Objective

If you have done with simple 16x2 LCD and still want to do more with display, its time to have fun with Graphics LCD.

We all really enjoy animations kind of things and this is the stuff what we can do with GLCD.

GLCD is very similar to simple 16x2 LCD with additional features. To explore these features and functionality you would like to see our tutorial Graphics LCD Basics : KS0108 based JHD12864E

Schematic

Port Connection

This section shows how to configure the GPIO for interfacing the GLCD.
The below configuration is as per the above schematic. You can connect the GLCD to any of the PORT pins available on your boards and update this section accordingly

	/* Configure the data bus and Control bus as per the hardware connection */
	#define GlcdDataBusPort LPC_GPIO1->FIOPIN
	#define GlcdControlBusPort LPC_GPIO2->FIOPIN

	#define GlcdDataBusDirnReg LPC_GPIO1->FIODIR
	#define GlcdCtrlBusDirnReg LPC_GPIO2->FIODIR


	#define GLCD_D0 20
	#define GLCD_D1 21
	#define GLCD_D2 22
	#define GLCD_D3 23
	#define GLCD_D4 24
	#define GLCD_D5 25
	#define GLCD_D6 26
	#define GLCD_D7 27

	#define GLCD_RS 0
	#define GLCD_RW 1
	#define GLCD_EN 2
	#define GLCD_CS1 3
	#define GLCD_CS2 4

view raw lpc1768_glcd_portConctn.c hosted with ❤ by GitHub

GLCD Operation

In this section we are going to see how to send the data/cmd to the GLCD along with the timing diagrams. First lets see the timing diagram for sending the data and the command signals(RS,RW,EN), accordingly we write the algorithm and finally the code.

Timing Diagram

The below image shows the timing diagram for sending the data to the GLCD.
As shown in the timing diagram the data is written after sending the RS and RW signals. It is still ok to send the data before these signals.
The only important thing is the data should be available on the databus before generating the High-to-Low pulse on EN pin.

Steps for Sending Command:

step1: Send the I/P command to GLCD.
step2: Select the Control Register by making RS low.
step3: Select Write operation making RW low.
step4: Send a High-to-Low pulse on Enable PIN with some delay_us.

	/* Function to send the command to LCD */
	void Glcd_CmdWrite(char cmd)
	{
	sendByte(cmd); //Send the command
	GlcdControlBusPort &= ~(1<<GLCD_RS); // Send LOW pulse on RS pin for selecting Command register
	GlcdControlBusPort &= ~(1<<GLCD_RW); // Send LOW pulse on RW pin for Write operation
	GlcdControlBusPort \|= (1<<GLCD_EN); // Generate a High-to-low pulse on EN pin
	delay(1000);
	GlcdControlBusPort &= ~(1<<GLCD_EN);

	delay(10000);
	}

view raw glcd_cmdWrite.c hosted with ❤ by GitHub

Steps for Sending Data:

step1: Send the character to GLCD.
step2: Select the Data Register by making RS high.
step3: Select Write operation making RW low.
step4: Send a High-to-Low pulse on Enable PIN with some delay_us.

The timings are similar as above only change is that RS is made high for selecting Data register.

	/* Function to send the data to GLCD */
	void Glcd_DataWrite(char dat)
	{
	sendByte(dat); //Send the data
	GlcdControlBusPort \|= (1<<GLCD_RS); // Send HIGH pulse on RS pin for selecting data register
	GlcdControlBusPort &= ~(1<<GLCD_RW); // Send LOW pulse on RW pin for Write operation
	LcdControlBusPort \|= (1<<GLCD_EN); // Generate a High-to-low pulse on EN pin
	delay(1000);
	GlcdControlBusPort &= ~(1<<GLCD_EN);

	delay(10000);
	}

view raw glcd_dataWrite.c hosted with ❤ by GitHub

Code Example

Example 1

Let's start with displaying some text.

