allow only meaningful readings (fill level > -5%) in USF1000

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@633 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/CHANGED

@@ -577,7 +577,7 @@
   	     (Gerhard Pfeffer / MartinH)
   - feature: pgm2 style changes, SVG in background, optional compression
 
-- =DATE= (5.0)
+- =DATE= (4.10)
   - feature: KM271: Read only
   - bugfix:  99_SUNRISE_EL endless loop bug
   - feature: CUL: optional baudrate spec in definition
@@ -587,3 +587,4 @@
   - feature: FHEMWEB javascript additions for SVG plots (click on lines/labels)
   - feature: FHEMWEB smallscreen attribute
   - feature: Dimmer function of X10 module changed to match FS20 dimmer functions.
+  - feature: allow only meaningful readings (fill level > -5%) in USF1000

fhem/FHEM/09_USF1000.pm

@@ -137,6 +137,9 @@ USF1000_Parse($$)
   	$flevel  = int($volume/$capacity*100.0+0.5);
   	$volume= int($volume/10.0+0.5)*10.0;
 
+  	if($flevel>-5) {
+		# reflections may lead to false reading (distance too large)
+		# the meaningless results are suppressed
 
 		my $state= sprintf("v: %d  V: %d", $flevel, $volume);
 
@@ -153,6 +156,7 @@ USF1000_Parse($$)
 		$def->{READINGS}{volume}{TIME} = $t;
 		$def->{READINGS}{volume}{VAL} = $volume;
 	}
+  }
 
   my $warnings= ($lowbattery ? "Battery low" : "");
   if($testmode) {