#!/usr/bin/perl

# script for smarttemp3a

# for smarttemp3a details, see

	# http://www.kolumbus/probyte/temp.htm
	

# Author: Paavo Leinonen (paavo.leinonen@wipsl.com)
# pieniä muutoksi P.Ritamaki 20.8.2003
# use strict;
use warnings;
use diagnostics;

$SIG{HUP}=sub{$interrupted=1}; # signal handlers
$SIG{INT}=sub{$interrupted=1};
$SIG{USR1}=sub{$interrupted=1};
$SIG{USR2}=sub{$interrupted=1};
$SIG{TERM}=sub{$interrupted=1};

# configurable values

$port="/dev/ttyS4"; # the serial port we want
$lockfile="/var/lock/LCK..ttyS4"; # lockfile for $port
$mode=2; # open for reading and writing
$max=512; # just big enough number for buffer/read size
$sleeptime=1; # time to sleep between reading different lines
$sleeptime_between_loops=7; # can you read?

$exit_value=0; # clean exit value, 0 if no errors
# error values:
$error_1st_bit=1; # serial port close fails
$error_2nd_bit=2; # lock file removal fails
# no assignments yet:
# $error_3rd_bit=4;
# $error_4th_bit=8;
# $error_5th_bit=16;
# $error_6th_bit=32;
# $error_7th_bit=64;
# $error_8th_bit=128;


# smarttemp3a initialisation string is (63 bytes, last two CR/LF?):
# "sm3a $TT00C00=000 $TT00C01=000 $TT00C02=000 +22.0  $TT00+22.0  "

$cal_read_line_0_first_byte=14; # see previous comment line
$cal_read_line_1_first_byte=27;
$cal_read_line_2_first_byte=40;
$cal_read_value_length=3;

# starttemp3a temperature readings are in format (12 bytes each):
# "$TT00+22.0  " "$TT01+26.2  " "$TT02+41.6  " (last two: CR/LF?)

$temp_read_first_byte=5; # see previous comment line
$temp_read_val_length=5;

$title="Perl serial port test version";
$author="- PTL -";
$editdate="15-Jan-2001";

$line_0_name="Temp1"; # wharever: Indoors, Outdoors, Sauna, etc.
$line_1_name="Temp2";
$line_2_name="Temp3";

$our_speed="2400"; # smarttemp3a want this
$orig_speed="9600"; # this is the original in my system

$interrupted=0; # to ensure it has a value

# now, lets do it

print("$title $author $editdate\n");

$ENV{PATH}="/bin:/usr/bin"; # make path secure
delete @ENV{qw(IFS CDPATH ENV BASH_ENV)}; # get rid of these, not needed

if(-e $lockfile) # is the lockfile there already?
{
	die("Lockfile $lockfile already exists");
}

system("touch $lockfile"); # create lockfile
$login = getpwuid($>); # who am I?
system("echo '     ' $$ `basename $0` $login > $lockfile"); # write info

unless(-e $lockfile) # is the lockfile there now?
{
	die("Could not create lockfile $lockfile");
}

system("stty -F $port $our_speed"); # set up serial port parameters first
system("stty -F $port ignbrk -icrnl"); # these values seem to work
system("stty -F $port -opost -onlcr");
system("stty -F $port -isig -icanon");
system("stty -F $port -iexten -echo");
system("stty -F $port -echoe -echok");
system("stty -F $port -echoctl -echoke");

sleep($sleeptime); # wait a sec, lets not hurry...

$ret=sysopen($serial,$port,$mode) or die("Cannot open $port");
print("Serial port $port opened\n\n");
sleep($sleeptime); # wait a sec again, lets not hurry...

# this is the first read, it includes the calibration values

$ret=sysread($serial,$buf,$max); # read the init string

print("Calibration values are:\n\n\t$line_0_name: ");
print(substr($buf,$cal_read_line_0_first_byte,$cal_read_value_length));
print("\n\t$line_1_name: ");
print(substr($buf,$cal_read_line_1_first_byte,$cal_read_value_length));
print("\n\t$line_2_name: ");
print(substr($buf,$cal_read_line_2_first_byte,$cal_read_value_length));
print("\n\n");

sleep($sleeptime); # sleep a bit before looping

$count=0; # count how many loops we do

do
{
	($sec,$min,$hour,$mday,$mon,$year,$wday,$yday)=localtime(time);
	$year+=1900; # $year is the number of years since 1900
	$mon+=1; # $mon is in the range 0..11 with 0 indicating January
	$mon=sprintf("%02d",$mon); # ensure 2 digits
	$mday=sprintf("%02d",$mday); # ensure 2 digits
	$hour=sprintf("%02d",$hour); # ensure 2 digits
	$min=sprintf("%02d",$min); # ensure 2 digits
	$sec=sprintf("%02d",$sec); # ensure 2 digits
	print("$mday.$mon.$year $hour:$min:$sec"); # print date and time

	$wday=0; # get rid of unnecessary warnings
	$yday=0; # get rid of unnecessary warnings

	$buf="#TT00"; # first one
	$ret=syswrite($serial,$buf,length($buf));
	sleep($sleeptime); # dont be too fast, serial line has not flow control

	$ret=sysread($serial,$buf,$max);
	$buf=substr($buf,$temp_read_first_byte,$temp_read_val_length);
	print(" $line_0_name $buf");

	$buf="#TT01"; # second one
	$ret=syswrite($serial,$buf,length($buf));
	sleep($sleeptime); # dont be too fast, serial line has not flow control

	$ret=sysread($serial,$buf,$max);
	$buf=substr($buf,$temp_read_first_byte,$temp_read_val_length);
	print(" $line_1_name $buf");

	$buf="#TT02"; # third one
	$ret=syswrite($serial,$buf,length($buf));
	sleep($sleeptime); # dont be too fast, serial line has not flow control

	$ret=sysread($serial,$buf,$max);
	$buf=substr($buf,$temp_read_first_byte,$temp_read_val_length);
	print(" $line_2_name $buf");

	print(" (sleeping $sleeptime_between_loops seconds...)\n");
	$count++; # one loop done
	unless($interrupted)
	{
		sleep($sleeptime_between_loops); # only sleep if not interrupted
	}
} until $interrupted; # continue until a ctrl-c is pressed or TERM signal

# done

unless(close($serial)) # close serial port
{
	print("Could not close $port\n");
	$exit_value+=$error_1st_bit; # increment exit value
}

system("stty -F $port $orig_speed"); # restore original settings in RH7.0
system("stty -F $port -ignbrk icrnl"); # for AST 4 Port serial card
system("stty -F $port opost onlcr");
system("stty -F $port isig icanon");
system("stty -F $port iexten echo");
system("stty -F $port echoe echok");
system("stty -F $port echoctl echoke");

system("rm -f $lockfile"); # remove lockfile

if(-e $lockfile) # is the lockfile still there?
{
	print("Could not remove lockfile $lockfile\n");
	$exit_value+=$error_2nd_bit; # increment exit value
}

print("\nWe did $count loops - thank you, goodbye, and see you again! -PTL\n");

exit($exit_value); # exit value is 0 if there were no errors