How to interface LCM1602C LCD with ATmega16?

Using Arduino Displays
1

I have LCM1602C LCD which I got with Arduino Starter Kit.I want to Interface it with ATmega16.But no matter what I do LCD just doesn't print anything.Just to check if the LCD is in working condition I connected it to Arduino and uploaded example project and it seems to work just fine.As the code was not working I also tried to run it on Proteus and it ran perfectly just one difference and that is LCM1602C was not available so I used LM016L LCD as both have similar pin configuration. The code I am trying to run on ATmega 16 is as follows:

#include <avr/io.h>
#include <util/delay.h>

#define RS 6
#define E  7

void send_a_command (unsigned char command);
void send_a_character(unsigned char character);

int main(void)
{
    _delay_ms(5000);
    DDRC = 0xFF;
    DDRD = 0xFF;
    _delay_ms(50);
    send_a_command(0x01);// sending all clear command
    send_a_command(0x38);// 16*2 line LCD
    send_a_command(0x0F);// screen and cursor blink

    send_a_character (0x44); 
    send_a_character (0x44); 
    send_a_character (0x44); 
    send_a_character (0x44); 
    send_a_character (0x44); 
    send_a_character (0x44); 
    send_a_character (0x44); 
    send_a_character (0x44); 
    while(1);
}

void send_a_command (unsigned char command)
{
    PORTC=command;
    PORTD&= ~(1<<RS);
    PORTD|= (1<<E);
    _delay_ms(50);
    PORTD&= ~(1<<E);
    PORTC = 0;
}

void send_a_character (unsigned char character)
{
    PORTC=character;
    PORTD|= (1<<RS);
    PORTD|= (1<<E);
    _delay_ms(50);
    PORTD&= ~(1<<E);
    PORTC =0;
}

Image from Proteus simulation:

1016×631 11.5 KB

Note: the initial 5000 ms delay was given because I thought LCD might be missing the starting instructions just after power on.The code doesn't run even after removing that statement.

I tried to search for LCM1602C datasheet but had no luck finding one. So is there some other command instruction set for LCM1602C?