[misterhouse-users] DS2405 1-wire code

[J & K U <up...@ea...>]

Neil Wrightson,

A buddy of mine and I are using the 1-wire interface for lot's o' stuff.  At
least we plan to.  He has developed hardware based on the DS2405 that will
open and close a greenhouse roof window, and will control a heater as well.
The temperature will be sensed with a DS1920.  The smarts of the operation
will be misterhouse, using the following modifications to the Device.pm
modules (I think I mis-spoke when I said there were changes to
Connection.pm):

Add the following to the models section:
#########################################################################
         "05" => {			# Jon Upham
                 'model' => 'DS2405',
                 'memsize' => 0,
                 'memtype' => "none",
                 'specialfuncs' => "pio",
                 'class' => 'Hardware::iButton::Device::DS2405'
               },

Add the following below in the package Hardware::iButton::Device section,
(I put it between sub family and sub serial)...:
#########################################################################
sub raw_id { # Added by Jon Upham
    return $_[0]->{'raw_id'};
}

Add the following below in the packages section:
#########################################################################
package Hardware::iButton::Device::DS2405;

use Hardware::iButton::Connection;

# This code supports using the DS2405's native functions: toggling and
reading the state
# See the data sheet for more information on this device.  Implemented here
by Jon Upham.

use strict;
use vars qw(@ISA);

@ISA = qw(Hardware::iButton::Device);

=head2 toggle2405

Use this like other 1-wire devices in this module.

=cut
sub toggle2405{
    my $this = shift;
    my $serial = pack( "b*", $this->raw_id() );
    my $c = $this->{'connection'};
    my $send;

    # reset the 1-wire
    if ($this->reset()) {
	# create a buffer to use with block function
	# match Serial Number command 0x55
	$send .= "\x55";

	# Serial Number
	$send .= $serial;

      $send .= "\xFF"; # Added to send enough bits to read the return from
the 2405

	# send/recieve the transfer buffer
	my $result = $c->owBlock( $send );

#print "Sent:  ".unpack("b*",$send)."\n";
#print "Result:".unpack("b*",$result)."\n";

      # now get the last bit of the unpacked result and that's the state!
      my $rv = unpack("b*",$result);
      my $state2405 = substr($rv,length($rv)-1,1);
#print "State: $state2405\n";
	return $state2405
    }

    # reset or match echo failed
    return -1;
}
=head2 query2405

Use this like other 1-wire devices in this module.
This code should look familiar to the FindDevices code in Connection.pm

=cut
sub query2405{
    my $this = shift;
    my $serial = pack( "b*", $this->raw_id() );
    my $c = $this->{'connection'};

	my @tmpSerial = split //, unpack( "b*", $serial );
	my $send;

	# construct the search rom
	$send .= "\xF0";

	my @tmpSend = ( 1 ) x (24 * 8);

	# now set or clear apropriate bits for search
	foreach my $i ( 0..63 ) {
	    $tmpSend[3*($i+1)-1] = $tmpSerial[$i];
	}

	$send .= pack( "b*", join( "", @tmpSend ) );

	#Add a /xFF so that we'll receive the status of the 2405 back

	$send .= "\xFF";

	# send/recieve the transfer buffer
	$this->reset();
	my $result = $c->owBlock( $send );
	if ( $result ) {
	    # check results to see if it was a success
	    my @result = split //, unpack( "b*", substr( $result, 1 ) );
	    my $cnt = 0;
	    my $goodbits = 0;
	    for (my $i = 0; $i < 192; $i += 3) {
		my $tst = ( $result[$i] << 1 ) | $result[$i+1];
		my $s = $tmpSerial[$cnt++];

		if ($tst == 0x03) {
		    # no device on line
		    $goodbits = 0;    # number of good bits set to zero
		    last;     # quit
		}

		if ( ( $s == 0x01 && $tst == 0x02 ) ||
		     ( $s == 0x00 && $tst == 0x01 ) ) {
		    # correct bit
		    $goodbits++;  # count as a good bit
		}
	    }

	    # check too see if there were enough good bits to be successful
      if ($goodbits >=8){
         my $rv = unpack("b*",$result);
         my $state2405 = substr($rv,length($rv)-1,1);
         print "State: $state2405\n";
	   return $state2405
      }
	    return ( -1) if $goodbits >= 8;
	}

	# block fail or device not present

print "problem sending reset...\n";

	return (-2);

}
#########################################################################

Please let me know if this doesn't work.  I didn't take a lot of time to
clean it up.  Note that a lot of the code may "look familiar".  I believe in
recycling code!

Cheers,
Jon Upham