#!/usr/local/bin/perl
#
# This script gets the current temperatures from all specified probes
# on a "Hot Little Therm" and reports it to the console.
#
# By: Theo Van Dinter <tvd@chrysalis.com>
#

use strict;

my($hlt) = 1; # number of probes to check
my($device) = "ttyS0"; # which device (under /dev)?

my(%info)=( # information about specific probe IDs (location, etc.)
	   "10acbd2000000009" => "by einstein",
	   "105dcd2000000021" => "by toasters",
	   "104ec2200000004c" => "output ac",
	   "1058af2000000058" => "compressor output vent",
	   "1090cf2000000077" => "by yocto",
	   "100cbf20000000d6" => "intake ac",
	  );

# -- Do not edit below this line -- #

my(@temps) = ();

MAIN: {
  my($rin,$win,$ein,$num,$text);

  open(T,"+</dev/$device") || die "can't open /dev/$device:$!";
  select((select(T),$|=1)[0]); # non-buffered to device
  
  # get ready to do a select (polling -- boo!)
  $rin = $win = $ein = "";
  vec($rin, fileno(T), 1) = 1;
  $ein = $rin;
  
  for($num=0;$num < $hlt;$num++){ # run through all probes
    printf T "%c",16+$num; # probe on device $num
    
    do { # read in info from probe
      my($t)=select($rin,undef,$ein,3); # wait for data to be readable
      last if ( $t == -1 ); # end on error.
      next unless ( $t ); # skip if no data is readable
      
      sysread T, $text, 10, length($text); # add to end of text line.
    } until ( $text=~/Z\s*$/ ); # go until end of input.
  }
  close(T);
  @temps = ( $text =~ /\bT(\w{16} [+-]\d+\.\d+)\b/g );
}

PRINTING: {
  printf "\n%-16s Temperature     Information (if any)\n","Probe ID";
  print "-"x16," ","-"x15," ","-"x45,"\n";
  foreach ( @temps ) {
    tr/+-//d; # get rid of the +/- business

    my($probe,$tempc) = split /\s+/; # probe id and celsius temp.
    my($tempf) = ($tempc*9)/5+32; # Celsius -> Farenheit.
    my($tmp) = sprintf "%3.1fC = %3.1fF", $tempc, $tempf; # temp line

    # print me!
    printf "%-16s %-15s %-s\n",$probe,$tmp,$info{$probe};
  }
  print "\n";
}