Develop Reference

Serial port communication issue from c# to c application

I am writing a c#application which communicates with a device c application.
I am trying to write data from the c# application to c application over the serial port and vice versa.
I am trying to write some sample data using the following code.
C#
using PORT = System.IO.Port.SerialPort;
PORT p = new PORT("COM4", 9600, System.IO.Ports.Parity.None, 8, System.IO.Ports.StopBits.One);
string data="HELLO";
//String to byte[] conversion
byte[] byt_buff = new byte[data.Length];
byt_buff = Encoding.ASCII.GetBytes(data);
p.Open();
p.DiscardOutBuffer();
p.Write(byt_buff, 0, byt_buff.Length);
p.Close();
The c application running on the device has the following code.
C
#include<stdio.h>
#include <poll.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include<stdint.h>
#include<string.h>
#define USB_DEV_NODE "usb.dat"
#define MAX_SIZE 20
int main()
{
int fd;
int ret_poll;
int ret_read;
struct pollfd pollfd;
char buf[MAX_SIZE];
int i = 0;
pollfd.events = POLLIN;
fd = open(USB_DEV_NODE, O_RDWR | O_NOCTTY);
pollfd.fd = fd;
while (1)
{
ret_poll = poll( &pollfd, 1, -1);
if( ret_poll == -1 )
{
printf("Gpio_poll poll failed\r\n");
close(fd);
}else{
if (pollfd.revents & POLLIN )
{
ret_read = read(fd, buf, MAX_SIZE);
buf[ret_read]=0;
if(ret_read > 0)
{
for(i=0;i<ret_read ; i++)
{
printf("BUF[%d]=%c\n",i,buf[i]);
}
}
}
}
}
return 0;
}
But I am failing to receive the data written as byte[],No data is recieved. Instead if I write data as a string using p.WriteLine("HELLO"); it will be recieved. Please help.

C#: Waiting for specific character sent from RS485

In my app I am sending data to microcontroller. I send data, microcontroller do program, and send character ("K"). My application should wait for this character.After receiving this char, it should send data again.
I got problem with receiving this character. Is function BytesToRead right to reading character? My program always fall when it reach this my function wait
static void wait()
{
SerialPort COMport = new SerialPort();
int znak;
COMport.PortName = "COM6"; //
COMport.BaudRate = 1200;
COMport.DataBits = 8;
COMport.Parity = Parity.None;
COMport.StopBits = StopBits.One;
COMport.Open();
do
{
znak = COMport.BytesToRead;
} while (znak != 75); // ASCII K = 75
COMport.Close();
return;
}

The BytesToRead property of the COMport returns the number of characters that have been received by the COMport so your loop will continue until there are exactly 75 characters read. Take a look at the documentation for the SerialPort class. It will show you a good example of how to read/write characters from/to your COMport.

Why not just use while(COMport.ReadChar() != 'K') { /* Do Stuff */ }?

