[ruby-talk:16700] Re: Serial Communications

In message <Pine.LNX.3.96.1010620145151.18092A-100000@relayer>
[e-mail] writes:

> Well, you'd only need to go back for a few pages of C. However it's better
> to know <termios.h> beforehand, and know some of the Ruby<->C bridge.
> 
> After that you'll have to make decisions, like how struct termios maps to
> Termios objects: copy upon crossing C/Ruby limit; or make Termios wrap
> struct termios; or just don't make a Termios object, and handle everything
> through methods...

FYI there's already termios extension library by Akira YAMADA
<http://arika.org/pub/Tools/Ruby/ruby-termios-module-0.0.4.tar.gz>.

# I'm not sure but it is already imported into CVS repository.... Ugh,
# I forgot the name of the module, sorry.


That is a straightforward wrapper of the POSIX termios interface.  See
attatched example which is included the tarball.


-- 
[e-mail]                                  June 21, 2001
Shortest way may be longest way.

require 'termios'

DEVICE = '/dev/ttyS3'
BAUDRATE = Termios::B38400


RESCUE = Termios::new_termios(1280, 5, 3261, 35387, 
			      [3, 28, 127, 21, 4, 0, 1, 0, 17, 
				19, 26, 0, 18, 15, 23, 22, 0, 0, 
				115, 80, 138, 6, 8, 48, 236, 
				255, 191, 85, 97, 0, 64, 3], 13, 13)
#p 1
dev = open(DEVICE, 'r+')
#p 1
#sleep 30
#p Termios::getattr(dev)
#Termios::setattr(dev, Termios::TCSANOW, RESCUE)
#p Termios::getattr(dev)
#p 1
#exit

oldtio = Termios::getattr(dev)
p oldtio

newtio = Termios::new_termios()
newtio.c_iflag = Termios::IGNPAR
newtio.c_oflag = 0
newtio.c_cflag = (BAUDRATE | Termios::CRTSCTS | 
		  Termios::CS8 | Termios::CREAD)
newtio.c_lflag = 0
newtio.c_cc[Termios::VTIME] = 0
newtio.c_cc[Termios::VMIN]  = 1

Termios::flush(dev, Termios::TCIOFLUSH)

Termios::setattr(dev, Termios::TCSANOW, newtio)
p Termios::getattr(dev)

"AT\x0d\x0a".each_byte {|c|
  c = c.chr
  dev.putc c
  d = dev.getc.chr
  p [c, d]
}

i = ''
while /OK\x0d\x0a/o !~ i
  i << dev.getc.chr
  p i
end

Termios::setattr(dev, Termios::TCSANOW, oldtio)
p Termios::getattr(dev)