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problem with beagle board serial port

vishal gosai — Thu, 26 Jan 2012 05:35:28 +0100

problem with serial port

I am currently working with the beagle board in which Linux is ported. I have written program in it so that It continuously reads the data coming to the serial port.I send the requests(at every 1 second) to it by modbus tester(In another PC) but when it reads the requests, immediately it(beagleboard) sends the garbage bytes to the serial port.I don't write to the serial port or nothing at all do to write anything to the serial port(in beagle board) still it writes immediately after reading the requests.
I have attached a piece of code at beagle board side..(assuming all necessary declaration)

int main()
{
int num_read,i,j,l;
char read_buffer[11];
char *nums_read = &read_buffer;
char nums[] = {0x02,0x04,0x00,0x00,0x00,0x02,0x71,0xf8};
char *nums_write = &nums;

serial_port_open();

while(1)
{

signal (SIGINT, (void*)sigint_handler);

tcflush(serial_port,TCIOFLUSH);

// The main program loop:

for(l=0;l<10;l++)
{ for(i=0;i<65535;i++)
{

if (serial_port != -1)
{

num_read = serial_port_read(nums_read, 9);

if (num_read > 0)
{
goto pa;
}

}

}
}
pa:j=1;

}
}

int serial_port_open(void)
{
struct termios options;

serial_port = open(PORT_NAME, O_RDWR | O_NONBLOCK);

if (serial_port != -1)
{
printf("Serial Port open\n");
tcgetattr(serial_port,&options_original);
tcgetattr(serial_port, &options);
cfsetispeed(&options, B9600);
cfsetospeed(&options, B9600);
options.c_cflag |= (CLOCAL | CREAD);
options.c_lflag |= ICANON;
tcsetattr(serial_port, TCSANOW, &options);
}
else
printf("Unable to open /dev/ttyS2\n");
return (serial_port);
}

int serial_port_read(char *nums_read, size_t max_chars_to_read)
{
int i,l;

int chars_read = read(serial_port, nums_read, max_chars_to_read);

usleep(20000);
tcflush(serial_port,TCIOFLUSH);

return chars_read;
}

A part of the observation of free serial monitor is written here.Request is issued by the modbus tester and answer(undesired) is given by beagleboard.I don't know how it writes into the serial port...please help me work out this problem as soon as possible...

Request:
01 01 00 00 00 64 3D E1 01 01 00 00 00 64 3D E1 01 01 00 00 00 64 3D E1

Answer:
5E 41

Request:
01 01 00 00 00 64 3D E1 01 01 00 00 00 64 3D E1 01 01 00 00 00 64 3D E1 01 01 00 00 00 64 3D E1

Answer:
5E 41

Request:
01 01 00 00 00 64 3D E1

Answer:
5E 41

..........

Posted to: problem with beagle board serial port

Re: Booting beagleboard

Antonio Rodulfo — Sun, 22 Jan 2012 02:53:04 +0100

In order to be a little more helpful, I'd need to know a little more about what you have in hands.
You can start with the type of BB you have, what distro you selected amongst the many ones available.

Out of what you have posted, I see you have successfully come across the process of downloading and installing a distro in the SD. In case you didn't miss anything, what you're looking at is the opening of a simple terminal emulation program called "minicom", freely available for download but not usually found in BB distros.

As I said, I need some more info to help.

Posted to: Booting beagleboard

Re: Beagle board beginner

Antonio Rodulfo — Sun, 22 Jan 2012 02:44:26 +0100

Kerstin pointed at the first stop for you, no doubt.
You can go to that web and find a lot of help.
On the other hand, based on my small exprerience with the BB, I'm sure you can do much more than simple applications; as per the old joke, only the sky's the limit. You just follow your imagination.

Good luck!

Posted to: Beagle board beginner

Re: Is this site still up to date?

Kerstin Balka — Tue, 03 Jan 2012 12:56:21 +0100

Activity has been a little lower recently. However the list is still mostly up to date. If you are missing anything or if things have changed, feel free to update ;-)

Cheers
Kerba

Posted to: Is this site still up to date?

Is this site still up to date?

bram geenen — Mon, 02 Jan 2012 12:27:30 +0100

I was wondering if this list of open projects is still up to date? It looks like there is little activity on the website.
Is there another website that keeps a list of open projects?

Posted to: Is this site still up to date?

Re: Is posting our project on this site sufficient...

Kerstin Balka — Sun, 18 Dec 2011 15:06:45 +0100

Depends on how you define Open Source...

If you want your project to be Open Source from a legal perspective, you should use an open license, e.g., through Creative Commons. Thereby you can also protect it from being used in closed source context by someone else, if you want to.

Independent of the legal perspective, I would define a project as Open Source, as soon as you share knowledge and/or allow contributions by others. In this regard posting it on this site is a first step, but not sufficient, as you cannot reveal specific knowledge here.

Cheers
Kerba

Posted to: Is posting our project on this site sufficient...

Re: Is posting our project on this site sufficient...

Fred Frazelle — Thu, 13 Oct 2011 20:49:51 +0200

How interesting... 2,800 views and no reply. Hmmm...

Have a great morning! :)

Posted to: Is posting our project on this site sufficient...

Porting DVSDK 4.01 on Beagleboard-xM Rev B/C

Naveen Kumar — Mon, 10 Oct 2011 19:05:47 +0200

Hello to all,

We have ported DVSDK-4.01 onto Beagleboard-xM Rev B/C and uploaded the Source file in Sourceforge,

For more details please go through the link provided below,

http://sourceforge.net/projects/dvsdkbbxm/files/DVSDK-4.01%20for%20BeagleBoard/

Thank-you.

Posted to: Porting DVSDK 4.01 on Beagleboard-xM Rev B/C

Is posting our project on this site sufficient...

Fred Frazelle — Wed, 14 Sep 2011 21:48:38 +0200

to insure that it falls under OpenSource? We have started a project here called SolarProjects and our first one has to do with concentrated solar hot water and we wish it to be OpenSource. However obviously not all components are OS - such as the tracker circuit, the dome for the tracker circuit, etc.

So, would posting what we have done on this site be sufficient to allow whatever knowledge we have been able to add to this topic/product to be of the OS type?

Have a great afternoon! :)

Posted to: Is posting our project on this site sufficient...

Porting customised linux on beagle board xm

Raghav T — Tue, 01 Feb 2011 18:32:08 +0100

Hi all,

I have purchased beagle board xm and I want to port customised linux kernel on it.From the files in sd card which was there with beagle board, I took mlo,u-boot.bin,user.scr files and with those files I got bootloader on the board.Can anyone here please help how to port custom linux kernel.

Thanks,
Raghavendra

Posted to: Porting customised linux on beagle board xm