c# named pipe two way communcation

I have two programs written in c++ and c#.I want to establish a two way communication using named-pipe between them. The C# client program can be connected to the named-pipe created by c++ server program.But nothing received in both ends.
Here is the c++ part (Server):
#include <iostream>
#include <windows.h>
#include <stdlib.h>
#define UNICODE
using namespace std;
HANDLE hnamedPipe = INVALID_HANDLE_VALUE;
BOOL Finished =false;
HANDLE hThread = NULL;
unsigned long __stdcall CS_RcvThr(void * pParam) ;
int main(int argc, char **argv)
{
hnamedPipe = CreateNamedPipe(
"\\\\.\\pipe\\vikeyP",
PIPE_ACCESS_DUPLEX,
PIPE_TYPE_MESSAGE|
PIPE_READMODE_MESSAGE|
PIPE_WAIT,
PIPE_UNLIMITED_INSTANCES,
1024,
1024,
NMPWAIT_USE_DEFAULT_WAIT,
NULL);
if(hnamedPipe == INVALID_HANDLE_VALUE)
{
cout << "Failed" << endl;
}
while (true)
{
cout<< "Waiting for client"<< endl;
if(!ConnectNamedPipe(hnamedPipe,NULL))
{
if(ERROR_PIPE_CONNECTED != GetLastError())
{
cout << "FAIL"<< endl;
}
}
else
{
cout<<"Connected!"<<endl;
hThread = CreateThread( NULL, 0, &CS_RcvThr, NULL, 0, NULL);
if(hThread) cout<<"read thread created"<<endl; else cout<<"cant crat rd thed\n";
break;
}
}
while(1)
{
cout<<"lst loop"<<endl;
//Send over the message
char chResponse[] = "hello\n";
DWORD cbResponse,cbWritten;
cbResponse = sizeof(chResponse);
if (!WriteFile(
hnamedPipe,
chResponse,
cbResponse,
&cbWritten,
NULL))
{
wprintf(L"failiure w/err 0x%08lx\n",GetLastError);
}
cout<<"Sent bytes :)" << endl;
Sleep(10);
}
}
unsigned long __stdcall CS_RcvThr(void * pParam) {
BOOL fSuccess;
char chBuf[100];
DWORD dwBytesToWrite = (DWORD)strlen(chBuf);
DWORD cbRead;
int i;
while (1)
{
fSuccess =ReadFile( hnamedPipe,chBuf,dwBytesToWrite,&cbRead, NULL);
if (fSuccess)
{
printf("C++ App: Received %d Bytes : ",cbRead);
for(i=0;i<cbRead;i++)
printf("%c",chBuf[i]);
printf("\n");
}
if (! fSuccess && GetLastError() != ERROR_MORE_DATA)
{
printf("Can't Read\n");
if(Finished)
break;
}
}
}
Here is the C# part (Client):
private Thread vikeyClientThread;
public void ThreadStartClient()
{
Console.WriteLine("Thread client started ID ={0} name = {1} " ,
Thread.CurrentThread.ManagedThreadId,Thread.CurrentThread.Name);
using (NamedPipeClientStream pipeStream = new NamedPipeClientStream(".", "vikeyP"))
{
// The connect function will indefinately wait for the pipe to become available
// If that is not acceptable specify a maximum waiting time (in ms)
Console.WriteLine("Connecting to ViKEY server...");
pipeStream.Connect();
Console.WriteLine("Connected :)");
//Write from client to server
StreamWriter sw = new StreamWriter(pipeStream);
while (true)
{
//Read server reply
StreamReader sr = new StreamReader(pipeStream);
string temp = "";
sw.WriteLine(System.DateTime.Now);
byte[] c = new byte[200];
temp = sr.ReadLine();
pipeStream.Read(c, 0, c.Length);
Console.WriteLine("RX =:{0}", Encoding.UTF8.GetString(c, 0, c.Length));
Thread.Sleep(500);
}
}
Console.WriteLine("Vikey pipe Closed");
Console.WriteLine("Thread with ID ={0} name = {1} is closed.",
Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.Name);
}

You've set the server side up as a message type vs byte type. If you want to read an arbitrary number of bytes, you'll need to use a byte type named pipe.
You're wrapping the stream in 2 objects one StreamReader and one StreamWriter. Don't do that, just use a Stream. You're trying to read by line, don't do that either. Instead send the number of bytes to read followed by the bytes. On the client side you'll read the byte count then create a buffer big enough then read. If it's text data you then would use an encoder (probably ASCII) to translate it back into a C# string.
Your while(true) should instead detect when the server has closed the pipe.
You should probably look into using an asynchronous named pipe.

Getting Callerid from serial port with Conexant USB CX93010 modem?

I have a C# code but it doesn't takes a CallerID from dial up modem connected to USB port when I connect line to phone. It gets CallerID but in program run and in reading line I have just RING nothing else.
This is my code:
public partial class Form1 : XtraForm
{
public Form1()
{
InitializeComponent();
}
SerialPort sp ;
private void simpleButton1_Click(object sender, EventArgs e)
{
sp = new SerialPort(textEdit1.Text);
sp.NewLine = "\r\n";
sp.Parity = Parity.None;
sp.DataBits = 8;
sp.StopBits = StopBits.One;
sp.DtrEnable = true;
sp.WriteBufferSize = 1024;
sp.Open();
sp.WriteLine("AT+VCID=1");
sp.RtsEnable = true;
timer1.Start();
}
void sp_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
sp.Close();
}
private void timer1_Tick(object sender, EventArgs e)
{
memoEdit1.Text += "\n" + sp.ReadExisting();
}
private void simpleButton2_Click(object sender, EventArgs e)
{
sp.Close();
}

Conexant USB CX93010 ACF Modem don't have FSK protocol

When your modem supports caller id then make use of AT+CLIP=1. This will cause unsolicited +CLIP messages to be displayed when the modem is called.
The +CLIP unsolicited messages are usually formulated as follows:
+CLIP: <number>,<type>,,,,<cli validity>
Where <number> is a string containing the number in a format defined by <type>. <type> of address octet which for example for international numbers is 145. <cli validity> determines whether the number was withheld etc.

