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.



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


  • 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.


  • 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.


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


  • 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.


  • 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...

Sat Jun 15 05:34:53 2013 +0000
- ported ILI9328 (actually ILI9325D) driver from UTFT; still need to fix screen rotation.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ttodorov 23:eca4414196ca 1 /** \file ili9328.h
ttodorov 23:eca4414196ca 2 * \brief mbed LCD driver for displays with the ILI9328 controller.
ttodorov 23:eca4414196ca 3 * \copyright GNU Public License, v2. or later
ttodorov 23:eca4414196ca 4 *
ttodorov 23:eca4414196ca 5 * This library is based on the Arduino/chipKIT UTFT library by Henning
ttodorov 23:eca4414196ca 6 * Karlsen,
ttodorov 23:eca4414196ca 7 *
ttodorov 23:eca4414196ca 8 * Copyright (C)2010-2012 Henning Karlsen. All right reserved.
ttodorov 23:eca4414196ca 9 *
ttodorov 23:eca4414196ca 10 * Copyright (C)2012-2013 Todor Todorov.
ttodorov 23:eca4414196ca 11 *
ttodorov 23:eca4414196ca 12 * This library is free software; you can redistribute it and/or
ttodorov 23:eca4414196ca 13 * modify it under the terms of the GNU Lesser General Public
ttodorov 23:eca4414196ca 14 * License as published by the Free Software Foundation; either
ttodorov 23:eca4414196ca 15 * version 2.1 of the License, or (at your option) any later version.
ttodorov 23:eca4414196ca 16 *
ttodorov 23:eca4414196ca 17 * This library is distributed in the hope that it will be useful,
ttodorov 23:eca4414196ca 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
ttodorov 23:eca4414196ca 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
ttodorov 23:eca4414196ca 20 * Lesser General Public License for more details.
ttodorov 23:eca4414196ca 21 *
ttodorov 23:eca4414196ca 22 * You should have received a copy of the GNU Lesser General Public
ttodorov 23:eca4414196ca 23 * License along with this library; if not, write to:
ttodorov 23:eca4414196ca 24 *
ttodorov 23:eca4414196ca 25 * Free Software Foundation, Inc.
ttodorov 23:eca4414196ca 26 * 51 Franklin St, 5th Floor, Boston, MA 02110-1301, USA
ttodorov 23:eca4414196ca 27 *
ttodorov 23:eca4414196ca 28 *********************************************************************/
ttodorov 23:eca4414196ca 29 #ifndef TFTLCD_ILI9328_H
ttodorov 23:eca4414196ca 30 #define TFTLCD_ILI9328_H
ttodorov 23:eca4414196ca 31
ttodorov 23:eca4414196ca 32 #include "lcd_base.h"
ttodorov 23:eca4414196ca 33
ttodorov 23:eca4414196ca 34 #ifdef __cplusplus
ttodorov 23:eca4414196ca 35 extern "C" {
ttodorov 23:eca4414196ca 36 #endif
ttodorov 23:eca4414196ca 37
ttodorov 24:ac6e35658037 38 /** Represents a LCD instance.
ttodorov 24:ac6e35658037 39 *
ttodorov 24:ac6e35658037 40 * This is the utility class, through which the display can be manipulated
ttodorov 24:ac6e35658037 41 * and graphics objects can be shown to the user. A known display, which
ttodorov 24:ac6e35658037 42 * works with this library is the INANBO-T24-ILI9328-V11 - a RGB TFT
ttodorov 24:ac6e35658037 43 * with 240x320 pixels resolution and 65K/262K colors, using 8/16-bit interface.
ttodorov 24:ac6e35658037 44 *
ttodorov 24:ac6e35658037 45 * The display works with a supply voltage of 2.8-3.3 volts for both logic and
ttodorov 24:ac6e35658037 46 * backlight. It can be driven in 8bit or 16bit interface mode. (Current
ttodorov 24:ac6e35658037 47 * version of the driver works only in 16bit mode for now.)
ttodorov 24:ac6e35658037 48 *
ttodorov 24:ac6e35658037 49 * How to use:
ttodorov 24:ac6e35658037 50 * \code
ttodorov 24:ac6e35658037 51 * // include the library, this will also pull in the header for the provided fonts
ttodorov 24:ac6e35658037 52 * #include "ili9328.h"
ttodorov 24:ac6e35658037 53 *
ttodorov 24:ac6e35658037 54 * // prepare the data bus for writing commands and pixel data
ttodorov 24:ac6e35658037 55 * BusOut dataBus( p30, p29, p28, p27, p26, p25, p24, p23, p22, p21, p20, p19, p18, p17, p16, p15 ); // 16 pins
ttodorov 24:ac6e35658037 56 * // create the lcd instance
ttodorov 24:ac6e35658037 57 * ILI9328_LCD lcd( p14, p13, p12, p11, &dataBus ); // control pins and data bus
ttodorov 24:ac6e35658037 58 *
