--- cpr-m02.pl	2010/07/06 15:08:47	81
+++ cpr-m02.pl	2010/07/09 23:10:05	82
@@ -13,7 +13,7 @@
 
 use IO::Socket::INET;
 
-my $debug = 0;
+my $debug = 2;
 
 my $tags_data;
 my $tags_security;
@@ -155,9 +155,9 @@
 sub diag { _message('diag',@_) };
 
 my $device    = "/dev/ttyUSB0";
-my $baudrate  = "19200";
+my $baudrate  = "38400";
 my $databits  = "8";
-my $parity	  = "none";
+my $parity	  = "even";
 my $stopbits  = "1";
 my $handshake = "none";
 
@@ -264,6 +264,47 @@
 #$port->stty_inpck(1);
 #$port->stty_istrip(1);
 
+sub cpr_m02_checksum {
+	my $data = shift;
+
+	my $preset = 0xffff;
+	my $polynom = 0x8408;
+
+	my $crc = $preset;
+	foreach my $i ( 0 .. length($data) - 1 ) {
+		$crc ^= ord(substr($data,$i,1));
+		for my $j ( 0 .. 7 ) {
+			if ( $crc & 0x0001 ) {
+				$crc = ( $crc >> 1 ) ^ $polynom;
+			} else {
+				$crc = $crc >> 1;
+			}
+		}
+		warn sprintf('%d %04x', $i, $crc & 0xffff);
+	}
+
+	return pack('v', $crc);
+}
+
+sub cpr {
+	my $hex = shift;
+	my $bytes = str2bytes($hex);
+	my $len = pack( 'c', length( $bytes ) + 3 );
+	my $send = $len . $bytes;
+	my $checksum = cpr_m02_checksum($send);
+	$send .= $checksum;
+
+	warn ">> ", as_hex( $send );
+	writechunk( $send );
+	my $r_len = read_bytes( 1, 'response length' );
+	$r_len = ord($r_len) - 1;
+	my $data = read_bytes( $r_len, 'data' );
+	warn "<< ", as_hex( $data );
+}
+
+cpr( '00  52 00' );
+
+exit;
 # initial hand-shake with device
 
 cmd( 'D5 00  05   04 00 11                 8C66', 'hw version',
@@ -612,7 +653,7 @@
 	while ( length( $data ) < $len ) {
 		my ( $c, $b ) = $port->read(1);
 		die "no bytes on port: $!" unless defined $b;
-		#warn "## got $c bytes: ", as_hex($b), "\n";
+		warn "## got $c bytes: ", as_hex($b), "\n";
 		$data .= $b;
 	}
 	$desc ||= '?';