Comments by vinod b v

vinod b v 24-Apr-15 10:18am View

No it doesnt respond as required, but when i just transfer the OF at 200bps alone without sending the rest of the bytes it works just perfect, when i try to send all together i dont get my 25ms low and high pattern.

vinod b v 24-Apr-15 9:54am View

I am connected to an oscilloscope, where i can view whats happening. When i send F0 @ 200bps i get a low and high for 25ms respectively.next i need to send the 5 bytes @10400.

vinod b v 24-Apr-15 9:30am View

I want to send data to USB to serial converter and implement a wakeup pattern.send F0 at 200 bps and then send rest 5 bytes of data. i need to loop it continously.

vinod b v 24-Apr-15 6:36am View

yes i am having a problem with this code now. I need just a loop so that the data moves continously i tried while but with no success.i am totally confused with this now

vinod b v 24-Apr-15 6:13am View

Yes i will modify my question and post.

vinod b v 22-Apr-15 5:47am View

I did change it, but only F0 at 200 baud rate is being transferred, but unable to view the next 5 bytes at 10400 baud rate, i have updated the question.

vinod b v 22-Apr-15 5:37am View

Deleted

@phil.o As per solution 1 and your solution i changed the code but i am able to see only F0 being transferred but not the rest of the bytes, i am attaching my code please have a look.
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <dos.h>
#include<process.h>
#define true 1

int main()
{
// int _kbhit();
// int _getch();

// Defining hexadecimal bytes to be sent a 200 bps for generation of low high sequence//
unsigned char bytes_to_send[1];
bytes_to_send[0] = 0xF0; /* 11110000b */
unsigned char databytes_send[5];
databytes_send[0] = 0x81;
databytes_send[1] = 0x11;
databytes_send[2] = 0xF1;
databytes_send[3] = 0x11;
databytes_send[4] = 0x04;

/* int GetPressedKey()
{
int ret = 0;
if (_kbhit())
{
ret = _getch();
}
return ret;
} */
// Declare variables and structures//
HANDLE hSerial;
DCB dcbSerialParams = {0};
COMMTIMEOUTS timeouts = {0};

// Open the available serial port number//
fprintf(stderr, "Opening serial port...");
hSerial = CreateFile(
"COM4", GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );
if (hSerial == INVALID_HANDLE_VALUE)
{
fprintf(stderr, "Check for port connections\n");
return 1;
}
else
fprintf(stderr, "OK\n");
// Set device parameters (200 baud, 1 start bit,
// 1 stop bit, no parity)
dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
if (GetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error getting device state\n");
CloseHandle(hSerial);
return 1;
}

// Set baudrate to send bytes at 200 bps//
dcbSerialParams.BaudRate = 200;
dcbSerialParams.ByteSize = 8;
dcbSerialParams.StopBits = ONESTOPBIT;
dcbSerialParams.Parity = NOPARITY;
if(SetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error setting device parameters\n");
CloseHandle(hSerial);
return 1;
}

// Set COM port timeout settings//
timeouts.ReadIntervalTimeout = 50;
timeouts.ReadTotalTimeoutConstant = 50;
timeouts.ReadTotalTimeoutMultiplier = 10;
timeouts.WriteTotalTimeoutConstant = 50;
timeouts.WriteTotalTimeoutMultiplier = 10;
if(SetCommTimeouts(hSerial, &timeouts) == 0)
{
fprintf(stderr, "Error setting timeouts\n");
CloseHandle(hSerial);
return 1;
}
while(true)
{
// Send specified text (remaining command line arguments)
DWORD bytes_written = 0;
fprintf(stderr, "sending bytes...\n");

while(1)
{

//Transmit slow initialization data
if (!WriteFile(hSerial, bytes_to_send, 1,&bytes_written, NULL))

// break;
fprintf(stderr, "%d bytes written\n", bytes_written);

