S/W: MPLABX, XC8
4MHz Xtal
Untill my newer PIC16F18877's turn up, I'm using this chip. But with the help of some tweaked example code I'm trying to find my way around a GLCD.
Example code from https://www.exploreembedded.com/wiki/Interfacing_GLCD(128x64)_with_PIC16F877A
Here's the code I'm using..
- Code: Select all
/*
* File: main.c
* Author: Example Code from exploreembedded.com
* Created on 09 January 2021, 23:37
*/
// 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>
#include <pic.h>
#include <pic16f877.h>
#include <htc.h>
#include <stdio.h>
/*
* Project name: Testing GLCD with PIC16F887
*/
#define FOSC = 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};
/* local function to generate delay */
void delay(int cnt)
{
int i;
for(i=0;i<cnt;i++);
}
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)
{
GlcdDataBus = cmd; //Send the Command nibble
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
GlcdControlBus |= (1<<EN); // Generate a High-to-low pulse on EN pin
delay(100);
GlcdControlBus &= ~(1<<EN);
delay(1000);
}
/* Function to send the Data to LCD */
void Glcd_DataWrite(char dat)
{
GlcdDataBus = dat; //Send the data on DataBus nibble
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
GlcdControlBus |= (1<<EN); // Generate a High-to-low pulse on EN pin
delay(100);
GlcdControlBus &= ~(1<<EN);
delay(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 LCD pins as output
GlcdCtrlBusDirnReg = 0x00; // Configure the Ctrl pins as output
/* Select the Page0/Page1 and Turn on the GLCD */
Glcd_SelectPage0(); //
Glcd_CmdWrite(0x3F); //
Glcd_SelectPage1(); //
Glcd_CmdWrite(0x3F); //
delay(100);
/* Select the Page0/Page1 and Enable the GLCD */
Glcd_SelectPage0(); //
Glcd_CmdWrite(0xC0); //
Glcd_SelectPage1(); //
Glcd_CmdWrite(0xC0); //
delay(100);
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);
}
... and here's the output on the analyser.
- GLCD analyser output
- GLCD_nalyser-01.png (112.07 KiB) Viewed 4623 times
Problem is that there is no output on the screen, pixels are illuminated and contrast is adjustable.
Any suggestions would be appreciated
Regards
GB
