Please help with school project of PIC16f864 + 2x16 LCD

[tonyela]

View attachment 67045Hello all,
I try to have the message display on the 2x16 lcd, but show nothing. In proteus it does show perfectly what I want it to show, but when I implemented with the real chip, it does not show anything. I did play with the contract... but it only show blank square dot.
Thank you for your help.

here is the code and schematic:
// LCD module connections
sbit LCD_RS at RC5_bit;
sbit LCD_EN at RC4_bit;
sbit LCD_D4 at RC0_bit;
sbit LCD_D5 at RC1_bit;
sbit LCD_D6 at RC2_bit;
sbit LCD_D7 at RC3_bit;

sbit LCD_RS_Direction at TRISC5_bit;
sbit LCD_EN_Direction at TRISC4_bit;
sbit LCD_D4_Direction at TRISC0_bit;
sbit LCD_D5_Direction at TRISC1_bit;
sbit LCD_D6_Direction at TRISC2_bit;
sbit LCD_D7_Direction at TRISC3_bit;
// End LCD module connections



void main()
{



TRISA = 0xFF; // PORTA is input except RA4
ANSEL = 0x03; // Configure AN0, AN1, pin as analog
// (Without this also could cause controller received data whlst busy msg)
PORTC = 0; // Set all pins on PORTC to low
TRISC = 0; // All of PORTC are outputs
lcd_cmd(0x20); // 4-bit mode - 2 line - 5x7 font.
delay_ms(1000);
lcd_init();
delay_ms(1000);
//lcd_cmd(0x28); // 4-bit mode - 2 line - 5x7 font.


LCD_cmd(_LCD_TURN_ON);
delay_ms(100);
LCD_cmd(_LCD_CLEAR); // Clear LCD
delay_ms(100);
LCD_cmd(_LCD_CURSOR_OFF);
delay_ms(100);


do
{

Lcd_Out(1,1,"Welcome to LCD");
lcd_out(2,1,"and PIC16f684");
delay_ms(1000);
} while(1);
}

 

[Ian Rogers]

You have a command BEFORE your Lcd_init()... The Lcd_cmd().. shouldn't be there.... Someone with mikroC experience will show you how soon.

 

[tonyela]

Hello Ian, Thank you for your respond, I remove the lcd_cmd line and it still not work. I also connect the led from RA5 to gnd... I can see it blinking... but nothing show on the screen... just the square box on the line 1.

 

[aljamri]

One more thing to check, In hardware, the LCD Pot is 100Ω?, the recommended is 5000Ω.

 

[aljamri]

TRISA = 0xFF; // PORTA is input except RA4

this command will set all PORTA pins as input, since 0xFF in hex = 1111 1111 in Bin.

I suggest you try simple example given in MikroC help to initialize your LCD and then try your code, change the pins according to your setup:

char *text = "mikroElektronika";

void main() {
  TRISB = 0;                // PORTB is output
  Lcd_Init(&PORTB);         // Initialize LCD connected to PORTB
  Lcd_Cmd(Lcd_CLEAR);       // Clear display
  Lcd_Cmd(Lcd_CURSOR_OFF);  // Turn cursor off
  Lcd_Out(1, 1, text);      // Print text to LCD, 2nd row, 1st column
}//~!

 

[Ian Rogers]

Also you need to include the command "CMCON0 = 0x7" as the comparators are on PORTC

 

[tonyela]

Hey! what do you know... the command CMCON0 = 0x7 did fixed my problem. Although it also dumping some garbage on the LCD. but it is a good sign.. Thank you very very much guys, both of you were very helpful. you guys are great. Thank you again.

 

[WTP Pepper]

Long time since I have played with PICs, but shouldn't PORTC have some form of I/O register to tell the CPU which way you want control e.g. a DDR data direction register.
On most processors, PORTC=0 is meaningless as most come out of reset set as inputs.

 

[Ian Rogers]

WTP!! It's

TRISC = 0; // All of PORTC are outputs

In the program

 

[WTP Pepper]

WTP!! It's

In the program

No probs. Like I say, it's been a few years. Thanks for the info.

 

[Ian Rogers]

WTP!! It's

In the program

Sorry ..... That sounded rude.... I really didn't mean to be..

 

[WTP Pepper]

Sorry ..... That sounded rude.... I really didn't mean to be..

No offence taken.

I personally avoid this kind of syntax as to me (in my case about 3 years) or to a reviewer can become meaniless despite being valid syntax.

On an 8051 core...
REFSL=1; is valid but what does it mean? You have to trawl the header files or data sheet to find where REFSL is referenced by a Special Function Register.

I would prefer using the exact SFR followed by a brief explaining comment
REF0CN |=0x08; // use VDD as a reference voltage.

I am not particularly interested in what the bit name is, just where to find it and if in the register there are any corresponding bits affected.

Which I suppose unlike many you did.

 

[Mr RB]

I agree WTPpepper. MikroC (that the OP is using) has a nice feature of allowing base2 constants, so
TRISC = 0;

can be displayed better as
TRISC = 0b00000000;

which allows good commenting like;
TRISC = 0b10000011; // RC7 is USART RX, RC2-6 are LEDs, RC0,1 buttons