1 files changed, 5 insertions, 3 deletions

diff --git a/scd4x b/scd4x
index 65cdf52..aae5919 100755
--- a/scd4x
+++ b/scd4x
@@ -12,6 +12,10 @@ my $host = shift;
 my $json = JSON->new->allow_nonref;
 my $mqtt;
 
+my $values;
+my $pvalues;
+my $serial;
+
 sub read_json_file {
 	my $filename = shift;
 	my $content;
@@ -27,11 +31,9 @@ if (defined($host)) {
 	$mqtt = Net::MQTT::Simple->new($host) or die "mqtt init (server $host)"
 }
 
-my $values;
-my $pvalues;
 for (;;) {
 	$values = read_json_file($file);
-	my $serial = $values->{'serial'};
+	$serial = $values->{'serial'};
 	for my $key ('co2', 'temperature', 'humidity') {
 		next if defined($pvalues->{$key}) and $pvalues->{$key} eq $values->{$key};
 		my $topic = "sensors/" . $key . "/scd4x/" . $serial;