This is a port of Henning Kralsen's UTFT library for Arduino/chipKIT to mbed, refactored to make full use of C++ inheritance and access control, in order to reduce work when implementing new drivers and at the same time make the code more readable and easier to maintain. As of now supported are SSD1289 (16-bit interface), HX8340-B (serial interface) and ST7735 (serial interface). Drivers for other controllers will be added as time and resources to acquire the displays to test the code permit.

Dependents:   test SDCard capstone_display capstone_display_2 ... more

TFTLCD Library

NOTE (2013-03-25) Tested with both mbed LPC1768 and Freedom KL25Z. -todor

A TFT LCD driver library, which at the moment provides support for the following display controllers: HX8340-B (serial interface), SSD1289 (16-bit interface), ST7735-R (serial interface), ILI9325/ILI9328 (16-bit interface).

As I am acquiring and testing out new displays, I decided to combine all ported drivers into one library as with the original work done by Henning. However I also had as a goal to make the code maintenance and readability easier/better, so the code has been heavily refactored to make full use of C++ facilities as inheritance and access control. I extracted the common pieces of code into a base class, which every driver inherits and only the controller-specific side is provided in the actual driver - things like initialization, addressing, data transfer, etc.

Another nice extension is that the display's backlight can now be controlled through the driver. Either a simple on/off method of control could be selected, or the brightness can be set through use of PWM (the latter placing some restrictions on which pins can be used for this, as mbed offers hardware PWM on only 6 pins).

I also plan to add support for touch screens as part of the library. The goal is to grow this piece of software into a lightweight graphics widgets library, which can be used to construct control screens with buttons or menus in a speedy and intuitive way.

Changes

2013-07-21

  • Fixed the sleep/wake-up functions of the ILI9328 driver.

2013-06-15

  • Added driver for ILI9328 (works with ILI9325) controller, 16-bit data bus. Screen rotation works as usual with the TFTLCD library, but for now only RGB565 color depth is working and you can use both 65K and 262K color space with this driver. But for some reason the sleep function is not behaving as expected; I am working on this.
  • This is only on my to-do list for now - haven't really had the time yet - but I am going to refactor the library a bit to allow use of GPIO ports for data transfers instead of DigitalOut: faster and cleaner that way. For those who are using it already in a working design and cannot repurpose the pins anymore, the current way it's working will still be available; I am hoping not to tear up the public interfaces of the library (... too much). Anyway, since I am at it, I will also try to add support for multiple bus interfaces to drivers that support it (i.e. both 8bit and 16bit use of ILI932x or SSD1289). Thought this might be a good place to give you guys the heads-up.

2013-01-25

  • Replaced all existing fonts from the UTFT library with the free Terminus font. Two different sizes are provided: 8x12 pixels and 16x28 pixels. I found the old fonts not so good looking and then they supported only the ASCII codes in the range 30 (space) to 126 (the tilde ). The 7segment font didn't even implement anything else than the numbers from 0 to 9 - so it was unusable for anything (one couldn't even display the time or date as it lacked the colon [:] or the period [.] or the slash [/] or the space [ ] characters). So I completely revamped the fonts and added Terminus as the new default with its 2 sizes. Further more I added in both sizes most of the characters up to ASCII code 255. For any code not in there, the space character is substituted. In the case, when you already have provided your own fonts, please have a look at the API changes in the files <terminus.h> and <terminus.cpp>: I promise you whatever time you spent designing your own font, it is not wasted; you merely need to add a second array, which describes which ASCII codes are available in your font, and their byte offset in the original character bitmap array; and a struct to tie all parts together and describe the character size. I am sorry for breaking the old API, but you will like the change and new options it brings you. Now you can insert any char above 127 up to code 255 (if available, of course) with its hex representation, e.g displaying the current temperature would look something like 85\xB0 F or 26\xB0 C (the space in between degree and F or C is needed because both F and C are used in hex numbers, so \xB0F is interpreted as ASCII code 2831 instead of ASCII code 176, followed by the temperature scale denomination; if you insist on avoiding the space, you could write 85\xB0\x46 which will be displayed correctly as 85°F). You can either look up the ASCII code you need on Google or Bing, or just look at what's available - how it looks and its hex value - in the comments in <terminus.cpp>.
  • Added PWM backlight control. If you intend to use this, please make sure that control pin is either one of p21, p22, p23, p24, p25, or p26, as only they support hardware PWM. Please be aware that the mbed pins do not have much juice behind them, so if your display's backlight requires a lot of current, you are better off interfacing through as small signal transistor or a MOSFET. For the rest please consult the updated Doxygen documentation. NOTE The addition of PWM-controlled backlight will not break your existing code, the new options have default values, which initialize the used driver to behave as prior to PWM. Only if you want to use the new feature, some changes need to be made. The PWM is configured to be 120Hz (period of 8.33 milliseconds), in order to avoid noticeable flicker in the backlight. If in your opinion this value is too fine, then you can reduce the frequency in the LCD constructor in <lcd_base.cpp> by increasing the period value. My recommendation is to avoid frequencies lower than 60Hz.

