Can't initialize Qapass 1602A LCD with PIC18F4620 - pic

Question

I can't initialize a QAPASS 1602A LCD with a PIC18F4620, I always get square blocks on both lines. In the beginning, I thought the LCD was broken so I got a new one but the outcome is the same. I use a logifind PIC 40 Mini development board connected to PC through a PICkit3, everything else is working fine on every port but not the LCD.
Thanks a lot for your help.
//main.c
#include "newxc8_header.h"
#include <xc.h>
#include "lcd_16x2.h"
void main(void) {
ADCON1=0x0F; //configuring all analog ports to digital
TRISB=0x00; //Set RBs as output
TRISD=0x00; //Set RDs as output
TRISE=0x00; //Set REs as output
LCD_Init(); //Initialize 16x2 LCD
LCD_String("Hello");
while(1);
}
//lcd_16x2.c
#include "lcd_16x2.h"
void LCD_Init(void)
{
__delay_ms(1000);
EN = 0;
RS = 0;
ldata = 0x00;
LCD_Command(0x38); // Initialization of 16X2 LCD: 8-bit, 2 Lines, 5x7 Dots
LCD_Command(0x0C); // Display ON Cursor OFF
LCD_Command(0x01); //clear LCD
LCD_Command(0x02); //cursor beginning first line
}
void LCD_Command(unsigned char cmd)
{
ldata = cmd; /* Send data to PORT as a command for LCD */
RS = 0; /* Command Register is selected */
EN = 1; /* High-to-Low pulse on Enable pin to latch data */
__delay_ms(5);
EN = 0;
__delay_ms(3);
}
void LCD_Char(unsigned char data)
{
ldata = data; /* Send data to LCD */
RS = 1; // Data Register is selected */
EN = 1; // High-to-Low pulse on Enable pin to latch data */
__delay_ms(5);
EN = 0;
__delay_ms(3);
}
void LCD_String(const char *msg)
{
while(*msg != 0)
{
LCD_Char(*msg);
msg++;
}
}
//lcd_16x2.h
#ifndef LCD_16X2_H
#define LCD_16X2_H
#ifdef __cplusplus
extern "C" {
#endif
#include <xc.h>
#define _XTAL_FREQ 16000000 //16 MHz (4 MHz x 4 PLL)
#define ldata LATB /*PORTB(RB0-RB7) is used for transmitting data to LCD*/
#define RS LATEbits.LATE0 /*RE0 pin is used for Register Select*/
#define EN LATEbits.LATE1 /*RE1 pin is used for Enable*/
void LCD_Init(void);
void LCD_Command(unsigned char );
void LCD_Char(unsigned char x);
void LCD_String(const char *);
void LCD_Clear();
#ifdef __cplusplus
}
#endif
#endif /* NEWFILE_H */

