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Serial.pm

#! C:\perl\bin\perl.exe

use strict;
use warnings;

package Serial;

# The following 2 lines I suspect are the lines that make a package into a module
# Also, they seem to make it a member of a class Exporter.

require Exporter;
my @ISA = qw( Exporter );  # This module "is a" Exporter class member

#Now declare what we permit to be visible within the module.
my @EXPORT = qw( &Serial_Init &Serial_TrxRcv );

use Win32::SerialPort;
use Time::HiRes qw(usleep);

my $port;

# ############ subroutine Serial_Init ###################################################

sub Serial_Init {

	my $port_name = 'COM5';
	#my $config_file = 'setup.cfg';    # use this to configure from the file

	$port = new Win32::SerialPort( $port_name ) 
	                ||  die "Unable to open: $^E\n";    # $^E EXTENDED_OS_ERROR
                                             
	#$port = new Win32::SerialPort($port_name, $config_file) || die "Unable to open: $^E\n";

	$port->handshake('none');     # none dtr rts xoff
	$port->baudrate(38400);       # 19200 57600 1200 9600 115200 4800 600 2400 300 38400
	$port->parity('none');        # space none odd even mark
	#$port->parity_enable(1); 	  #      for any parity except "none"
	$port->databits(8);           # options 7 8
	$port->stopbits(1);           # options 2 1
	$port->buffers(256, 256);
	$port->read_interval(0);      #RI
	$port->read_const_time(20);   #RC
	$port->write_char_time(1);    #WM
	$port->write_const_time(100); #WC

	print "Write settings;  ";

	$port->write_settings || undef $port;
	# A report out to the console
	my $baud   = $port->baudrate;
	my $parity = $port->parity;
	my $data   = $port->databits;
	my $stop   = $port->stopbits;
	my $hshake = $port->handshake;

	print "B = $baud, D = $data, S = $stop, P = $parity, H = $hshake\n\n";
            
	# use the below to save the current configuration
	# if ( $port ) { $port->save('setup.cfg') ; print "Serial Port OK \n" };

	# pack: used for assembling binary stuff
	# my $status = pack('H2' * 6, 'ca', '00', '01', '00', '00', 'fe');

	#$port->write("ati\x0D\x0A");      # carriage return and line feed:  no different
	#$port->write("ate0"."\r");	

	#print "test 01\n";
	#usleep 0;
	#print "test 02\n";
	
}

# ############## subroutine Serial_TrxRcv ###############################################

sub Serial_TrxRcv {
	
	my ($cmd) = @_;
	my $response = "";
	
	#print "cmd; $cmd\n";
	
	$port->write($cmd."\r");
	my $loop = 1;
	while( $loop ) {
		usleep(200000);         # 0.2 of a second
		my $partial_resp;
		$partial_resp = $port->input;
        chomp $partial_resp;    
		$response = $response.$partial_resp;
	   
	    # print $response;
	    
		#my $responseHex = unpack ('H*', $response);
		#print $responseHex."\n";
	     
	    my $last = substr ( $response, -1 );    # get the last character
	    if ($last eq ">") { $loop = 0; 
	    	                 $response = substr( $response, 0, -1);     # -1 removes the ">";
	    	                 chomp $response;
	    	                 next; 
	                      }
	    print ".";
	}
	
	return $response;	
	
}

1;
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