2012-12-21

  • Internal-only changes in the way drivers transmit colors - done to simplify the bitmap drawing routines; client API remains unchanged.

2012-12-12

  • Added the driver for the ST7735 display controller.
  • Added the RGB18 color mode: choose between 16-bit (65K distinct colors) and 18-bit (262K distinct colors) color space [supported by all drivers]. NOTE This feature requires the image drawing functions to be changed, in order to account for differences between configured display color depth and the color depth of the image. Please review the API docs, in particular the new type bitmap_t and the DrawBitmap functions.
  • Changed display rotation to be achieved through the correspondent settings in the respective controller registers: no more software translation between width and height in different display orientations.
  • Extended the orientation options: PORTRAIT (top line to 12 o'clock/upright) and LANDSCAPE (top line to 9 o'clock) positions are the old options, PORTRAIT_REV (top line to 6 o'clock/upside-down) and LANDSCAPE_REV (top line to 3 o'clock) are the new orientations.
  • Added more pre-defined colors: available now are COLOR_BLACK, COLOR_WHITE, COLOR_RED, COLOR_GREEN, COLOR_BLUE, COLOR_CYAN, COLOR_MAGENTA and COLOR_YELLOW.

TODO

  • Finish implementing PWM-controlled backlight (current-sink configuration).
  • Add a driver for the HX8352-A controller (ITDB02-3.2WD 16:9 240x400 pixel resolution display).

How to Use

The code is documented, so please review the API docs. There is a simple example to get you started...

Revision:
12:d0978272a340
Parent:
11:aeceefc5f9f2
Child:
19:eb27effb8c07
--- a/lcd_base.h	Tue Dec 11 16:50:09 2012 +0000
+++ b/lcd_base.h	Tue Dec 11 18:11:14 2012 +0000
@@ -39,14 +39,16 @@
 #endif
 
