The 128 x 64 graphics displays (GLCDs) like JHD12864 and other use KS0108 as the display controller. In this tutorial we will look at interfacing such a display with Explore M3. We will be using a graphics library written by Michael Margolis.

Hookup

The pinout may differ according to the make of the LCD. For this sketch to work ensure that the pins are connected in the following manner. If you wish to change the pin configuration, it can be done in KS0108_pins.h file.

Display	Explore M3	Description
D_I	2	Data direction or Register Select
R_W	3	Read/Write
EN	4	Enable
D0	5	8 bit Data Bus
D1	6
D2	7
D3	8
D4	9
D5	10
D6	11
D7	12
CSEL1	13	Chip select 1
CSEL2	14	Chip Select 2

Since there are numerous connections and few passive parts to set the contrast and negative voltage etc. I will be using the LCD breakout board and the JHD12864 display that we see at our EE Store.

Code

I will be using the demo code in the library which shows various shapes fonts and objects. This comes with the library itself.

	/*
	* GLCDexample
	*
	* Basic test code for the Arduino KS0108 GLCD library.
	* This code exercises a range of graphic functions supported
	* by the library and is an example of its use.
	* It also gives an indication of performance, showing the
	* number of frames drawn per second.
	*/

	#include <ks0108.h>
	#include "Arial14.h" // proportional font
	#include "SystemFont5x7.h" // system font
	#include "ArduinoIcon.h" // bitmap

	unsigned long startMillis;
	unsigned int loops = 0;
	unsigned int iter = 0;

	void setup(){
	delay(500); // allow time for LCD to reset
	GLCD.Init(NON_INVERTED); // initialise the library, non inverted writes pixels onto a clear screen
	GLCD.ClearScreen();
	GLCD.DrawBitmap(ArduinoIcon, 32,0, BLACK); //draw the bitmap at the given x,y position
	GLCD.SelectFont(System5x7); // switch to fixed width system font
	countdown(5);
	GLCD.ClearScreen();
	introScreen(); // show some intro stuff
	GLCD.ClearScreen();
	}

	void introScreen(){
	GLCD.SelectFont(Arial_14); // you can also make your own fonts, see playground for details
	GLCD.GotoXY(20, 2);
	GLCD.Puts("GLCD version ");
	GLCD.PrintNumber(GLCD_VERSION);
	GLCD.DrawRoundRect(16,0,99,18, 5, BLACK); // rounded rectangle around text area
	GLCD.SelectFont(System5x7); // switch to fixed width system font
	showCharacters();
	countdown(5);
	}

	void showCharacters(){
	byte line = 3; // start on the fourth line
	for(byte c = 32; c <=127; c++){
	if( (c-32) % 20 == 0)
	GLCD.CursorTo(1,line++); // CursorTo is used for fixed width system font
	GLCD.PutChar(c);
	}
	}

	void drawSpinner(byte pos, byte x, byte y) {
	// this draws an object that appears to spin
	switch(pos % 8) {
	case 0 : GLCD.DrawLine( x, y-8, x, y+8, BLACK); break;
	case 1 : GLCD.DrawLine( x+3, y-7, x-3, y+7, BLACK); break;
	case 2 : GLCD.DrawLine( x+6, y-6, x-6, y+6, BLACK); break;
	case 3 : GLCD.DrawLine( x+7, y-3, x-7, y+3, BLACK); break;
	case 4 : GLCD.DrawLine( x+8, y, x-8, y, BLACK); break;
	case 5 : GLCD.DrawLine( x+7, y+3, x-7, y-3, BLACK); break;
	case 6 : GLCD.DrawLine( x+6, y+6, x-6, y-6, BLACK); break;
	case 7 : GLCD.DrawLine( x+3, y+7, x-3, y-7, BLACK); break;
	}
	}

	void countdown(int count){
	while(count--){ // do countdown
	GLCD.CursorTo(0,1); // first column, second row (offset is from 0)
	GLCD.PutChar(count + '0');
	delay(1000);
	}
	}

	void loop(){ // run over and over again
	iter = 0;
	startMillis = millis();
	while( millis() - startMillis < 1000){ // loop for one second
	GLCD.DrawRect(0, 0, 64, 61, BLACK); // rectangle in left side of screen
	GLCD.DrawRoundRect(68, 0, 58, 61, 5, BLACK); // rounded rectangle around text area
	for(int i=0; i < 62; i += 4)
	GLCD.DrawLine(1,1,63,i, BLACK); // draw lines from upper left down right side of rectangle
	GLCD.DrawCircle(32,31,30,BLACK); // draw circle centered in the left side of screen
	GLCD.FillRect(92,40,16,16, WHITE); // clear previous spinner position
	drawSpinner(loops++,100,48); // draw new spinner position
	//GLCD.FillRect(24,txtLINE3,14,14, WHITE); // clear text area that will be drawn below
	GLCD.CursorTo(5,5); // locate curser for printing text
	GLCD.PrintNumber(++iter); // print current iteration at the current cursor position
	}
	// display number of iterations in one second
	GLCD.ClearScreen(); // clear the screen
	GLCD.CursorTo(14,2); // positon cursor
	GLCD.Puts("FPS= "); // print a text string
	GLCD.PrintNumber(iter); // print a number
	}