//check for key press event
/* if (GetPressedKey()) */

// break;
}

// Open the available serial port number//

// Set device parameters (200 baud, 1 start bit,
// 1 stop bit, no parity)
dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
if (GetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error getting device state\n");
CloseHandle(hSerial);
return 1;
}
// Set baudrate to send bytes at 10400 bps 8 N 1//

dcbSerialParams.BaudRate = 10400;
dcbSerialParams.ByteSize = 8;
dcbSerialParams.StopBits = ONESTOPBIT;
dcbSerialParams.Parity = NOPARITY;
if(SetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error setting device parameters\n");
CloseHandle(hSerial);
return 1;
}

// Set COM port timeout settings//
timeouts.ReadIntervalTimeout = 50;
timeouts.ReadTotalTimeoutConstant = 50;
timeouts.ReadTotalTimeoutMultiplier = 10;
timeouts.Wri

vinod b v 22-Apr-15 5:31am View

@ Richard MacCutchan I tried it but unfortunately the second part of the code does not run. I mean the i can only see F0 being displayed in my waveform and repeats continously

vinod b v 15-Apr-15 7:04am View

@Cpallini Accordingly at 200 baud i should get 25ms and 25ms high,when i measure i am not able to get the required wave i am getting like 10ms low and 40ms high.
But when i just send of at 200 baud without sending other part of the code. i am able to get it, but when i want to do it simultaneously i am failing.

vinod b v 15-Apr-15 6:01am View

I am supposed to get 25ms low and 25ms high square wave upon sending byte 0xF0 at 200 baud, and next my 5 databytes should be sent at 10400, but i am not able to see the exact waveform in my oscilloscope. is there something wrong in the code??

vinod b v 9-Apr-15 7:12am View

@ OriginalGriff Could you give me an example of how i do it in macro scale?

vinod b v 24-Mar-15 7:44am View

I want to first do a wakeup pattern before talking to ECU, so i am using fast intialisation which uses 10400bps, but if i send all data at once i dont find the required timing diagram in my oscilloscope.The requirement for KWP 2000 is as follows
It operates at 10400 Baud.
Initial state – Tidle .
Tlow for 25ms and Thigh for 25ms
Start communication request from Tester to ECU
Start communication response from ECU to Tester.
I am able to generate 25ms low and 25ms high, at 200bps. and when i change the baudrate at 10400 for rest of bytes it does behave strange. I tried i call a function for the second part.

vinod b v 24-Mar-15 6:30am View

i am using USB to serial Converter for OBD Diagnostics. And the problem occurs when i try to send the other set of bytes at higher baudrate, i am trying to intitialise with KWP2000 protocol

vinod b v 24-Mar-15 5:27am View

Dear Jochen Arndt, How do i make that the data arent on the line when changing baudrate. As per your advice i inserted another block the dcbSerialParams structure. but when i run all the data are overlapping. COuld you please help me on this issue.

vinod b v 23-Mar-15 11:22am View

Dear JOchen, is this write?

#include <windows.h>
#include <stdio.h>
#include <conio.h>

// INITIALISATION FOR 25MS LOW AND 25MS HIGH WITH PREDEFINED BAUDRATE OF 200 Bps,DATA 0XF0//

int main()
{
int _kbhit();
int _getch();
// Defining hexadecimal bytes to be sent a 200 bps//
int bytes_to_send[1];
bytes_to_send[0] = 0xF0;

// Bytes to be send at 10400 bps//
int databytes_send[5];
databytes_send[0] = 0x81;
databytes_send[1] = 0x11;
databytes_send[2] = 0xF1;
databytes_send[3] = 0x11;
databytes_send[4] = 0x04;

int GetPressedKey()
{
int ret = 0;
if (_kbhit())
{
ret = _getch();
}
return ret;
}

// Declare variables and structures//
HANDLE hSerial;
DCB dcbSerialParams = {0};
COMMTIMEOUTS timeouts = {0};