 /** \def RGB(r,g,b)
- *  \brief Creates a RGB-565 color value.
+ *  \brief Creates a RGB color from distinct bytes for the red, green and blue components.
  *
  * Displays which use 16 bits to assign colors to a specific pixel, use
  * 5 bits for the red component, 6 bits for the green component and 5
- * bits for the blue component.  This macro converts the 3 full-size
- * RGB bytes into one 16-bit RGB-565 value.
+ * bits for the blue component.  Displays which have 18-bit color depth
+ * use 6 bits for red, 6 bits for green and 6 bits for blue component.
+ * This macro preserves the full 24-bit color depth, but it is the responsibility
+ * of the respective driver to convert the color value to the correct format.
  */
-#define RGB( r, g, b )          ( ( ( ( r ) & 248 ) | ( ( g ) >> 5 ) ) << 8 ) | ( ( ( ( g ) & 28 ) << 3 ) | ( ( b ) >> 3 ) )
+#define RGB( r, g, b )          ( ( r ) << 16 ) | ( ( g ) << 8 ) | ( b )
 /** \def COLOR_BLACK
  *  \brief Shorthand for RGB( 0, 0, 0 ).
  */
@@ -73,8 +75,10 @@
  */
 enum Orientation_enum
 {
-    PORTRAIT = 0, /**< Display height is bigger than its width. */ 
-    LANDSCAPE = 1, /**< Display width is bigger than its height. */
+    PORTRAIT = 0, /**< Display height is bigger than its width. View at 12 o'clock. */ 
+    LANDSCAPE = 1, /**< Display width is bigger than its height. View at 9 o'clock. */
+    PORTRAIT_REV = 2, /**< Display height is bigger than its width. View at 6 o'clock. */
+    LANDSCAPE_REV = 3, /**< Display width is bigger than its height. View at 3 o'clock. */
 };
 /** \typedef orientation_t
  *  \brief Convenience shortcut for display orientation.
@@ -125,6 +129,21 @@
  */
 typedef struct Font_struct font_metrics_t;
 
+/** \struct Bitmap_struct
+ *  \brief Describes an image.
+ */
+struct Bitmap_struct
+{
+    colordepth_t Format; /**< Color depth of the image. */
+    unsigned short Width; /**< Width of the image in pixels. */
+    unsigned short Height; /**< Height of the image in pixels. */
+    const void* PixelData; /**< Image pixel data. */
+};
+/** \typedef bitmap_t
+ *  \brief Convenience shortcut bitmap type.
+ */
+typedef struct Bitmap_struct bitmap_t;
+
 
 /** Base class for LCD implementations.
  *
@@ -148,8 +167,9 @@
      * This function is controller-specific and needs to be implemented
      * separately for each available display.
      * \param oritentation The display orientation, landscape is default.
+     * \param colors The correct color depth to use for the pixel data.
      */
-    virtual void Initialize( orientation_t orientation ) = 0;
+    virtual void Initialize( orientation_t orientation, colordepth_t colors ) = 0;
     
     /** Puts the display to sleep.
      *
@@ -187,10 +207,10 @@
      * in place, the new setting will be used for that single operation only and
      * will not change this value.
      *
-     * \param color The color to be used. The value must be in RGB-565 format.
+     * \param color The color to be used (24-bit color depth).
      * \sa #RGB(r,g,b)
      */
-    virtual void SetForeground( unsigned short color = COLOR_WHITE );
+    virtual void SetForeground( unsigned int color = COLOR_WHITE );
     
     /** Set the background color for painting.
      *
@@ -199,10 +219,10 @@
      * when the function is called, the new value will be used only for this
      * single call and will not change this setting.
      *
-     * \param color The background color as RGB-565 value.
+     * \param color The background color (24-bit color depth).
      * \sa #RGB(r,g,b)
      */
-    virtual void SetBackground( unsigned short color = COLOR_BLACK );
+    virtual void SetBackground( unsigned int color = COLOR_BLACK );
     
     /** Sets the font to be used for painting of text on the screen.
      * \param font A pointer to the font data.
@@ -240,7 +260,7 @@
      *
      * \param x The horizontal offset of the pixel from the upper left corner of the screen.
      * \param y The vertical offset of the pixel from the upper left corner of the screen.
-     * \param color The color to be used. Must be in RGB-565 format, or -1 for background and -2 for foreground color.
+     * \param color The color to be used. Use a custom color, or -1 for background and -2 for foreground color.
      */
     virtual void DrawPixel( unsigned short x, unsigned short y, int color = -2 );
     
@@ -250,7 +270,7 @@
      * \param y1 Vertical offset of the beginning point of the line.
      * \param x2 Horizontal offset of the end point of the line.
      * \param y2 Verical offset of the end point of the line.
-     * \param color The color to use for painting, in RGB-565 format, or -1 for background, or -2 for foreground.
+     * \param color The color to use for painting, or -1 for background, or -2 for foreground.
      */
     virtual void DrawLine( unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, int color = -2 );
     
