Newhaven Display Forum

Newhaven Products => Character LCDs => Topic started by: YSUN on November 21, 2014, 02:24:38 PM

Title: Nothing Display on my NHD-0108CZ-FSW-GBW-33V3
Post by: YSUN on November 21, 2014, 02:24:38 PM

Hi, All

I have been working on this LCD several days, but get no display on the screen. Firstly, I am pretty sure that all the connections are correct. Here I writing for asking help about the code .

I use the Atmel studio 6.2 , the board is atmega328p mini . PortB0 --PortB7 are for the bus line (8-bit ), PortD pin 0 , 1 , 2 are the control pins.

My code is written  based on the example program code given on Newhaven website (   you can find the demo code here : http://www.newhavendisplay.com/app_notes/8_bit_character_C.txt )

And here below is my code :

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

#define E PORTB0 // en
#define Rw PORTB1 // R/W
#define Rs PORTB2 // RS

volatile xdata_at_0xB0_char_E;
volatile xdata_at_0xB1_char_Rw;
volatile xdata_at_oxB2_char_Rs;

char const text[] = {"eniware-"};

//void commamd ( char i );
//void write ( char i );
//void init();
//void disp_pic();
//void main(void);

void command (char i)
{
   PORTD = i;
   PORTB &= ~ (1<<Rs);// rs = 0
   PORTB &= ~(1<<Rw);// rw =0
   PORTB |= 1<<E;// en = 1
   _delay_ms(10);
   PORTB &= ~(1<<E); // en = 0
}

void write (char i)
{
   PORTD = i;
   PORTB |= (1<<Rs); // rs 1
   PORTB &= ~ (1<<Rw); // rw 0
   PORTB |= 1<<E; // en 1
   _delay_ms(10);
   PORTB &= ~ (1<<E); // en 0
}

void init()
{
   PORTB &= ~ (1<<E); // en 0
   _delay_ms(10);
   
   command(0x30); //#1
   _delay_ms(100);
   command(0x30); //#2
   _delay_ms(10);
   command(0x30); //#3
   _delay_ms(10);
   
   command(0x38);
   command(0x10);
   command(0x0c);
   command(0x06);

}

void disp_pic()
{
   int i;
   command(0x01);
   _delay_ms(10);
   
   for (i=0;i<8;i++)
   {
      write(text);
   }
   
}

void main (void)
{
   PORTD = 0;
   PORTB = 0;
   while(1)
   {
      init();
      disp_pic();
      _delay_ms(1000);
   }
}

Is there anyone can tell me what is wrong with my code ?  Many thanks in advance.

Title: Re: Nothing Display on my NHD-0108CZ-FSW-GBW-33V3
Post by: Michael_L on November 24, 2014, 08:52:12 AM

Our example code is verified to work correctly.  Have you verified your signals are working/toggling correctly with a scope?
Also, typically you need to set up the ports as outputs in your code.
For example :
DDRB = 0xFF;
DDRD = 0xFF;