Hi Peeps,

I'm using the below example code to get the GLCD up and running and find my way around it.
However I don't get any output on the screen. Contrast is fine and the built in GLCD contrast control takes it from a blue screen to off white square pixels showing a clear border where the printable area is.

Just wondering if you guys can see anything obvious?

H/W: EasyPIC V7 Dev Board, ICD3, WDG0151-TMI GLCD, PIC16F877, Salea 16.
S/W: MPLABX v5.4, XC8 v2.31.

/*
 * File:   main.c
 * Author: Example Code from exploreembedded.com
 * Created on 09 January 2021, 23:37
 * Project name: Testing GLCD with PIC16F887
*/

// CONFIG
#pragma config FOSC = XT        // Oscillator Selection bits (XT oscillator)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config CP = OFF         // FLASH Program Memory Code Protection bits (Code protection off)
#pragma config BOREN = ON       // Brown-out Reset Enable bit (BOR enabled)
#pragma config LVP = OFF        // Low Voltage In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)
#pragma config CPD = OFF        // Data EE Memory Code Protection (Code Protection off)
#pragma config WRT = ON         // FLASH Program Memory Write Enable (Unprotected program memory may be written to by EECON control)

#include <xc.h>

#define  _XTAL_FREQ 4000000L   

/**
 *  Control bus PB0:PB4
 *  Data bus PD0:PD7
 */

#define GlcdDataBus      PORTD
#define GlcdControlBus   PORTB

#define GlcdDataBusDirnReg   TRISD
#define GlcdCtrlBusDirnReg   TRISB

#define CS1     0x00       // Select segments 1-64
#define CS2     0x01       // Select segments 65-128
#define RS      0x02       // H: Data - L: Instruction
#define RW      0x03       // H: Read Data - L: Write Data
#define EN      0x04       // Enable

/* 5x7 Font including 1 space to display HELLO WORLD */
char H[]={0x7F, 0x08, 0x08, 0x08, 0x7F, 0x00};
char E[]={0x7F, 0x49, 0x49, 0x49, 0x41, 0x00};
char L[]={0x7F, 0x40, 0x40, 0x40, 0x40, 0x00};
char O[]={0x3E, 0x41, 0x41, 0x41, 0x3E, 0x00};

char W[]={0x3F, 0x40, 0x38, 0x40, 0x3F, 0x00};
char R[]={0x7F, 0x09, 0x19, 0x29, 0x46, 0x00};
char D[]={0x7F, 0x41, 0x41, 0x22, 0x1C, 0x00};


void Glcd_SelectPage0() // CS1=1, CS2=0
{
    GlcdControlBus |= (1<<CS1);
    GlcdControlBus &= ~(1<<CS2);
}

void Glcd_SelectPage1() // CS1=0, CS1=1
{
    GlcdControlBus &= ~(1<<CS1);
    GlcdControlBus |= (1<<CS2);
}

/* Function to send the command to LCD */
void Glcd_CmdWrite(char cmd)
{
    
    GlcdControlBus |= (1<<EN);   // Generate a High-to-low pulse on EN pin
    __delay_us(500);
    GlcdDataBus = cmd;           //Send the Command byte
    GlcdControlBus &= ~(1<<EN);  // Bring the EN pin low again
    
    GlcdControlBus &= ~(1<<RS);  // Send LOW pulse on RS pin for selecting Command register
    GlcdControlBus &= ~(1<<RW);  // Send LOW pulse on RW pin for Write operation
    

    __delay_us(1000);
}

/* Function to send the Data to LCD */
void Glcd_DataWrite(char dat)
{
    

    GlcdControlBus |= (1<<EN);   // Generate a High-to-low pulse on EN pin
    __delay_us(500);
    GlcdDataBus = dat;           //Send the data on DataBus byte
    GlcdControlBus &= ~(1<<EN);  // Bring the EN pin low again
    GlcdControlBus |= (1<<RS);   // Send HIGH pulse on RS pin for selecting data register
    GlcdControlBus &= ~(1<<RW);  // Send LOW pulse on RW pin for Write operation
    

    __delay_us(1000);
}

void Glcd_DisplayChar(char *ptr_array)
{
    int i;
    for(i=0;i<6;i++) // 5x7 font, 5 chars + 1 blank space
        Glcd_DataWrite(ptr_array[i]);
}
                                                                  

int main()
{
    GlcdDataBusDirnReg = 0x00;  // Configure all the Data (PORTD) pins as output
    GlcdCtrlBusDirnReg = 0x00;  // Configure the Ctrl (PORTB) pins as output

    /* Select the Page0/Page1 and Turn on the GLCD */
    Glcd_SelectPage0();     // CS1=1, CS2=0
    Glcd_CmdWrite(0x3F);    //
    Glcd_SelectPage1();     // CS1=0, CS1=1
    Glcd_CmdWrite(0x3F);    //
    __delay_us(500);
    
    /* Select the Page0/Page1 and Enable the GLCD */
    Glcd_SelectPage0();     // CS1=1, CS2=0
    Glcd_CmdWrite(0xC0);    //
    Glcd_SelectPage1();     // CS1=0, CS1=1
    Glcd_CmdWrite(0xC0);    //
    __delay_us(500);

    Glcd_SelectPage0();     // Display HELLO on Page0, Line1
    Glcd_CmdWrite(0xB8);    // 0xB8 = line 0 (the top line)
    Glcd_DisplayChar(H);
    Glcd_DisplayChar(E);
    Glcd_DisplayChar(L);
    Glcd_DisplayChar(L);
    Glcd_DisplayChar(O);

    Glcd_SelectPage1();     // Display WORLD on Page1, Last line
    Glcd_CmdWrite(0xBF);    // 0xB8 = line 7 (the bottom line)
    Glcd_DisplayChar(W);
    Glcd_DisplayChar(O);
    Glcd_DisplayChar(R);
    Glcd_DisplayChar(L);
    Glcd_DisplayChar(D);

    while(1);
}

Any suggestions would be appreciated.

Regards
GB

 

As you know, that display has two controllers (CS1 and CS2). Each controls 1/2.

Are you setting the column (e.g., 0...63) where you want to start printing? Column increments automatically. I didn't see that Command.



Sorry if that is obvious. I don't do C