I am trying to display "hello world" on the jhd 162a lcd using
ATMEGA 16A. I am writing the attached code in winavr but on compiling it is giving the error. lcd is connected with the microcontroller in 4 bit mode.
connection diagram is--------------

PB 7: Data 7
PB 6: Data 6
PB 5: Data 5
PB 4: Data 4
PB 3: N/A
PB 2: Enable
PB 1: R/W
PB 0: Register Select

even the cursor is not displaying on the lcd................


the code is

"#include <avr/io.h>
#include <stdlib.h>
#include <util/delay.h>
#include <stdio.h>

//Define functions
//==========================================================
void io_init(void); //Initializes IO
void send_nibble(unsigned char __rs, unsigned char __data);

//==========================================================

int main (void)
{
//io_init();
DDRB =0b11101111;
PORTB = 0b01111111;
delay_ms(10);
PORTB = 0b00100010; // xsending command
delay_ms(10);
PORTB = 0b00000010;
delay_ms(10);
PORTB = 0b00101000; // xsending command
delay_ms(10);
PORTB = 0b00001000;
delay_ms(10);
PORTB = 0b10100100; // xsending data ‘H’
delay_ms(10);
PORTB = 0b10000100;
delay_ms(10);
PORTB = 0b10101000; // sending data
delay_ms(10);
PORTB = 0b10001000;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘E’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10100101; // sending data
delay_ms(10);
PORTB= 0b10000101;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘L’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10101100; // sending data
delay_ms(10);
PORTB= 0b10001100;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘L’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10101100; // sending data
delay_ms(10);
PORTB= 0b10001100;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘O’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10101111; // sending data
delay_ms(10);
PORTB= 0b10001111;
delay_ms(10);
PORTB= 0b10100010; // sending data ‘SPACE’
delay_ms(10);
PORTB= 0b10000010;
delay_ms(10);
PORTB=0b10100000; // sending data
delay_ms(10);
PORTB=0b10000000;
delay_ms(10);
PORTB= 0b10100101; // sending data ‘W’
delay_ms(10);
PORTB= 0b10000101;
delay_ms(10);
PORTB= 0b10100111; // sending data
delay_ms(10);
PORTB= 0b10000111;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘O’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10101111; // sending data
delay_ms(10);
PORTB= 0b10001111;
delay_ms(10);
PORTB= 0b10100101; // sending data ‘R’
delay_ms(10);
PORTB= 0b10000101;
delay_ms(10);
PORTB= 0b10100010; // sending data
delay_ms(10);
PORTB= 0b10000010;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘L’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10101100; // sending data
delay_ms(10);
PORTB= 0b10001100;
delay_ms(10);
PORTB= 0b10100100; // sending data ‘D’
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);
PORTB= 0b10100100; // sending data
delay_ms(10);
PORTB= 0b10000100;
delay_ms(10);

return(0);
}

void io_init (void)
{
/*
PB 7: Data 7
PB 6: Data 6
PB 5: Data 5
PB 4: Data 4
PB 3: N/A
PB 2: Enable
PB 1: R/W
PB 0: Register Select
*/

DDRB =0b11101111;
}

void send_nibble(unsigned char __rs, unsigned char __data)
{
PORTB = (__rs<<4) | __data | 0b00100000; // Set RS & Data. Set EN=High
_delay_ms(10);
PORTB = (__rs<<4) | __data; // Set RS & Data. Set EN=Low
_delay_ms(10);
"

the error is

"> "make.exe" all

-------- begin --------
avr-gcc (WinAVR 20100110) 4.3.3
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


Compiling C: main.c
avr-gcc -c -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=8000000UL -Os -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wa,-adhlns=./main.lst -std=gnu99 -MMD -MP -MF .dep/main.o.d main.c -o main.o
main.c: In function 'main':
main.c:18: warning: implicit declaration of function 'delay_ms'
main.c: In function 'send_nibble':
main.c:140: error: expected declaration or statement at end of input
make.exe: *** [main.o] Error 1

> Process Exit Code: 2
> Time Taken: 00:01
"

Please help .....................

 

Good heavens! You have a ton of problems.

Why send out "HELLO WORLD" when you cannot even send "H".

Problem 1:
DDRB = 0b11111111;

Problem 2:
You need two routines, one to send a command, another to send data. Read the manual.

Problem 3:
You need to initialize the LCD. Read the manual.

Problem 4:
Learn to program in C.

 

I have to agree with the above. OP your code is an absolute mess, there are far easier ways to do this.

For one check your compiler libraries. Changes are one already exists to write to the LCD.

 

Inside int main (void) you comment out //io_init(); so one may ask how DO you init the I/O?

Looks like your send_nibble() routine is missing the last bracket } character to complete the function. Now since you did #include <util/delay.h> (where I would expect this function to live) and still got that error I would guess you have the name wrong. Check the documentation, or just scan delay.h to find what functions it does define.

Next, the warning "warning: implicit declaration of function 'delay_ms'" means the compiler has no idea what this function is.

I do expect you will have further errors once you fix those, but keep at it.