Intro

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

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.

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.

Code Example

Example 1

Let's start with displaying some text.

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.

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
Return Value	none
Description	This function is used to draw a dot
Usage
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
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
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
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
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
Return Value	none
Description	This function is used to draw round rectangle.
Usage
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.

LPC1768: GLCD Interfacing
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Contents

Intro

Schematic

Port Connection