mirror of
https://github.com/fhem/fhem-mirror.git
synced 2024-11-22 09:49:50 +00:00
36 lines
976 B
Perl
Executable File
36 lines
976 B
Perl
Executable File
#!/usr/bin/perl
|
|
|
|
die("Usage: crc <HEX-MESSAGE> <CRC>\n") if(int(@ARGV) != 2);
|
|
my $msg = $ARGV[0];
|
|
$msg =~ s/ //g;
|
|
|
|
my $des = $ARGV[1];
|
|
$des =~ s/ //g;
|
|
|
|
# FFFF: 77 72 statt 2c 7f
|
|
# FFFF: 5C AC statt DC D9
|
|
|
|
|
|
#for(my $ic = 0; $ic < 65536; $ic++) {
|
|
for(my $ic = 0; $ic < 2; $ic++) {
|
|
my $crc = ($ic == 0?0:0xffffffff);
|
|
for(my $i = 0; $i < length($msg); $i += 2) {
|
|
my $n = ord(pack('H*', substr($msg, $i, 2)));
|
|
|
|
my $od = $n;
|
|
for my $b (0..7) {
|
|
my $crcbit = ($crc & 0x80000000) ? 1 : 0;
|
|
my $databit = ($n & 0x80) ? 1 : 0;
|
|
$crc <<= 1;
|
|
$n <<= 1;
|
|
$crc ^= 0x04C11DB7 if($crcbit != $databit);
|
|
# printf("%3d.%d %02x CRC %x ($crcbit $databit)\n", $i/2, $b, $n, $crc);
|
|
}
|
|
# printf("%3d %02x CRC %02x %02x\n", $i/2, $od, ($crc&0xff00)>>8, $crc&0xff);
|
|
}
|
|
# print "$ic\n" if($ic % 10000 == 0);
|
|
printf("%02x %02x\n",($crc&0xff00)>>8,$crc&0xff);
|
|
print "got $ic\n"
|
|
if(sprintf("%02x%02x",($crc&0xff00)>>8,$crc&0xff) eq $des);
|
|
}
|