I'm posting the code below based on some testing I was doing with the Conexant USB CX93010. The code below is in C (rather than C#) and runs on Linux (rather than Windows). But it should provide a good baseline for a C# program.
The code is based on another Stack Overflow answer written by Sawdust, and it has test results from the program.
You can also find a comprehensive AT command set for Conexant modems at http://www.arcelect.com. It is dated from 2001, but it has more AT commands for the modems than I found elsewhere on the web.
Here is the code.
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#define DISPLAY_STRING 1
int set_interface_attribs(int fd, int speed)
{
struct termios tty;
if (tcgetattr(fd, &tty) < 0) {
printf("Error from tcgetattr: %s\n", strerror(errno));
return -1;
}
cfmakeraw (&tty);
cfsetospeed(&tty, (speed_t)speed);
cfsetispeed(&tty, (speed_t)speed);
if (tcsetattr(fd, TCSANOW, &tty) != 0) {
printf("Error from tcsetattr: %s\n", strerror(errno));
return -1;
}
return 0;
}
void write_command(int fd, const void* cmd, size_t len)
{
if (len == ~(size_t)0)
len = strlen((const char*)cmd);
printf("Send %d: %s\n", (int)len, (const char*)cmd);
int wlen = write(fd, cmd, len);
if (wlen != len) {
printf("Error from write: %d, %d\n", wlen, errno);
}
tcdrain(fd); /* delay for output */
}
void read_response(int fd)
{
char buf[256];
int rlen = read(fd, buf, sizeof(buf) - 1);
if (rlen > 0) {
#ifdef DISPLAY_STRING
buf[rlen] = 0;
printf("Read %d: \"%s\"\n", rlen, buf);
#else /* display hex */
unsigned char *p;
printf("Read %d:", rlen);
for (p = buf; rlen-- > 0; p++)
printf(" 0x%x", *p);
printf("\n");
#endif
} else if (rlen < 0) {
printf("Error from read: %d: %s\n", rlen, strerror(errno));
} else { /* rlen == 0 */
printf("Timeout from read\n");
}
}
int main(int argc, char* argv[])
{
int fd;
const char portname[] = "/dev/ttyACM0";
fd = open(portname, O_RDWR | O_NOCTTY | O_SYNC);
if (fd < 0) {
printf("Error opening %s: %s\n", portname, strerror(errno));
return -1;
}
/*baudrate 115200, 8 bits, no parity, 1 stop bit */
set_interface_attribs(fd, B115200);
write_command(fd, "ATZ\r", 4); /* Reset */
read_response(fd);
write_command(fd, "ATE0\r", -1); /* Echo off */
read_response(fd);
write_command(fd, "AT+VCID=?\r", -1); /* Query CallerID caps */
read_response(fd);
write_command(fd, "AT+CLIP=?\r", -1); /* Query CallerID caps */
read_response(fd);
write_command(fd, "AT+VCID=1\r", -1); /* Set CallerID */
read_response(fd);
printf("Entering loop, CTRL+C to break...\n\n");
while (1)
{
read_response(fd);
}
return 0;
}
Here are the test results using a cell phone. I changed the name and phone number; other wise it is the exact output of the program.
$ sudo ./modem.exe
Send 4: ATZ
Read 6: "
OK
"
Send 5: ATE0
Read 11: "ATE0
OK
"
Send 10: AT+VCID=?
Read 15: "
(0-2)
OK
"
Send 10: AT+CLIP=?
Read 9: "
ERROR
"
Send 10: AT+VCID=1
Read 6: "
OK
"
Entering loop, CTRL+C to break...
Read 8: "
RING
"
Read 67: "
DATE = 0214
TIME = 2116
NMBR = 2025551212
NAME = JANE DOE
"
Read 8: "
RING
"
Read 67: "
DATE = 0214
TIME = 2116
NMBR = 2025551212
NAME = JANE DOE
"
Read 8: "
RING
"
Read 8: "
RING
"
Read 8: "
RING
"
Also, you can send an AT+GSR to get the real modem revision instead of what Windows provides (which appears to be a little inaccurate):
Send 7: AT+GMR
Read 44: "AT+GMR
+GMR: CX93001-EIS_V0.2013-V92
OK"

You must set Country of Installation to B5 by AT+GCI=B5 I got it after a three weeks of investigations (It may defer in your country it can be 00 or B4 or B5 but B5 for works for most of land lines):
Then enable CID reporting by AT+VCID=1 or AT+VCID=2 as it said in manual:
And then it works flawlessly:
And this is my working code based on yours:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO.Ports;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace CIDResolver
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
SerialPort sp;
private void Connect_click(object sender, EventArgs e)
{
sp = new SerialPort(textEdit1.Text);
sp.BaudRate = 11500;
sp.NewLine = "\r\n";
sp.Open();
sp.WriteLine("AT+GCI=B5"); // can be 00 or B4 or B5
sp.WriteLine("AT+VCID=1");
sp.DataReceived += new SerialDataReceivedEventHandler((object _s, SerialDataReceivedEventArgs _e) =>
{
string newData = sp.ReadExisting();
consoleOut.Invoke((MethodInvoker)delegate {
// Running on the UI thread
consoleOut.Text += newData+ "\r\n";
});
});
}
private void disConnectBtn_Click(object sender, EventArgs e)
{
sp.Close();
}
private void Form1_FormClosed_1(object sender, FormClosedEventArgs e)
{
sp.Close();
}
}
}

