void
lcdCharDef(fd, index, data)
    int fd
    int index
    unsigned char * data
 
void
lcdPutchar(fd, data)
    int fd
    unsigned char data

##</code><code>##

extern void lcdCharDef(const int fd, int index, unsigned char data [8]);

extern void lcdPutchar(const int fd, unsigned char data);

##</code><code>##

sub lcd_char_def {
    shift if @_ == 4;
    my ($fd, $index, $data) = @_;
    my $unsigned_char = pack "V0C*", @$data;
    lcdCharDef($fd, $index, $unsigned_char);
}
sub lcd_put_char {
    shift if @_ == 3;
    my ($fd, $data) = @_;
    lcdPutchar($fd, $data);
}

##</code><code>##

#include <stdio.h>

#include <wiringPi.h>
#include <lcd.h>

int main (int argc, char *argv[]){

    unsigned char newChar [8] = {
        0b11111,
        0b10001,
        0b10001,
        0b10101,
        0b11111,
        0b10001,
        0b10001,
        0b11111,
    };

    wiringPiSetupGpio();

    static int fd;
    fd = lcdInit(2, 16, 4, 23, 16, 5, 6, 13, 19, 0, 0, 0, 0);

    lcdClear(fd);
    lcdPosition(fd, 0, 0);

    lcdCharDef(fd, 2, newChar);
    lcdPutchar(fd, 2);

    sleep(1);

    return 0;
}

##</code><code>##

use warnings;
use strict;

use WiringPi::API qw(:all);

setup_gpio();

my %args = (
    cols => 16,
    rows => 2,
    bits => 4,
    rs => 23,
    strb => 16,
    d0 => 5,
    d1 => 6,
    d2 => 13, 
    d3 => 19,
    d4 => 0,
    d5 => 0, 
    d6 => 0, 
    d7 => 0,
);

my $fd = lcd_init(%args);

my $def = [
  0b11111,
  0b10001,
  0b10001,
  0b10101,
  0b11111,
  0b10001,
  0b10001,
  0b11111,
];

lcd_clear($fd);
lcd_position($fd, 0, 0);

lcd_char_def($fd, 2, $def);
lcd_put_char($fd, 2);

sleep 1;