+sub inventory {
+
+ my $inventory;
+
+cmd( 'FE 00 05', 'scan for tags', sub {
+ my $data = shift;
+ my $rest = assert $data => 'FE 00 00 05';
+ my $nr = ord( substr( $rest, 0, 1 ) );
+
+ if ( ! $nr ) {
+ warn "# no tags in range\n";
+ } else {
+ my $tags = substr( $rest, 1 );
+ my $tl = length( $tags );
+ die "wrong length $tl for $nr tags: ",dump( $tags ) if $tl =! $nr * 8;
+
+ foreach ( 0 .. $nr - 1 ) {
+ my $tag = uc(unpack('H16', substr($tags, $_ * 8, 8)));
+ $invetory->{$tag}++;
+ }
+ }
+
+});
+
+ return $invetory;
+}
+