PORTS Forum
Ports and Interfaces => Serial Ports => Topic started by: GlennP on December 13, 2012, 08:16:22 am
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Hi All,
Same board I was fiddling with all week being that I have to get some thing done and out to a customer Today. I have to talk to a board the same as HyperTerminal. My first step was to look over the comms spec 2400, 8, None, 1 and set a program to send out a command (in C#) using an application I have written the sending routine is
private void rtbOutgoing_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)13) // enter key
{ myComPort.Write("\r\n");
Thread.Sleep(200);
rtbOutgoing.Text = "";
}
else if (e.KeyChar < 32 || e.KeyChar > 126)
{
e.Handled = true; // ignores anything else outside printable ASCII range
}
else
{
myComPort.Write(e.KeyChar.ToString());
} This routine works for sending out what evers in the output text box (rtbOutgoing keypress routine).
This appears not to work so I tried to use a routine that was developed to ensure all data from a reply was got.
private string Write_Board(string Data_To_Board)
{
Pause.Start();
myComPort.Write(Data_To_Board + (char)10 + (char)13);
{
while (Reply_Status == (int)REPLY.NO_REPLY)
{
NoDataAtPort.Enabled = true;
}
NoDataAtPort.Enabled = false;
if (Reply_Status == (int)REPLY.TIMEOUT_REPLY)
{
Data_From_Board = "TIMEOUT\n";
Pause.Stop();
}
else if (Reply_Status == (int)REPLY.YES_REPLY)
{
Pause.Stop();
//add try catch
try
{
InputData = myComPort.ReadExisting();
if (InputData != String.Empty)
{
this.BeginInvoke(new SetTextCallback(SetText), new object[] { InputData });
ProcessInput();
}
else if (InputData == String.Empty)
{
return (null);
}
}
catch (UnauthorizedAccessException)
{
MessageBox.Show("Error Caught!!" );
}
}
else
{
Cursor.Current = Cursors.No;
Reply_Status = (int)REPLY.NO_REPLY;
}
}
// ProcessInput();
// Data_From_Board = Data_From_Board + "|||";
// return (Data_From_Board);
return("");
}
This was called by the line of code Write_Board(command) example follows
Reply_Status = (int)REPLY.NO_REPLY;
Write_Board("/");
Reply Status is an Enumerated list as follows
enum REPLY : int { NO_REPLY, TIMEOUT_REPLY, YES_REPLY }
The Data Recieved Event has the following
private void port_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
Reply_Status = (int)REPLY.YES_REPLY;
}
I was a little supprised when this worked and returned data. As this method had originally created for ensuring the complete command was sent. As I mentioned earlier (previous question) this board uses a one wire interface for communications so I get back an echo of what I sent (not a problem I can filter out these replies) I am playing at Debugging/Trying ideas while I am typing this,
I have a dodgy solution at the moment in that if I send the command twice with a gap from a Thread Sleep, while this is not ideal (far from it) it does appear to work, however I will need a proper solution quickly. As far as I can see I am doing everything properly. This board is being troublesome. Can anyone give me a pointer (or website/book recomendation) to doing single wire comms, as Sending the commands twice to get a reply is awkward, on the a spy HyperTerminal window I have set up a second USB serial port to spy on the Comms with the board I can see it is replying twice but my program will only display the second. WHY???
Glenn
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See if this helps:
http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/b1bc8785-e94e-46b6-9303-ed0f27b49bdb/
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Hmm...Looks like it might, I also believe that the NEC part is in 1/2 Duplex mode that is possible why I need to send each command twice to get a responce. I will look at that more throughly tomorrow as it has been a long day!
Glenn!