	#include<lpc17xx.h>

	/* Configure the data bus and Control bus as per the hardware connection */
	#define GlcdDataBusPort LPC_GPIO1->FIOPIN
	#define GlcdControlBusPort LPC_GPIO2->FIOPIN

	#define GlcdDataBusDirnReg LPC_GPIO1->FIODIR
	#define GlcdCtrlBusDirnReg LPC_GPIO2->FIODIR


	#define GLCD_D0 20
	#define GLCD_D1 21
	#define GLCD_D2 22
	#define GLCD_D3 23
	#define GLCD_D4 24
	#define GLCD_D5 25
	#define GLCD_D6 26
	#define GLCD_D7 27

	#define GLCD_RS 0
	#define GLCD_RW 1
	#define GLCD_EN 2


	/* Masks for configuring the DataBus and Control Bus direction */
	#define PortDataBusConfig ((1<<GLCD_D0)\|(1<<GLCD_D1)\|(1<<GLCD_D2)\|(1<<GLCD_D3)\|(1<<GLCD_D4)\|(1<<GLCD_D5)\|(1<<GLCD_D6)\|(1<<GLCD_D7))
	#define PortCtrlBusConfig ((1<<GLCD_RS)\|(1<<GLCD_RW)\|(1<<GLCD_EN))
	#define GLCD_dataBusMask ((1<<GLCD_D0)\|(1<<GLCD_D1)\|(1<<GLCD_D2)\|(1<<GLCD_D3)\|(1<<GLCD_D4)\|(1<<GLCD_D5)\|(1<<GLCD_D6)\|(1<<GLCD_D7))


	/* local function to generate some delay */
	void delay(int cnt)
	{
	int i;
	for(i=0;i<cnt;i++);
	}


	/* Function send a complete byte on the Data bus */
	void sendByte(char byte)
	{
	GlcdDataBusPort&=~(GLCD_dataBusMask); // Clear previous data
	GlcdDataBusPort\|= (((byte >>0x00) & 0x01) << GLCD_D0);
	GlcdDataBusPort\|= (((byte >>0x01) & 0x01) << GLCD_D1);
	GlcdDataBusPort\|= (((byte >>0x02) & 0x01) << GLCD_D2);
	GlcdDataBusPort\|= (((byte >>0x03) & 0x01) << GLCD_D3);
	GlcdDataBusPort\|= (((byte >>0x04) & 0x01) << GLCD_D4);
	GlcdDataBusPort\|= (((byte >>0x05) & 0x01) << GLCD_D5);
	GlcdDataBusPort\|= (((byte >>0x06) & 0x01) << GLCD_D6);
	GlcdDataBusPort\|= (((byte >>0x07) & 0x01) << GLCD_D7);
	}


	/* Function to send the command to Glcd */
	void Glcd_CmdWrite(char cmd)
	{
	sendByte(cmd); //Send the Command
	GlcdControlBusPort &= ~(1<<GLCD_RS); // Send LOW pulse on RS pin for selecting Command register
	GlcdControlBusPort &= ~(1<<GLCD_RW); // Send LOW pulse on RW pin for Write operation
	GlcdControlBusPort \|= (1<<GLCD_EN); // Generate a High-to-low pulse on EN pin
	delay(1000);
	GlcdControlBusPort &= ~(1<<GLCD_EN);

	delay(10000);
	}


	/* Function to send the data to Glcd */
	void Glcd_DataWrite(char dat)
	{
	sendByte(dat); //Send the data
	GlcdControlBusPort \|= (1<<GLCD_RS); // Send HIGH pulse on RS pin for selecting data register
	GlcdControlBusPort &= ~(1<<GLCD_RW); // Send LOW pulse on RW pin for Write operation
	GlcdControlBusPort \|= (1<<GLCD_EN); // Generate a High-to-low pulse on EN pin
	delay(1000);
	GlcdControlBusPort &= ~(1<<GLCD_EN);

	delay(10000);
	}

	void Glcd_SelectPage0()
	{
	GlcdControlBusPort \|= (1<<GLCD_CS1);
	GlcdControlBusPort &= ~(1<<GLCD_CS2);
	}

	void Glcd_SelectPage1()
	{
	GlcdControlBusPort \|= (1<<GLCD_CS2);
	GlcdControlBusPort &= ~(1<<GLCD_CS1);
	}

	void main()
	{
	char i,a[]={"Good morning!"};
	SystemInit(); //Clock and PLL configuration

	GlcdDataBusDirnReg = PortDataBusConfig; // Configure all the Glcd pins as output
	GlcdCtrlBusDirnReg = PortCtrlBusConfig;

