HM-WDS10-TH-O negative temp fix by fhem-hm-knecht

git-svn-id: https://fhem.svn.sourceforge.net/svnroot/fhem/trunk/fhem@1233 2b470e98-0d58-463d-a4d8-8e2adae1ed80

FHEM/10_CUL_HM.pm

@@ -662,8 +662,9 @@ CUL_HM_Parse($$)
 
     if($p =~ m/^(....)(..)$/) {
       my ($t, $h) = ($1, $2);
-      $t = hex($t)/10;
-      $t -= 3276.8 if($t > 1638.4);
+      $t = hex($t);
+      $t -= 32768 if($t > 16384);
+      $t = sprintf("%0.1f", $t/10);
       $h = hex($h);
       push @event, "state:T: $t H: $h";
       push @event, "temperature:$t";