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-rwxr-xr-xtools/beacon/decode.pl48
1 files changed, 48 insertions, 0 deletions
diff --git a/tools/beacon/decode.pl b/tools/beacon/decode.pl
new file mode 100755
index 0000000..28bf82b
--- /dev/null
+++ b/tools/beacon/decode.pl
@@ -0,0 +1,48 @@
+#!/usr/bin/perl -w
+
+use strict;
+use MIME::Base32 qw( RFC );
+
+my @beacons;
+if(!$ARGV[0] || $ARGV[0] eq "-") {
+ @beacons = <STDIN>;
+} else {
+ open(my $fh, "<", $ARGV[0]) or die "Unable to open file " . $ARGV[0];
+ @beacons = <$fh>;
+ close($fh)
+}
+
+foreach(@beacons) {
+ my $beacon = $_;
+ $beacon =~ s/\s*$//g;
+ $beacon =~ s/^\s*//g;
+
+ if($beacon =~ /([^ ]+) ([A-Z2-7]{3}) ([A-Z2-7])/) {
+ my $preamble = $1;
+ my $cnt = $2;
+ my $checksum = $3;
+
+ my $cntval = unpack("n", MIME::Base32::decode($cnt . "=")) >> 1;
+ my $csval_recv = unpack("C", MIME::Base32::decode($checksum . "=")) >> 3;
+
+ my $csval_calc = ord('N') - ord(' ');
+ my @values = unpack("C*", $preamble);
+ @values = (@values, unpack("C*", $cnt));
+ foreach(@values) { $csval_calc ^= $_ - ord(' '); }
+ $csval_calc = ($csval_calc & 0x1F) ^ (($csval_calc & 0x20) >> 5);
+
+ print $beacon . " -> cnt: " . $cntval;
+ if($csval_calc != $csval_recv) {
+ print " checksom wrong! (" . sprintf("%02X", $csval_recv) . " vs. " . sprintf("%02X", $csval_calc) . ")\n";
+ } else {
+ print " checksom ok! (" . sprintf("%02X", $csval_recv) . ")\n";
+ }
+
+
+ } else {
+ print $beacon . " -> Beacon format error!\n";
+ }
+
+
+}
+