My code can not recognize some characters that I sent from microcontroller

Question

0.00/5 (No votes)

See more:

Hi all, my name is Josev and I'm a newbie here.

I'm working to build receiver program with visual studio (C#) to receive data from my microcontroller. My PC connected to XBee via USB and read the data through COM port. The string data from microcontroller has been encrypted using aes128. But some characters can't be recognized by my PC, resulting in decrypting process failure. Here some example of my data :

real data : @A1@3.2@4.5@ (string)
data sent from my micro : »ËÌùû3arå*\
data received by my pc : ??????3ar??*\

Some characters can't be recognized and become "?"
I use ReadLine() to read COM port and catch it in string variable like this.

C#

String data = ComPort.ReadLine();

But when I check it by print it on my checkbox, some characters become "?". I took a screenshot in this link.

Please, really need help.

Posted 23-Sep-15 23:38pm

Member 12008308

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2015-09-23T23:56:00

Solution 1

Stop trying to receive it as a string, and fetch it as byte data instead: the chances are that the data from the microcontroller isn't Unocode, which the ReadLine method will assume it is.

So read it as bytes, and look at what values you are getting - and look at what the uController is supposed to be sending - chances are it isn't meant to be directly human readable...
https://msdn.microsoft.com/en-us/library/ms143549(v=vs.110).aspx[^] may help.

Posted 23-Sep-15 23:56pm

OriginalGriff

Comments

CPallini 24-Sep-15 6:19am

5.

Member 12008308 24-Sep-15 23:37pm

I try to use this method :

int databytes = ComPort.BytesToRead;
byte[] byte_buffer = new byte[databytes];
ComPort.Read(byte_buffer, 0, databytes);

I know it's catching something but I have no idea how to show the data inside databytes.

CPallini 25-Sep-15 3:03am

You may, for instance, print out the hexadecimal representation of such bytes, e.g.
foreach (byte b in byte_buffer)
Console.Write(" {0:X2}", b);
Console.WriteLine();

Member 12008308 27-Sep-15 20:12pm

It works. Thanks.