@@ -260,7 +280,7 @@
      * \param y1 The vertical offset of the beginning point of one of the rectangle's diagonals.
      * \param x2 The horizontal offset of the end point of the same of the rectangle's diagonals.
      * \param y2 The vertical offset of the end point of the same of the rectangle's diagonals.
-     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color in RGB-565 format.
+     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color.
      */
     virtual void DrawRect( unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, int color = -2 );
     
@@ -270,7 +290,7 @@
      * \param y1 The vertical offset of the beginning point of one of the rectangle's diagonals.
      * \param x2 The horizontal offset of the end point of the same of the rectangle's diagonals.
      * \param y2 The vertical offset of the end point of the same of the rectangle's diagonals.
-     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color in RGB-565 format.
+     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color.
      */
     virtual void DrawRoundRect( unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, int color = -2 );
     
@@ -280,7 +300,7 @@
      * \param y1 The vertical offset of the beginning point of one of the rectangle's diagonals.
      * \param x2 The horizontal offset of the end point of the same of the rectangle's diagonals.
      * \param y2 The vertical offset of the end point of the same of the rectangle's diagonals.
-     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color in RGB-565 format.
+     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color.
      */
     virtual void FillRect( unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, int color = -2 );
     
@@ -290,7 +310,7 @@
      * \param y1 The vertical offset of the beginning point of one of the rectangle's diagonals.
      * \param x2 The horizontal offset of the end point of the same of the rectangle's diagonals.
      * \param y2 The vertical offset of the end point of the same of the rectangle's diagonals.
-     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color in RGB-565 format.
+     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color.
      */
     virtual void FillRoundRect( unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, int color = -2 );
     
@@ -299,7 +319,7 @@
      * \param x The offset of the circle's center from the left edge of the screen.
      * \param y The offset of the circle's center from the top edge of the screen.
      * \param radius The circle's radius.
-     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color in RGB-565 format.
+     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color.
      */
     virtual void DrawCircle( unsigned short x, unsigned short y, unsigned short radius, int color = -2 );
     
@@ -308,7 +328,7 @@
      * \param x The offset of the circle's center from the left edge of the screen.
      * \param y The offset of the circle's center from the top edge of the screen.
      * \param radius The circle's radius.
-     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color in RGB-565 format.
+     * \param color The color to use for painting. -1 indicated background, -2 foreground, or custom color.
      */
     virtual void FillCircle( unsigned short x, unsigned short y, unsigned short radius, int color = -2 );
     
@@ -333,13 +353,11 @@
      * http://henningkarlsen.com/electronics/library.php?id=52
      *
      * \param x Horizontal offset of the first pixel of the image.
-     * \param y Vertical offset of the first pixel of the image
-     * \param sx Width of the image.
-     * \param sy Height of the image.
-     * \param imgPixelData Image pixel array.
+     * \param y Vertical offset of the first pixel of the image.
+     * \param img Image data pointer.
      * \param scale A value of 1 will produce an image with its original size, while a different value will scale the image.
      */
-    virtual void DrawBitmap( unsigned short x, unsigned short y, unsigned short sx, unsigned short sy, const unsigned short* imgPixelData, unsigned char scale = 1 );
+    virtual void DrawBitmap( unsigned short x, unsigned short y, const bitmap_t* img, unsigned char scale = 1 );
     
