Digole Digital Solution's Forum

Pen

Total Posts:: 3
Since:: 2017-Mar-09
From:: Luxembourg

PIC16f877A

Posted at:2017-03-09 11:01:47

Please can anyone help me get started with displaying anything on the digole 12864ZW.

I have been trying for months now to get the display to show anything from the CGRAM or GDRAM to no avail.
I'm using MPLABX XC8 compiler and the Hobby components PIC16f877A development board

I'm using 8bit parallel mode (basic instr set for CGRAM characters) (extended instr set for GDRAM)
the Data port is portD and RS, RW, EN use portE RE0, RE1 and RE2 respectively.

Up to now all I have been able to display is the odd fleeting ASCII character and more often just a random set of flashing blocks on the screen.

I have tried all kinds of delays and timings. Also I don't seem to be able to read the busy flag, I always find it in the not busy state '0'

Service

Total Posts:: 411
Since:: 2013-Dec-22
From:: Canada

RE:PIC16f877A

Posted at:2017-07-08 19:07:07 Edited at:2017-07-08 19:14:43

char DATA_TAB[1024]; //screen buffer

void InitLCD_ST7920(void) {

unsigned char x, y;

Delay_us(20);

Ssd_Command(0x30); //basic mode, 8bit interface

Ssd_Command(0x0C); //LCD on

Ssd_Command(0x01); //Display clear TEXT

Ssd_Command(0x02); //Return to home

Ssd_Command(0x36); //Graph Mode 8bit interface, graph on

for (y = 0; y < 32; y++) //clear graphic RAM

{

Ssd_Command(0x80 | y); //y

Ssd_Command(0x80); //x

for (x = 0; x < 32; x++) {

Ssd_Data(0);

}

void freshscreen_ST7920(void) {

volatile unsigned int ptr;

ptr = 0;

Ssd_Command(0x36); //Graph Mode 8bit interface, graph on

for (unsigned char i = 0; i < 32; i++) {

Ssd_Command(0x80 + i); //set low column address

Ssd_Command(0x80); //set high column address 10

for (char j = 0; j < 16; j++) {

Ssd_Data(DATA_TAB[ptr++]);

}

for (char i = 0; i < 32; i++) {

Ssd_Command(0x80 + i); //set low column address

Ssd_Command(0x88); //set high column address 10

for (char j = 0; j <16; j++) {

Ssd_Data(DATA_TAB[ptr++]);

}

Service Total Posts: 411 Since: 2013-Dec-22 From: Canada	RE:PIC16f877A Posted at:2017-07-08 19:16:05
	Or you can use our Universal adapter to drive the display: http://www.digole.com/index.php?productID=1269