[SOLVED] some problem to my 16x2 LCD (second row always black)

[vinodstanur]

i bought a new 16X2 LCD (JHD 162A) .I connected it as follows.
VCC=5V
VSS=0V
VEE=0V
DATA NOT CONNECTED
RS NOT CONNECTED
R/W =0V
E NOT CONNECTED
LED CONNECTED


BUT, NOW WHEN I SWITCH ON THE 5V power supply, then the 2nd row displays all black!
and i then connected it to a pic16f877a with a "hello world" program...but still no change!!
what should i do now?

 

[prmurthy]

There is a possibility that the LCD is bad. You can try with disconnecting the RW and VEE pins.

Hope this helps you.

 

[mishra12]

if you just connect 1 ,3 to gnd and 2 to positive same result will come did you try
did you try in proteus same circuit
fake Chinese part is our headache

 

[lockman_akim]

actually..it not second row..it first row..i also have that black box..but when you program..it will work..

 

[vinodstanur]

thanks for the information...actually i thought it was the second row because there it written JHD 162A. At first i concluded my LCD was bad...now i will check my code ...

 

[lockman_akim]

yes..at the first time..i thought it second row too..

 

[ckshivaram]

its initialization of lcd problem... it will work .. try to debug the coe or execute a working program and test it...

 

[miskol]

try to program first. easier to just use a working example to check whether the LCD is broken or not. assuming u are going to ground the R/W, make sure the example program is also configured for that.

 

[vinodstanur]

MY PROGRAM: WORKING IN OSHONSOFT EMULATOR.

#include <htc.h>
#define _XTAL_FREQ 4e6 // 4MHz
__CONFIG(0x3F3A);
#define RS RD0
#define RW RD1
#define EN RD2

void display(unsigned char c)
{
RS=1;
PORTB=c;EN=1;EN=0;
__delay_us(200);
}

void init()
{
PORTB=0;PORTD=0;TRISD=0;TRISB=0;
command(0x30);
command(0x30);
command(0x30);
command(0x38 ); //8) is a smiley, so i had given a space here)//
command(0x08 ); //8) is a smiley, so i had given a space here)//
command(0x01);
command(0x06);
command(0x0C);

__delay_ms(20);
}



void command(int k)
{
RS=0;
PORTB=k;EN=1;EN=0;
__delay_ms(15);
}
void message(const char *s)
{
while(*s)
display(*s++);
}



void main()
{ __delay_ms(200);
init();

while(1)
{
message("hello world");
while(1){};
}

}

BUT STILL SAME PROBLEM!!

 

[chaudhryali55]

it is not a serious problem..i was having this but in my board there was a regulator that makes thoes boxes light and dark to show the display clearly.......if you can figure out the regulator then it will be great...and i hope so that it will work....

---------- Post added at 23:37 ---------- Previous post was at 23:33 ----------

MY PROGRAM: WORKING IN OSHONSOFT EMULATOR.

#include <htc.h>
#define _XTAL_FREQ 4e6 // 4MHz
__CONFIG(0x3F3A);
#define RS RD0
#define RW RD1
#define EN RD2

void display(unsigned char c)
{
RS=1;
PORTB=c;EN=1;EN=0;
__delay_us(200);
}

void init()
{
PORTB=0;PORTD=0;TRISD=0;TRISB=0;
command(0x30);
command(0x30);
command(0x30);
command(0x38 ); //8) is a smiley, so i had given a space here)//
command(0x08 ); //8) is a smiley, so i had given a space here)//
command(0x01);
command(0x06);
command(0x0C);

__delay_ms(20);
}



void command(int k)
{
RS=0;
PORTB=k;EN=1;EN=0;
__delay_ms(15);
}
void message(const char *s)
{
while(*s)
display(*s++);
}



void main()
{ __delay_ms(200);
init();

while(1)
{
message("hello world");
while(1){};
}

}

BUT STILL SAME PROBLEM!!

try to use this code it is built in code in mikro c compiler and this ode will run in 4 bit mode..i was having the same problem but it figured out...

sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;

sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections

char txt1[] = "mikroElektronika";    
char txt2[] = "EasyPIC5";
char txt3[] = "Lcd4bit";
char txt4[] = "example";

char i;                              // Loop variable

void Move_Delay() {                  // Function used for text moving
  Delay_ms(500);                     // You can change the moving speed here
}

void main(){
  TRISB = 0;
  PORTB = 0xFF;
  TRISB = 0xff;
  ANSEL  = 0;                        // Configure AN pins as digital I/O
  ANSELH = 0;
  Lcd_Init();                        // Initialize LCD

  Lcd_Cmd(_LCD_CLEAR);                // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF);           // Cursor off
  Lcd_Out(1,6,txt3);                 // Write text in first row

  Lcd_Out(2,6,txt4);                 // Write text in second row
  Delay_ms(2000);
  Lcd_Cmd(_LCD_CLEAR);                // Clear display

  Lcd_Out(1,1,txt1);                 // Write text in first row
  Lcd_Out(2,5,txt2);                 // Write text in second row

  Delay_ms(2000);

  // Moving text
  for(i=0; i<4; i++) {               // Move text to the right 4 times
    Lcd_Cmd(_LCD_SHIFT_RIGHT);
    Move_Delay();
  }

  while(1) {                         // Endless loop
    for(i=0; i<8; i++) {             // Move text to the left 7 times
      Lcd_Cmd(_LCD_SHIFT_LEFT);
      Move_Delay();
    }

    for(i=0; i<8; i++) {             // Move text to the right 7 times
      Lcd_Cmd(_LCD_SHIFT_RIGHT);
      Move_Delay();
    }
  }
}

 

[vinodstanur]

SUCCESS!!!!! I used my micro C sample program...its working ! So what may be the problem in my program?

 

[lockman_akim]

i think u should change the configuration..
try use the configuration from sample and just edit certain part..

 

[chaudhryali55]

SUCCESS!!!!! I used my micro C sample program...its working ! So what may be the problem in my program?

the problem is you were using the delay_ms(200) which means delay 200 milli seconds...which a normal eye can not even see it when you use it on the hardware...and the delay_ms(15) also...ans as lockman said there is problem in confguring the bits of the lcd u didnt defined the data ports of the lcd...how can the display should be shown......