Re: [Gumstix-users] Performing a serial timeout

[Ned F. <nfo...@wh...>]

ani...@pa... wrote:
> Hi All,
> 
> I want to perform a serial timeout read through my gumstix ttyS2  
> port.I use  normal read function but it
> gets stuck up when the controller at other end doesnot respond to it  
> or there is no physical connection between the two .
> 
> How can i give a read timeout option in C ?? I tried NON blocking  
> option also but then i am not able to get data .

It should be possible to open the port as non-blocking, and then perform
your own polling of the port for new data, presumably with a usleep()
somewhere in the loop so that your process does not hog the CPU.

However, the preferred way is to use either poll() or select(); either
one will wait for input from a specified group of ports (or any open
files) and will return after a specified timeout if no data are
available.  All the documentation is in the man pages.

-- 
Ned Forrester                                       nfo...@wh...
Oceanographic Systems Lab                                  508-289-2226
Applied Ocean Physics and Engineering Dept.
Woods Hole Oceanographic Institution          Woods Hole, MA 02543, USA
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