	/* Select the Page0/Page1 and turn ON the GLCD */
	Glcd_SelectPage0();
	Glcd_CmdWrite(0x3f);
	Glcd_SelectPage1();
	Glcd_CmdWrite(0x3f);
	DELAY_ms(10);

	/* Select the Page0/Page1 and Enable the GLCD */
	Glcd_SelectPage0();
	Glcd_CmdWrite(0xc0);
	Glcd_SelectPage1();
	Glcd_CmdWrite(0xc0);

	Glcd_SelectPage0();
	Glcd_CmdWrite(0xB8); // Move the cursor to first line
	Glcd_CmdWrite(0x40); // Move the cursor to beginning of line

	Glcd_DataWrite('H');
	Glcd_DataWrite('e');
	Glcd_DataWrite('l');
	Glcd_DataWrite('l');
	Glcd_DataWrite('o');
	Glcd_DataWrite(' ');

	Glcd_SelectPage1();

	Glcd_DataWrite('w');
	Glcd_DataWrite('o');
	Glcd_DataWrite('r');
	Glcd_DataWrite('l');
	Glcd_DataWrite('d');

	Glcd_SelectPage0();
	Glcd_CmdWrite(0xB9); // Move the cursor to second line
	Glcd_CmdWrite(0x40); // Move the cursor to beginning of line

	for(i=0;a[i]!=0;i++)
	{
	Glcd_DataWrite(a[i]);
	}

	while(1);
	}

view raw lpc1768_glcd.c hosted with ❤ by GitHub

Using Explore Embedded Libraries

In the above example we just discussed how to interface Graphics Lcd.
Once you know the working of GLCD, you can directly use the ExploreEmbedded libraries to play around with your GLCD.
For that you need to include the glcd.c/glcd.h and the associated files(delay/stdutils).
The below sample code shows how to use the already available GLCD functions.

Refer this link for more info on GLCD libraries.

	#include<lpc17xx.h>
	#include "glcd.h" //User defined GLCD library which contains the lcd routines
	#include "delay.h" //User defined library which contains the delay routines


	void main()
	{
	SystemInit(); //Clock and PLL configuration

	/* Setup/Map the controller pins for LCD operation
	CS1 CS2 RS RW EN D0 D1 D2 D3 D4 D5 D6 D7 */
	GLCD_SetUp(P2_0,P2_1,P2_2,P2_3,P2_4,P1_20,P1_21,P1_22,P1_23,P1_24,P1_25,P1_26,P1_27);

	/* Initialize GLCD before use */
	GLCD_Init();

	while(1)
	{
	/scroll the message on line1 /
	GLCD_Clear();
	GLCD_ScrollMessage(1," Program to demonstrate the ExploreEmbedded Lib Usage");

	GLCD_Clear();
	GLCD_Printf("Hello, World \nGood Morning");
	DELAY_sec(3);

	GLCD_Clear();
	GLCD_Printf("DecNum:%4d",1234);
	GLCD_Printf("\nHexNum:%4x",0xABCD);
	DELAY_sec(3);

	GLCD_Clear();
	GLCD_Printf("16-bit Bin:1234");
	GLCD_GoToNextLine();
	GLCD_Printf("%16b",0x1234);
	DELAY_sec(3);
	}
	}

view raw lpc1768_glcd_UsngLib.c hosted with ❤ by GitHub

Explore Embedded Graphics Library

GLCD_SetDot ()

Defination

void GLCD_SetDot ( uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_color_u8 )

Input Arguments

var_x_u8 : x coordinate of left side end point of line ( 0 to 127 )
var_y_u8 : y coordinate of left side end point of line ( 0 to 63 )
var_color_u8 : color of pixels ( 0 or 1 )

Return Value

none

Description

This function is used to draw a dot

Usage

	uint8_t x, y;

	x = 0;
	for ( y=0; y<64; y++ )
	{
	GLCD_SetDot(x,y,color);
	x = x + y;
	}

view raw GLCD_SetDot.c hosted with ❤ by GitHub

Output

GLCD_DrawHoriLine()

Defination

void GLCD_DrawHoriLine(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_length_u8,uint8_t var_color_u8)

Input Arguments

var_x_u8 : x coordinate of left side end point of line ( 0 to 127 )
var_y_u8 : y coordinate of left side end point of line ( 0 to 63 )
var_length_u8: length of line
var_color_u8 : color of pixels ( 0 or 1)

Return Value

none

Description

This function is used to draw horizontial line.