     /** Draw an image on the screen.
      *
@@ -350,15 +368,13 @@
      * http://henningkarlsen.com/electronics/library.php?id=52
      *
      * \param x Horizontal offset of the first pixel of the image.
-     * \param y Vertical offset of the first pixel of the image
-     * \param sx Width of the image.
-     * \param sy Height of the image.
-     * \param imgPixelData Image pixel array.
+     * \param y Vertical offset of the first pixel of the image.
+     * \param img Image data pointer.
      * \param deg Angle to rotate the image before painting on screen, in degrees.
      * \param rox
      * \param roy
      */
-    virtual void DrawBitmap( unsigned short x, unsigned short y, unsigned short sx, unsigned short sy, const unsigned short* imgPixelData, unsigned short deg, unsigned short rox, unsigned short roy );
+    virtual void DrawBitmap( unsigned short x, unsigned short y, const bitmap_t* img, unsigned short deg, unsigned short rox, unsigned short roy );
     
 protected:
     /** Creates an instance of the class.
@@ -434,10 +450,10 @@
     /** Sets the color of the pixel at the address pointer of the controller.
      *
      * This function is to be provided by each implementation separately in
-     * order to account for different color depth used by the controller.
+     * order to account for different color depths used by the controller.
      * \param color The color of the pixel.
      */
-    virtual void SetPixelColor( unsigned short color ) = 0;
+    virtual void SetPixelColor( unsigned int color ) = 0;
     
     /** Draws a horizontal line.
      *
@@ -448,7 +464,7 @@
      * \param y Y coordinate of the starting point of the line.
      * \param len Length of the line.
      * \param color The color to use to draw the line. By default the global foreground color is used ( -2 ),
-     *              -1 switches to the default background color, or any other RGB-565 color can be used.
+     *              -1 switches to the default background color, or any custom color can be used.
      */
     virtual void DrawHLine( unsigned short x, unsigned short y, unsigned short len, int color = -2 );
     
@@ -461,7 +477,7 @@
      * \param y Y coordinate of the starting point of the line.
      * \param len Height of the line.
      * \param color The color to use to draw the line. By default the global foreground color is used ( -2 ),
-     *              -1 switches to the default background color, or any other RGB-565 color can be used.
+     *              -1 switches to the default background color, or any custom color can be used.
      */
     virtual void DrawVLine( unsigned short x, unsigned short y, unsigned short len, int color = -2 );
     
@@ -471,9 +487,9 @@
      * \param x X coordinate of the character position.
      * \param y Y coordinate of the character position.
      * \param fgColor Foreground color for drawing. By default the global foreground color is used ( -2 ),
-     *                -1 switches to the default background color, or any other RGB-565 color can be used.
+     *                -1 switches to the default background color, or any custom color can be used.
      * \param bgColor Background color for drawing. By default the global background color is used ( -1 ),
-     *                -2 switches to the default foreground color, or any other RGB-565 color can be used.
+     *                -2 switches to the default foreground color, or any custom color can be used.
      */
     virtual void PrintChar( char c, unsigned short x, unsigned short y, int fgColor = -2, int bgColor = -1 );
     
@@ -484,9 +500,9 @@
      * \param y Y coordinate of the character position.
      * \param pos Position of the character in the string from which it originates (used to rotate a whole string).
      * \param fgColor Foreground color for drawing. By default the global foreground color is used ( -2 ),
-     *                -1 switches to the default background color, or any other RGB-565 color can be used.
+     *                -1 switches to the default background color, or any custom color can be used.
      * \param bgColor Background color for drawing. By default the global background color is used ( -1 ),
-     *                -2 switches to the default foreground color, or any other RGB-565 color can be used.
+     *                -2 switches to the default foreground color, or any custom color can be used.
      * \param deg The angle at which to rotate. 
      */
     virtual void RotateChar( char c, unsigned short x, unsigned short y, int pos, int fgColor = -2, int bgColor = -1, unsigned short deg = 0 );
@@ -495,7 +511,8 @@
     unsigned short  _disp_width, _disp_height;
     DigitalOut      _lcd_pin_cs, _lcd_pin_rs, _lcd_pin_reset;
     orientation_t   _orientation;
-    unsigned short  _foreground, _background;
+    colordepth_t    _colorDepth;
+    unsigned int    _foreground, _background;
     font_metrics_t  _font;
 };