Convert serial port application from C# to C in visual studio (ERROR_INVALID_PARAMETER) 87

I am trying to write an app in C to communication with a device through a COM port.
I am able to send data using Docklight (hyper terminal like program) with the following settings and I can verify that I am receiving it through Itronix LogicPort Logic Analyzer.
Baud rate:9600
Parity:None
Byte Size:8
Stop bits:1
I am having 2 problems with my C program:
1) sometimes CreateFile returns INVALID_HANDLE_VALUE
and the other problem I can't seem to get by is that
GetCommState()
SetCommState()
SetCommTimeouts()
always return ERROR_INVALID_PARAMETER 87 (0x57)
Since I couldn't get past this problem, I tried a program in C# and that works just fine, but my program must be in C to communicate with the rest of my code. This program also communicates with other programs in C through sockets.
in Device Manager the device I want to talk to is listed as COM6 under Ports(COM & LPT)
any help would be appreciated!
Below is the code for both programs:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
byte[] TxBuffer = new byte[20];
SerialPort CommPort = new SerialPort("COM6", 9600, Parity.None, 8, StopBits.One);
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
CommPort.Open();
TxBuffer[0] = (byte)'|';
TxBuffer[1] = 0;
TxBuffer[2] = 0;
TxBuffer[3] = 0;
TxBuffer[4] = 1;
TxBuffer[5] = 100;
TxBuffer[6] = 1;
TxBuffer[7] = 6;
TxBuffer[8] = (byte)'|';
TxBuffer[9] = 1;
}
private void button1_Click(object sender, EventArgs e)
{
CommPort.Write(TxBuffer, 0, 10);
}
}
}
and the C code is:
somewhere
struct serial_dev {
HANDLE hSerial;
};
struct serial_dev sdev; //global
//somewhere in main
if (init_serial(&sdev, com_file) == -1)
return -1;
write_ser(&sdev, buffer, buf_size);
close_serial(&sdev);
// in serial.c
int init_serial(struct serial_dev *sdev, char *port_name)
{
DCB dcbSerialParams;
COMMTIMEOUTS timeouts;
int error = 0;
memset(&dcbSerialParams, 0, sizeof(dcbSerialParams));
memset(&timeouts, 0, sizeof(timeouts));
sdev->hSerial = CreateFile("COM6", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
if (sdev->hSerial == INVALID_HANDLE_VALUE)
{
error = GetLastError();
close_serial(sdev);
fprintf(stderr, "error: could not open serial port (error:%d)\n", error);
return -1;
}
memset(&dcbSerialParams, 0, sizeof(dcbSerialParams));
dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
if (!GetCommState(sdev->hSerial, &dcbSerialParams))
{
close_serial(sdev);
error = GetLastError();
fprintf(stderr, "error: could not get serial port state (%d)\n", error);
return -1;
}
dcbSerialParams.BaudRate = CBR_9600;
dcbSerialParams.ByteSize = 8;
dcbSerialParams.StopBits = ONESTOPBIT;
dcbSerialParams.Parity = NOPARITY;
if (!SetCommState(sdev->hSerial, &dcbSerialParams))
{
close_serial(sdev);
error = GetLastError();
fprintf(stderr, "error: could not set serial port state (%d)\n", error);
return -1;
}
timeouts.ReadIntervalTimeout = 50;
timeouts.ReadTotalTimeoutConstant = 200;
timeouts.ReadTotalTimeoutMultiplier = 10;
timeouts.WriteTotalTimeoutConstant = 50;
timeouts.WriteTotalTimeoutMultiplier = 10;
if (!SetCommTimeouts(sdev->hSerial, &timeouts))
{
close_serial(sdev);
error = GetLastError();
fprintf(stderr, "error: could not set serial port timeouts (%d)\n", error);
return -1;
}
return 0;
}
void close_serial(struct serial_dev *sdev)
{
CloseHandle(sdev->hSerial);
}
int write_ser(struct serial_dev *sdev, void *buf, size_t len)
{
DWORD written;
BOOL success;
success = WriteFile(sdev->hSerial, buf, len, &written, NULL);
if(!success || written == 0)
{
printf("error writing to serial\n");
return -1;
}
printf("writing to serial OK!\n");
return written;
}

guys I figured it out... I removed the "UNICODE" and "_UNICODE" preprocessor macros from my project settings and set it to "Not Set" found answer here: http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/1a77c595-10a5-4f14-8512-c67535c53a08/