Usage

	uint8_t x, y, length;
	x=40;
	y=5;
	length=100;
	while(length)
	{
	GLCD_DrawHoriLine(x,y,length,1);
	length -= 10;
	x += 5;
	y += 5;
	}

view raw GLCD_DrawHoriLine.c hosted with ❤ by GitHub

Output

GLCD_DrawVertLine()

Defination

void GLCD_DrawVertLine(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_length_u8,uint8_t var_color_u8)

Input Arguments

var_x_u8 : x coordinate of left side end point of line ( 0 to 127 )
var_y_u8 : y coordinate of left side end point of line ( 0 to 63 )
var_length_u8: length of line
var_color_u8 : color of pixels ( 0 or 1 )

Return Value

none

Description

This function is used to draw vertical line.

Usage

	uint8_t x,y,length;
	x=40;
	y=5;
	length=60;
	while(length)
	{
	GLCD_DrawVertLine(x,y,length,1);
	length -= 10;
	x += 5;
	y += 5;
	}

view raw GLCD_DrawVertLine.c hosted with ❤ by GitHub

Output

GLCD_DrawLine()

Defination

void GLCD_DrawLine ( uint8_t var_x1_u8, uint8_t var_y1_u8, uint8_t var_x2_u8, uint8_t var_y2_u8, uint8_t var_color_u8)

Input Arguments

var_x1_u8 : x coordinate of end point of line (0 to 127)
var_y1_u8 : y coordinate of end point of line (0 to 63)
var_x2_u8: x coordinate of other end point of line
var_y2_u8: y coordinate of other end point of line
var_color_u8 : color of pixels ( 0 or 1 )

Return Value

none

Description

This function is used to draw line.

Usage


	GLCD_DrawLine(60,0,120,30,1);
	GLCD_DrawLine(120,30,60,60,1);
	GLCD_DrawLine(60,60,0,30,1);
	GLCD_DrawLine(0,30,60,0,1);

view raw GLCD_DrawLine.c hosted with ❤ by GitHub

Output

GLCD_DrawRect()

Defination

void GLCD_DrawRect(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_width_u8, uint8_t var_height_u8, uint8_t var_color_u8)

Input Arguments

var_x_u8 : x coordinate of top left side vertex of rectangle (0 to 127)
var_y_u8 : y coordinate of top left side vertex of rectangle (0 to 63)
var_width_u8 : width of rectangle
var_height_u8 : height of rectangle
var_color_u8 : color of pixels ( 0 or 1 )

Return Value

none

Description

This function is used to draw rectangle.

Usage


	GLCD_DrawRect(18,8,80,50,1);
	GLCD_DrawRect(28,18,60,30,1);
	GLCD_DrawRect(38,28,40,10,1);

view raw GLCD_DrawRect.c hosted with ❤ by GitHub

Output

GLCD_DrawRoundRect()

Defination

void GLCD_DrawRoundRect(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_width_u8, uint8_t var_height_u8, var_radius_u8, uint8_t var_color_u8)

Input Arguments

var_x_u8 : x coordinate of top left side vertex of rectangle ( 0 to 127 )
var_y_u8 : y coordinate of top left side vertex of rectangle ( 0 to 63 )
var_width_u8 : width of rectangle
var_height_u8 : height of rectangle
var_radius_u8 : radius of circular part at corner
var_color_u8 : color of pixels ( 0 or 1 )

Return Value

none

Description

This function is used to draw round rectangle.

Usage

	GLCD_DrawRoundRect(18,8,80,50,15,1);
	GLCD_DrawRoundRect(28,18,60,30,10,1);
	GLCD_DrawRoundRect(38,28,40,10,5,1);

view raw GLCD_DrawRoundRect.c hosted with ❤ by GitHub

Output

GLCD_DrawFillRect()

Defination	void GLCD_DrawFillRect(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_width_u8, uint8_t var_height_u8, uint8_t var_color_u8)
Input Arguments	var_x_u8 : x coordinate of top left side vertex of rectangle (0 to 127) var_y_u8 : y coordinate of top left side vertex of rectangle (0 to 63) var_width_u8 : width of rectangle var_height_u8 : height of rectangle var_color_u8 : color of pixels ( 0 or 1 )
Return Value	none
Description	This function is used to draw filled rectangle.
Usage	GLCD_DrawFillRect(23,13,80,40,1);
Output

