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Member Since 08 Jul 2015
Offline Last Active Aug 01 2015 02:47 AM

#63574 Help on Netduino 2 Serial Communication to PC

Posted by yxhu on 18 July 2015 - 02:58 PM

Hi Chris,
I am new to this forums and this is my first post. Recently I have purchased a few ND2s. I setup a very small serial communication program and unfortunatey it didn't work as expected. Here is the setting:
On netduino, I am using COM4, the connection to the PC as:
ND            ----->  PC
SDA(RX)   ----     TX
SCL (TX)   ----     RX
Program runs on the ND:

private static SerialPort _serialPort;

public static void Main()
   _serialPort = new SerialPort("COM4", 9600, Parity.None, 8, StopBits.One);

    System.Text.UTF8Encoding encoder = new System.Text.UTF8Encoding();
    byte[] bytesToSend  = encoder.GetBytes("abc");

       _serialPort.Write(bytesToSend, 0, bytesToSend.Length);

Program runs on the PC:

public Program()
    _serialPort = new SerialPort();
    _serialPort.PortName     = "COM3";
    _serialPort.BaudRate     = 9600;
    _serialPort.DataBits     = 8;
    _serialPort.DiscardNull  = true;
    _serialPort.StopBits     = StopBits.One;
    _serialPort.Parity       = Parity.None;
    _serialPort.DataReceived += _serialPort_DataReceived;

private void _serialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
     var _buffer = new byte[_serialPort.BytesToRead];
      _serialPort.Read(_buffer, 0, _buffer.Length);


Basically, I wanted to let ND to keep sending string "abc" to the PC. After I have tried different Baud rates, i.e.  9600, 4800, 2400. I am always getting very wired result at PC end, please see the attached screenshot.


I suspect there might be the Baud rate mismatch. However, I have tripple checked my code, both sides have identical settings on the serial port.


I spent many hours googling with no luck.



On other weird thing was, I needed to set 'DiscardNull = true' on the PC end, otherwise I am getting massive '0x00' bytes from ND.


I am using VS2010, Micro Framework 4.2, Netdunio SDK I started with VS2013, Micro Framework 4.3, and Netduino SDK, unforturnately I couldn't debug the program on ND. I always get error  "The debuging target is not in an initialized state; rebooting......", So I have reverted everything back to VS2010, then I could debug the program.


I have also attached the output from "Device capabilities" in the MSDeploy FYI.









Attached Files

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