ST7735 Controllers

This section covers GLCD devices that use the ST7735 graphics controller. The ST7735 is a single-chip controller/driver for 262K-color, graphic type TFT-LCD.

The Great Cow BASIC constants shown below control the configuration of the ILI9340 controller.    Great Cow BASIC supports an 8 bit bus connectivity. The 8 bit must be a single port of consective bits - this is shown in the tables below.

To use the ST7735 driver simply include the following in your user code. This will initialise the driver.

    #include <glcd.h>
    #DEFINE GLCD_TYPE GLCD_TYPE_ST7735

    'Pin mappings for ST7735
    #define GLCD_DC     porta.0           'example port setting
    #define GLCD_CS     porta.1           'example port setting
    #define GLCD_RESET  porta.2           'example port setting
    #define GLCD_DI     porta.3           'example port setting
    #define GLCD_DO     porta.4           'example port setting
    #define GLCD_SCK    porta.5           'example port setting

The Great Cow BASIC constants for control display characteristics are shown in the table below.

Constants Controls Options

GLCD_TYPE

GLCD_TYPE_ST7735

 

GLCD_DATA_PORT

Not Available for this controller.

Not applicable.

GLCD_DC

Specifies the output pin that is connected to Data/Command IO pin on the GLCD.

Required

GLCD_CS

Specifies the output pin that is connected to Chip Select (CS) on the GLCD.

Required

GLCD_Reset

Specifies the output pin that is connected to Reset pin on the GLCD.

Required

GLCD_DI

Specifies the output pin that is connected to Data In (GLCD out) pin on the GLCD.

Required

GLCD_D0

Specifies the output pin that is connected to Data Out (GLCD in) pin on the GLCD.

Required

GLCD_SLK

Specifies the output pin that is connected to Clock (CLK) pin on the GLCD.

Required

The Great Cow BASIC constants for control display characteristics are shown in the table below.

Constants Controls Default

GLCD_WIDTH

The width parameter of the GLCD

160
This cannot be changed

GLCD_HEIGHT

The height parameter of the GLCD

128
This cannot be changed

GLCDFontWidth

Specifies the font width of the Great Cow BASIC font set.

6

The Great Cow BASIC commands supported for this GLCD are shown in the table below.   Always review the appropiate library for the latest full set of supported commands.

Command Purpose Example

GLCDCLS

Clear screen of GLCD

GLCDCLS

GLCDPrint

Print string of characters on GLCD using GCB font set

GLCDPrint( Xposition, Yposition, Stringvariable )

GLCDDrawChar

Print character on GLCD using GCB font set

GLCDDrawChar( Xposition, Yposition, CharCode )

GLCDDrawString

Print characters on GLCD using GCB font set

GLCDDrawString( Xposition, Yposition, Stringvariable )

Box

Draw a box on the GLCD to a specific size

Box ( Xposition1, Yposition1, Xposition2, Yposition2, [Optional In LineColour as 0 or 1] )

FilledBox

Draw a box on the GLCD to a specific size that is filled with the foreground colour.

FilledBox (Xposition1, Yposition1, Xposition2, Yposition2, [Optional In LineColour 0 or 1] )

Line

Draw a line on the GLCD to a specific length that is filled with the specific attribute.

Line ( Xposition1, Yposition1, Xposition2, Yposition2, [Optional In LineColour 0 or 1] )

PSet

Set a pixel on the GLCD at a specific position that is set with the specific attribute.

PSet(Xposition, Yposition, Pixel Colour 0 or 1)

GLCDWriteByte

Set a byte value to the controller, see the datasheet for usage.

GLCDWriteByte (LCDByte)

GLCDReadByte

Read a byte value from the controller, see the datasheet for usage.

bytevariable = GLCDReadByte

ST7735_[color]

Specify color as a parameter for many GLCD commands

Color constants for this device are shown in the list below.

Any color can be defined using a valid hexidecimal word value between 0x0000 to 0xFFFF.

   ST7735_BLACK   'hexidecimal value 0x0000
   ST7735_BLUE    'hexidecimal value 0xF800
   ST7735_RED     'hexidecimal value 0x001F
   ST7735_GREEN   'hexidecimal value 0x07E0
   ST7735_CYAN    'hexidecimal value 0xFFE0
   ST7735_MAGENTA 'hexidecimal value 0xF81F
   ST7735_YELLOW  'hexidecimal value 0x07FF
   ST7735_WHITE   'hexidecimal value 0xFFFF

For a ST7735 datasheet, please refer here.

Example:

    ;Chip Settings
    #chip 16F1937,32
    #config Osc = INT, VCAPEN_OFF, MCLRE_ON, PLLEN_ON, CLKOUTEN_OFF

    #include <glcd.h>

    'Defines for ST7735
    #define GLCD_TYPE GLCD_TYPE_ST7735
    'Pin mappings for ST7735
    #define GLCD_DC porta.0
    #define GLCD_CS porta.1
    #define GLCD_RESET porta.2
    #define GLCD_DI porta.3
    #define GLCD_DO porta.4
    #define GLCD_SCK porta.5

    GLCDPrint(0, 0, "Test of the ST7735 Device")
    end

For more help, see GLCDCLS, GLCDDrawChar, GLCDPrint, GLCDReadByte, GLCDWriteByte or Pset

Supported in <GLCD.H>