GLCD_InvertRect()

Defination	void GLCD_InvertRect(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_width_u8, uint8_t var_height_u8)
Input Arguments	var_x_u8 : x coordinate of top left side vertex of rectangle (0 to 127) var_y_u8 : y coordinate of top left side vertex of rectangle (0 to 63) var_width_u8 : width of rectangle var_height_u8 : height of rectangle
Return Value	none
Description	This function is used to invert the selected rectangular area
Usage	GLCD_InvertRect(18,8,80,50); GLCD_InvertRect(28,18,60,30); GLCD_InvertRect(38,28,40,10);
Output

GLCD_DrawCircle()

Defination	void GLCD_DrawCircle(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_radius_u8, uint8_t var_color_u8)
Input Arguments	var_x_u8 : x coordinate of center of circle (0 to 127) var_y_u8 : y coordinate of center of circle (0 to 63) var_radius_u8 : radius of circle var_color_u8 : color of pixels ( 0 or 1 )
Return Value	none
Description	This function is used to draw circle.
Usage	GLCD_DrawCircle(60,30,30,1); GLCD_DrawCircle(60,30,20,1); GLCD_DrawCircle(60,30,10,1);
Output

GLCD_DrawFillCircle()

Defination	void GLCD_DrawFillCircle(uint8_t var_x_u8, uint8_t var_y_u8, uint8_t var_radius_u8, uint8_t var_color_u8)
Input Arguments	var_x_u8 : x coordinate of center of circle (0 to 127) var_y_u8 : y coordinate of center of circle (0 to 63) var_radius_u8 : radius of circle var_color_u8 : color of pixels ( 0 or 1 )
Return Value	none
Description	This function is used to draw filled circle.
Usage	GLCD_DrawFillCircle(60,30,30,1);
Output

GLCD_DisplayVerticalGraph()

Defination	void GLCD_DisplayVerticalGraph(uint8_t var_barGraphNumber_u8, uint8_t var_percentageValue_u8)
Input Arguments	var_barGraphNumber_u8 : position of bar ( 0 to 3 ) var_percentageValue_u8 : value of the bar in percentage
Return Value	This function displays bar graph in vertical direction
Description	This function is used to draw filled circle.
Usage	GLCD_DisplayVerticalGraph(0,45); GLCD_DisplayVerticalGraph(1,50); GLCD_DisplayVerticalGraph(2,82); GLCD_DisplayVerticalGraph(3,74);
Output

GLCD_DisplayHorizontalGraph()

Defination	void GLCD_DisplayHorizontalGraph(uint8_t var_barGraphNumber_u8, uint8_t var_percentageValue_u8)
Input Arguments	var_barGraphNumber_u8 : position of bar ( 0 to 3 ) var_percentageValue_u8 : value of the bar in percentage
Return Value	This function displays bar graph in horizontial direction
Description	This function is used to draw filled circle.
Usage	GLCD_DisplayHorizontalGraph(0,45); GLCD_DisplayHorizontalGraph(1,50); GLCD_DisplayHorizontalGraph(2,82); GLCD_DisplayHorizontalGraph(3,74);
Output

Lots of things are there which you would like to do with GLCD and we will cover it in the future tutorials. For now, you don't forget to comment.

Retrieved from "https://exploreembedded.com/wiki/index.php?title=LPC1768:_GLCD_Interfacing&oldid=7940"

Category:

LPC1768 Tutorials

LPC1768: GLCD Interfacing

Contents

Objective

Schematic

Port Connection

GLCD Operation

Timing Diagram

Steps for Sending Command:

Steps for Sending Data:

Code Example

Example 1

Using Explore Embedded Libraries

Explore Embedded Graphics Library

GLCD_SetDot ()

GLCD_DrawHoriLine()

GLCD_DrawVertLine()

GLCD_DrawLine()

GLCD_DrawRect()

GLCD_DrawRoundRect()

GLCD_DrawFillRect()

GLCD_InvertRect()

GLCD_DrawCircle()

GLCD_DrawFillCircle()

GLCD_DisplayVerticalGraph()

GLCD_DisplayHorizontalGraph()