoothService.BluetoothBase);
        private static BluetoothClient BC = new BluetoothClient(EP);

        // The BT device that would connect
        private static BluetoothDeviceInfo BTDevice = new BluetoothDeviceInfo(BluetoothAddress.Parse("94:21:97:60:07:C0"));

        private static NetworkStream stream = null;

        static void Main(string[] args)
        {
            if (BluetoothSecurity.PairRequest(BTDevice.DeviceAddress, MY_PAIRING_CODE))
            {
                Console.WriteLine("PairRequest: OK");

                if (BTDevice.Authenticated)
                {
                    Console.WriteLine("Authenticated: OK");

                    BC.SetPin(MY_PAIRING_CODE);

                    BC.BeginConnect(BTDevice.DeviceAddress, BluetoothService.SerialPort, new AsyncCallback(Connect), BTDevice);
                }
                else
                {
                    Console.WriteLine("Authenticated: No");
                }
            }
            else
            {
                Console.WriteLine("PairRequest: No");
            }

            Console.ReadLine();
        }

    private static void Connect(IAsyncResult result)
    {
        if (result.IsCompleted)
        {
            // client is connected now :)
            Console.WriteLine(BC.Connected);
            stream = BC.GetStream();

            if (stream.CanRead)
            {
                byte[] myReadBuffer = new byte[1024];
                StringBuilder myCompleteMessage = new StringBuilder();
                int numberOfBytesRead = 0;

                // Incoming message may be larger than the buffer size. 
                do
                {
                    numberOfBytesRead = stream.Read(myReadBuffer, 0, myReadBuffer.Length);

                    myCompleteMessage.AppendFormat("{0}", Encoding.ASCII.GetString(myReadBuffer, 0, numberOfBytesRead));
                }
                while (stream.DataAvailable);

                // Print out the received message to the console.
                Console.WriteLine("You received the following message : " + myCompleteMessage);
            }
            else
            {
                Console.WriteLine("Sorry.  You cannot read from this NetworkStream.");
            }

            Console.ReadLine();       
        }
    }
}

}

And this is the console result:

While I expect something like 0XA5 0x05 0x04 0x01 etc. etc.

Can you help me to get the correct result?

Boldfaced

instead of Encoding.ASCII, try using UTF8 or Unicode.. do you know what is your source encoding? – Valletta

Hello, I've already tried other Encoding but I get only other symbols as result. No, in the communication protocol that I've there is not specified the source encoding. – Boldfaced

Answer 1

You want to replace the following:

myCompleteMessage.AppendFormat("{0}", Encoding.ASCII.GetString(myReadBuffer, 0, numberOfBytesRead));

with

for (int i = 0; i < numberOfBytesRead; i++)
    myCompleteMessage.AppendFormat("0x{0:X2} ", myReadBuffer[i]);

Rapids

Thank you! This was the mistake. Now I can read the bytes from the device. But how can I now convert the bytes in something more readable? – Boldfaced

@YiyiChen Well, it depends on your medical device. It should have some documentation with it about protocol/messages format. – Rapids

It's the first time that I do something like this. I saw if I put a break point on for (int i = 0; i < numberOfBytesRead; i++) in the debug mode I can see the data in the myReadBuffer variable. This is the communication protocol: dropbox.com/s/kmh627o53rzghwr/Communication%20protocol.pdf , can you tell me what type format it uses? – Boldfaced