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<H2>HiPi::Interface::HTBackpackV2</H2><p>HiPi::Interface::HTBackpackV2 provides an implementation of <A HREF="mod_interface_hd44780.htm">HiPi::Interface::HD44780</A> for LCD devices using the HobbyTronics Backpack V2 controller.</p>
<p>The module inherits many of its methods from <A HREF="mod_interface_hd44780.htm">HiPi::Interface::HD44780</A>.</p>
<h2>Object Constructor and Methods</h2>
<pre>
This module exports the following constants on request for use with
the inherited 'update_baudrate' method.
use HiPi::Interface::HTBackpackV2 qw( :htv2baud );
# exports constants
HTV2_BAUD_2400
HTV2_BAUD_4800
HTV2_BAUD_9600
HTV2_BAUD_14400
HTV2_BAUD_19200
HTV2_BAUD_28800
HTV2_BAUD_57600
HTV2_BAUD_115200
The following are the methods specific to this implementation.
See <A HREF="mod_interface_hd44780.htm">HiPi::Interface::HD44780</A> for inherited methods.
</pre>
<h5>my $lcd = HiPi::Interface::HTBackpackV2->new( %params );</h5>
<pre> %params contains a number of key value pairs
Required key value pairs
width => $width
lines => $lines
You must specify the geometry of your LCD
e.g.
my $lcd = HiPi::Interface::HTBackpackV2->new(
width => 16,
lines => 4,
);
Optional params and their defaults
backlightcontrol => 0
specify if methods setting the level of backlight can be used.
The method $lcd->backlight will only work if you set
backlightcontrol => 1 in the constructor.
devicetype => 'serialrx'
The Backpack supports two connection types, 'serialrx' and 'i2c'
You can specify either - the default is 'serialrx'
Options and their defaults when devicetype is 'serialrx'
devicename => '/dev/ttyAMA0'
baudrate => 9600
parity => 'none',
stopbits => 1,
databits => 8,
Options and their defaults when devicetype is 'i2c'
devicename => ( raspbi board version == 1 )
? '/dev/i2c-0' : '/dev/i2c-1'
address => 0x3A
Example complete constructor calls:
my $lcd = HiPi::Interface::HTBackpackV2->new(
width => 16,
lines => 4,
devicetype => 'serialrx',
backlightcontrol => 1
);
my $lcd = HiPi::Interface::HTBackpackV2->new(
width => 16,
lines => 4,
devicetype => 'i2c',
address => 0x3A
backlightcontrol => 1
);</pre>
<h5>$lcd->change_i2c_address( $newaddress );</h5>
<pre> Change the I2C address if using in i2c mode.
The i2c address must be in the range 1 - 127 ( 0x01 - 0x7F )</pre>
<h5>$lcd->send_htv2_command( $command, @params );</h5>
<pre> You can use the HobbyTronics Backpack documented commands directly
if you wish. The $command param is the backpack command number
and you can follow this with any number of parameters required.
This module exports the following constants on request for use with
the the send_htv2_command '$command' parameter.
use HiPi::Interface::HTBackpackV2 qw( :htv2cmd );
HTV2_CMD_PRINT
HTV2_CMD_SET_CURSOR_POS
HTV2_CMD_CLEAR_LINE
HTV2_CMD_CLEAR_DISPLAY
HTV2_CMD_LCD_TYPE
HTV2_CMD_HD44780_CMD
HTV2_CMD_BACKLIGHT
HTV2_CMD_WRITE_CHAR
HTV2_CMD_I2C_ADDRESS
HTV2_CMD_BAUD_RATE
HTV2_CMD_CUSTOM_CHAR
</pre>
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