The circuit that you have used(the one from the lirc site) works on their
driver. Just had a glance at their
driver(/lirc-0.8.0/drivers/lirc_serial/lirc_serial.c). The comment says
explicitly :
*
* lirc_serial - Device driver that records pulse- and pause-lengths
* (space-lengths) between DDCD event on a serial port.
*
the read syscall, that you are trying to use in your user space pgm, on
/dev/ttys0 reads only data that are there on the registers related with pin
2(RXD). This is my idea, the dcd pin is basically for connecting devices like
modem's. To get a clear idea refer serial programming guide for POSIX
operating systems:
http://www.easysw.com/~mike/serial/serial.html#3_1_3
comming back to lirc_serial.c the driver from lirc.org, it is using the rdtsc
instruction to do its work(read that from comments).
from the around half an hour i spend on your problem i think the reception
mechanism is working not by reading some data, but by measuing pulse lengths on
the dcd. and that reading is originally being done by lirc_serial.c kernel
driver.
So for your user level program to work you nead to replicate that
functionality in your code.
Justin
thoma <arunthomas007 at gmail.com> wrote: Hi,
The project is to control a media player using a remote control. i can make
the media player. The problem is the receiver code.
i made a receiver as shown in the www.lirc.org website. The circuit diagram
is attached with this mail. i am using an LG remote control.
The whole thing is working using LIRC software. But i want to write my own
program and dont want to write a driver, since it is too hard.
So the program should be able to read data(signals) from the serial port.
The code i have written is as follows.
#include <stdio.h> /* Standard input/output definitions */
#include <
string.h> /* String function definitions */
#include <unistd.h>
/* UNIX standard function definitions */
#include <fcntl.h> /* File control definitions */
#include <errno.h> /* Error number definitions */
#include <termios.h>
/* POSIX terminal control definitions */
main()
{
//struct termios ts;
char buff[1000]=
"";
int fd;
int nbytes=0;
fd = open(
"/dev/ttyS0", O_RDONLY | O_NOCTTY | O_NDELAY);
if (fd == -1)
{
perror("open_port: Unable to open /dev/ttyS0 - "
);
}
else
{
write(1,"starting",8);
fcntl(fd, F_SETFL, 0);
nbytes=read(fd,buff,sizeof(buff));
write(1
,"\nThe signal from serial port is
\n
",33);
write(1,buff,nbytes);
write(
1,"\n",
1);
}
}
The program works with my serial mouse. But when i connect the receiver
circuit, it simply waits for the signals. i just want to get different signals
from different buttons in the remote.
Is there any other problem with the code. .
i tried python also. Still not getting any output.
hope u will reply soon.
Thank You,
Arun Thomas
Model Engineering College
Cochin - Show quoted text -
On 3/20/06, Raj Shaz <rajshas at gmail.com> wrote: well im not sure wot do u
mean by open("/dev/ttyS0", O_RDONLY)
which is these codes?
See, serial programming can be done in trillion ways. Everone will
tell his/her own views` ... take one and chuck others ... but all lead
more or less in same way.
anyway i prefer python . since it work as if ur working on a file ...
open read/write close. simple... and libraries are good.
google ull get ans.
-raj
On 3/19/06, justin joseph < justin_joseph007 at yahoo.com> wrote:
>
>
> --- thoma <arunthomas007 at gmail.com> wrote:
>
> > Hi,
> >
> >
> > i used
> > open("/dev/ttyS0", O_RDONLY)
> > method. but i am not able to receive the signals.
> > But if my serial mouse is connected, i can read from
> > ttyS0.
> > is there any other method
>
> You can use inb, outb combination to read and write
> from the serial port. I think that will give you more
> control over the port. The below link might give you
> some idea.
>
> http://linuxgazette.net/issue99/misc/pramode/recv.txt
>
>
> > proper device driver for
> > the serial port.
> > Plz help me. Its urgent
> > > _______________________________________________
> > Mailinglist mailing list
_______________________________________________
Mailinglist mailing list
Mailinglist at ilug-cochin.org
http://ilug-cochin.org/mailman/listinfo/mailinglist_ilug-cochin.org
---------------------------------
Yahoo! Mail
Use Photomail to share photos without annoying attachments.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://ilug-cochin.org/pipermail/mailinglist_ilug-cochin.org/attachments/20060321/c428e58b/attachment.htm