// Open the available serial port number//
fprintf(stderr, "Opening serial port...");
hSerial = CreateFile(
"COM3", GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );
if (hSerial == INVALID_HANDLE_VALUE)
{
fprintf(stderr, "Error\n");
return 1;
}
else
fprintf(stderr, "OK\n");

// Set device parameters (10400 baud, 1 start bit,
// 1 stop bit, no parity)
dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
if (GetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error getting device state\n");
CloseHandle(hSerial);
return 1;
}

dcbSerialParams.BaudRate = 200;
dcbSerialParams.ByteSize = 8;
dcbSerialParams.StopBits = ONESTOPBIT;
dcbSerialParams.Parity = NOPARITY;
if(SetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error setting device parameters\n");
CloseHandle(hSerial);
return 1;
}
// Calling DCB again //
dcbSerialParams.BaudRate = 10400;
dcbSerialParams.ByteSize = 8;
dcbSerialParams.StopBits = ONESTOPBIT;
dcbSerialParams.Parity = NOPARITY;
if(SetCommState(hSerial, &dcbSerialParams) == 0)
{
fprintf(stderr, "Error setting device parameters\n");
CloseHandle(hSerial);
return 1;
}

// Set COM port timeout settings
timeouts.ReadIntervalTimeout = 50;
timeouts.ReadTotalTimeoutConstant = 50;
timeouts.ReadTotalTimeoutMultiplier = 10;
timeouts.WriteTotalTimeoutConstant = 50;
timeouts.WriteTotalTimeoutMultiplier = 10;
if(SetCommTimeouts(hSerial, &timeouts) == 0)
{
fprintf(stderr, "Error setting timeouts\n");
CloseHandle(hSerial);
return 1;
}

// Send specified text (remaining command line arguments)
DWORD bytes_written, total_bytes_written = 0;
fprintf(stderr, "sending bytes...");

//fprintf("%d%%d%d%d%d",bytes_to_send[0],bytes_to_send[1],bytes_to_send[2],bytes_to_send[3],bytes_to_send[4]);//

while(1)
{

if (!WriteFile(hSerial, bytes_to_send, 1, &bytes_written, NULL))
break;
fprintf(stderr, "%d bytes written\n", bytes_written);
if (GetPressedKey())
break;
// Read data here

if (!WriteFile(hSerial, databytes_send, 5, &bytes_written, NULL))
break;
fprintf(stderr, "%d bytes written\n", bytes_written);
if (GetPressedKey())
break;

if (GetPressedKey())

break;
}

CloseHandle(hSerial);

if(!WriteFile(hSerial, databytes_send, 6, &bytes_written, NULL))
{
fprintf(stderr, "End of transmission\n");
CloseHandle(hSerial);
return 1;
}
fprintf(stderr, "%d bytes written\n", bytes_written);

// Close serial port
fprintf(stderr, "Closing serial port...");
if (CloseHandle(hSerial) == 0)
{
fprintf(stderr, "Error\n");
return 1;
}
fprintf(stderr, "OK\n");

// exit normally
return 0;
}

vinod b v 23-Mar-15 10:42am View

yes i shall do it, thank you.

vinod b v 23-Mar-15 10:37am View

Could you help me with this part of as n how can i call the Setcomm state, and send the bytes of data with different baud rate could you give me an example?

vinod b v 23-Mar-15 10:35am View

I am not understanding the way how to do it. first part of code works as i want, but once i send 1 byte of data at certain baudrate, later i need to change baudrate and send some more bytes of data to talk to ECU

vinod b v 23-Mar-15 10:32am View

for initialisation purpose

vinod b v 19-Mar-15 10:51am View

@ Jochen I could not follow what you meant? My main aim atlast is a GUI, but at first place i need to work on this part, sending bytes across the port and reading back and looping the data continously to observe the waveform with oscilloscope. ALthough not an expert at C.But i have created applications before with Labview.