Answer 1

Your question does not contain enough details for a definitive answer.
The best guess is that you have a wiring error between your LogiFind PIC-40-MINI board:
and your QAPASS 1602A LCD module:
A photograph of how they are connected would be helpful.
If you are convinced the wiring is correct then a problem may be in the LCD_Init() function, see HD44780 data sheet page 45 for a flowchart about initializing the module in 8-bit parallel mode or in the code you have not posted.
Added on January 19, 2020:
I assembled a PIC18F4620 and LCD module as you described.
Found that your code as posted does not show the configuration words you are using.
When using the internal oscillator at the default frequency (1MHz) your code runs but it's 16 times slower than expected.
After adjusting some settings this is the final version of code:
//main.c
// PIC18F4620 Configuration Bit Settings
// 'C' source line config statements
// CONFIG1H
#pragma config OSC = INTIO67 // Oscillator Selection bits (Internal oscillator block, port function on RA6 and RA7)
#pragma config FCMEN = OFF // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)
#pragma config IESO = OFF // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)
// CONFIG2L
#pragma config PWRT = OFF // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = OFF // Brown-out Reset Enable bits (Brown-out Reset disabled in hardware and software)
#pragma config BORV = 3 // Brown Out Reset Voltage bits (Minimum setting)
// CONFIG2H
#pragma config WDT = OFF // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit))
#pragma config WDTPS = 32768 // Watchdog Timer Postscale Select bits (1:32768)
// CONFIG3H
#pragma config CCP2MX = PORTC // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1)
#pragma config PBADEN = OFF // PORTB A/D Enable bit (PORTB<4:0> pins are configured as digital I/O on Reset)
#pragma config LPT1OSC = OFF // Low-Power Timer1 Oscillator Enable bit (Timer1 configured for higher power operation)
#pragma config MCLRE = ON // MCLR Pin Enable bit (MCLR pin enabled; RE3 input pin disabled)
// CONFIG4L
#pragma config STVREN = ON // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset)
#pragma config LVP = OFF // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled)
#pragma config XINST = OFF // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))
// CONFIG5L
#pragma config CP0 = OFF // Code Protection bit (Block 0 (000800-003FFFh) not code-protected)
#pragma config CP1 = OFF // Code Protection bit (Block 1 (004000-007FFFh) not code-protected)
#pragma config CP2 = OFF // Code Protection bit (Block 2 (008000-00BFFFh) not code-protected)
#pragma config CP3 = OFF // Code Protection bit (Block 3 (00C000-00FFFFh) not code-protected)
// CONFIG5H
#pragma config CPB = OFF // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected)
#pragma config CPD = OFF // Data EEPROM Code Protection bit (Data EEPROM not code-protected)
// CONFIG6L
#pragma config WRT0 = OFF // Write Protection bit (Block 0 (000800-003FFFh) not write-protected)
#pragma config WRT1 = OFF // Write Protection bit (Block 1 (004000-007FFFh) not write-protected)
#pragma config WRT2 = OFF // Write Protection bit (Block 2 (008000-00BFFFh) not write-protected)
#pragma config WRT3 = OFF // Write Protection bit (Block 3 (00C000-00FFFFh) not write-protected)
// CONFIG6H
#pragma config WRTC = OFF // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected)
#pragma config WRTB = OFF // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)
#pragma config WRTD = OFF // Data EEPROM Write Protection bit (Data EEPROM not write-protected)
// CONFIG7L
#pragma config EBTR0 = OFF // Table Read Protection bit (Block 0 (000800-003FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR1 = OFF // Table Read Protection bit (Block 1 (004000-007FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR2 = OFF // Table Read Protection bit (Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks)
#pragma config EBTR3 = OFF // Table Read Protection bit (Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks)
// CONFIG7H
#pragma config EBTRB = OFF // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)
#include <xc.h>
#include "lcd_16x2.h"
void main(void) {
OSCCON = 0b01100000; // sets clock = 4MHz
OSCTUNE = 0b01000000; // turn on 4xPLL
ADCON1=0x0F; //configuring all analog ports to digital
TRISB=0x00; //Set RBs as output
TRISD=0x00; //Set RDs as output
TRISE=0x00; //Set REs as output
LCD_Init(); //Initialize 16x2 LCD
LCD_Command(0x80);
LCD_String("Hello");
LCD_Command(0xC0);
LCD_String(__TIME__ " v1 ");
while(1);
}
//lcd_16x2.c
#include <xc.h>
#include "lcd_16x2.h"
void LCD_Init(void)
{
__delay_ms(1000);
EN = 0;
RS = 0;
LCD_Command(0x38); // Initialization of 16X2 LCD: 8-bit, 2 Lines, 5x7 Dots
LCD_Command(0x0C); // Display ON Cursor OFF
LCD_Command(0x01); //clear LCD
LCD_Command(0x02); //cursor beginning first line
}
void LCD_Command(unsigned char cmd)
{
ldata = cmd; /* Send data to PORT as a command for LCD */
RS = 0; /* Command Register is selected */
EN = 1; /* High-to-Low pulse on Enable pin to latch data */
__delay_us(1);
EN = 0;
__delay_ms(4);
}
void LCD_Char(unsigned char data)
{
ldata = data; /* Send data to LCD */
RS = 1; // Data Register is selected */
EN = 1; // High-to-Low pulse on Enable pin to latch data */
__delay_us(1);
EN = 0;
__delay_us(50);
}
void LCD_String(const char *msg)
{
while(*msg != 0)
{
LCD_Char(*msg);
msg++;
}
}
//lcd_16x2.h
#ifndef LCD_16X2_H
#define LCD_16X2_H
#ifdef __cplusplus
extern "C" {
#endif
#include <xc.h>
#define _XTAL_FREQ 16000000 //16 MHz (4 MHz x 4 PLL)
#define ldata LATB /*PORTB(RB0-RB7) is used for transmitting data to LCD*/
#define RS LATEbits.LATE0 /*RE0 pin is used for Register Select*/
#define EN LATEbits.LATE1 /*RE1 pin is used for Enable*/
void LCD_Init(void);
void LCD_Command(unsigned char );
void LCD_Char(unsigned char x);
void LCD_String(const char *);
void LCD_Clear();
#ifdef __cplusplus
}
#endif
#endif /* NEWFILE_H */