vinod b v 19-Mar-15 6:39am View

When i use standard baud rate CBR_9600 or CBR_10400, it works fine but upon using CBR_10400 it gives me an error telling undeclared. Could you tell me whats wrong in setting a desired baud rate of my own as it is required for KWP 2000 Fast Initialization

vinod b v 18-Mar-15 11:57am View

I checked everything and i still dont know whats the error.
HANDLE hSerial; seems fine.

vinod b v 18-Mar-15 11:23am View

Yes i am using windows.h but still unsucessful.

vinod b v 18-Mar-15 10:52am View

Yes , thank you

vinod b v 18-Mar-15 10:39am View

No i did compile it as .CPP. And have used all the included the windows header file.

vinod b v 18-Mar-15 10:17am View

@jochen Arndt, yes i did, even this its giving these errors 5 and 12
error at 5. hSerial does not name a type.
error at 12. expected unqualified error before 'if'
5. HANDLE hSerial; // VARIABLE IS OF TYPE HANDLE AND INITILIZE WITH CALL TO CREATE FILE//
hSerial = createFile ("COM4",
GENERIC_READ | GENERIC_WRITE,
0,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
0);
12. if(hSerial==INVALID_HANDLE_VALUE)

vinod b v 18-Mar-15 10:08am View

I found out my system is using COM4, so i have changed it from COM1 to COM4, but still i get that error, and even did give entry like this:
HANDLE hSerial; // VARIABLE IS OF TYPE HANDLE AND INITILIZE WITH CALL TO CREATE FILE//
hSerial = createFile ("USB serial port(COM4)",
GENERIC_READ | GENERIC_WRITE,
0,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
0);
if(hSerial==INVALID_HANDLE_VALUE)
{
if(GetLastError()=ERROR_FILE_NOT_FOUND){
printf("//SERIAL PORT DOES NOT EXIST// ");
}
printf("//SOME OTHER ERROR OCCURED.//");
}

// SETTING PARAMETERS//

DCB dcbSerialParams = {0};
dcbSerial.DCBlength=Sizeof(dcbSerialParams);

if
(!GetCommState(hSerial, &dcbSerialParams))
{

// error getting state //
Printf("Error in getting state");
}
//SETTING PARAMETERS//
dcbSerialParams.BaudRate=CBR_9600;
dcbSerialParams.ByteSize=8;
dcbSerialParams.StopBits=ONESTOPBIT;
dcbSerialParams.Parity=NOPARITY;
if(!SetCommState(hSerial, &dcbSerialParams)){
//error setting serial port state
printf("Error");
}

//SETTING TIMEOUTS //

COMMTIMEOUTS timeouts={0};
timeouts.ReadIntervalTimeout=50;
timeouts.ReadTotalTimeoutConstant=50;
timeouts.ReadTotalTimeoutMultiplier=10;
timeouts.WriteTotalTimeoutConstant=50;
timeouts.WriteTotalTimeoutMultiplier=10;
if(!SetCommTimeouts(hSerial, &timeouts)){
//error occureed. Inform user
printf("Error occuring in timeouts");
}

char szBuff[n + 1] = {0};
DWORD dwBytesRead = 0;
if(!ReadFile(hSerial, szBuff, n, &dwBytesRead, NULL)){
//error occurred. Report to user.
printf("Error occured in read/write byte");
}
// Close handle //
CloseHandle(hSerial);

vinod b v 18-Mar-15 9:27am View

@ Jan Bakker, no i am using C language to write it although i am new to serial programming, I am using Codeblocks IDE

vinod b v 18-Mar-15 9:09am View

@ Jochen Arndt, i have a question here i am using code blocks IDE console application and when i write this piece of code i am getting error invalid handle
#include<windows.h>

// For opening serial port//
HANDLE hSerial;
hSerial = CreateFile("COM1",
GENERIC_READ | GENERIC_WRITE,
0,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
0);
if(hSerial==INVALID_HANDLE_VALUE){
if(GetLastError()==ERROR_FILE_NOT_FOUND){
//serial port does not exist. Inform user.
}

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