ttodorov 24:ac6e35658037 59 * int main()
ttodorov 24:ac6e35658037 60 * {
ttodorov 24:ac6e35658037 61 * // initialize display - place it in standard portrait mode and set background to black and
ttodorov 24:ac6e35658037 62 * // foreground to white color.
ttodorov 24:ac6e35658037 63 * lcd.Initialize();
ttodorov 24:ac6e35658037 64 * // set current font to the smallest 8x12 pixels font.
ttodorov 24:ac6e35658037 65 * lcd.SetFont( Font8x12 );
ttodorov 24:ac6e35658037 66 * // print something on the screen
ttodorov 24:ac6e35658037 67 * lcd.Print( "Hello, World!", CENTER, 25 ); // align text to center horizontally and use starndard colors
ttodorov 24:ac6e35658037 68 *
ttodorov 24:ac6e35658037 69 * while ( 1 ) { }
ttodorov 24:ac6e35658037 70 * }
ttodorov 24:ac6e35658037 71 *
ttodorov 24:ac6e35658037 72 * \endcode
ttodorov 24:ac6e35658037 73 * \version 0.1
ttodorov 24:ac6e35658037 74 * \author Todor Todorov
ttodorov 24:ac6e35658037 75 */
ttodorov 23:eca4414196ca 76 class ILI9328_LCD : public LCD
ttodorov 23:eca4414196ca 77 {
ttodorov 23:eca4414196ca 78 public:
ttodorov 24:ac6e35658037 79 /** Creates a new instance of the class.
ttodorov 24:ac6e35658037 80 *
ttodorov 24:ac6e35658037 81 * \param CS Pin for the ChipSelect signal.
ttodorov 24:ac6e35658037 82 * \param RESET Pin for the RESET line.
ttodorov 24:ac6e35658037 83 * \param RS Pin for the RS signal.
ttodorov 24:ac6e35658037 84 * \param WR Pin for the WR signal.
ttodorov 24:ac6e35658037 85 * \param DATA_PORT Address of the data bus for transfer of commands and pixel data.
ttodorov 24:ac6e35658037 86 * \param BL Pin for controlling the backlight. By default not used.
ttodorov 24:ac6e35658037 87 * \param RD Pin for the RD signal. This line is not needed by the driver, so if you would like to
ttodorov 24:ac6e35658037 88 * use the pin on the mbed for something else, just pull-up the respective pin on the LCD high,
ttodorov 24:ac6e35658037 89 * and do not assign a value to this parameter when creating the controller instance.
ttodorov 24:ac6e35658037 90 * \param blType The backlight type, the default is to utilize the pin - if supplied - as a simple on/off switch
ttodorov 24:ac6e35658037 91 * \param defaultBacklightLevel If using PWM to control backlight, this would be the default brightness in percent after LCD initialization.
ttodorov 24:ac6e35658037 92 */
ttodorov 23:eca4414196ca 93 ILI9328_LCD( PinName CS, PinName RESET, PinName RS, PinName WR, BusOut* DATA_PORT, PinName BL = NC, PinName RD = NC, backlight_t blType = Constant, float defaultBackLightLevel = 1.0 );
ttodorov 24:ac6e35658037 94
ttodorov 24:ac6e35658037 95 /** Initialize display.
ttodorov 24:ac6e35658037 96 *
ttodorov 24:ac6e35658037 97 * Wakes up the display from sleep, initializes power parameters.
ttodorov 24:ac6e35658037 98 * This function must be called first, befor any painting on the
ttodorov 24:ac6e35658037 99 * display is done, otherwise the positioning of graphical elements
ttodorov 24:ac6e35658037 100 * will not work properly and any paynt operation will not be visible
ttodorov 24:ac6e35658037 101 * or produce garbage.
ttodorov 24:ac6e35658037 102 *
ttodorov 24:ac6e35658037 103 * \param oritentation The display orientation, landscape is default.
ttodorov 24:ac6e35658037 104 * \param colors The correct color depth to use for the pixel data. Value is disregarded.
ttodorov 24:ac6e35658037 105 */
ttodorov 23:eca4414196ca 106 virtual void Initialize( orientation_t orientation = LANDSCAPE, colordepth_t colors = RGB16 );
ttodorov 24:ac6e35658037 107
ttodorov 24:ac6e35658037 108 /** Puts the display to sleep.
ttodorov 24:ac6e35658037 109 *
ttodorov 24:ac6e35658037 110 * When the display is in sleep mode, its power consumption is
ttodorov 24:ac6e35658037 111 * minimized. Before new pixel data can be written to the display
ttodorov 24:ac6e35658037 112 * memory, the controller needs to be brought out of sleep mode.
ttodorov 24:ac6e35658037 113 * \sa #WakeUp( void );
ttodorov 24:ac6e35658037 114 * \remarks The result of this operation might not be exactly as
ttodorov 24:ac6e35658037 115 * expected. Putting the display to sleep will cause the
ttodorov 24:ac6e35658037 116 * controller to switch to the standard color of the LCD,
ttodorov 24:ac6e35658037 117 * so depending on whether the display is normally white,
ttodorov 24:ac6e35658037 118 * or normally dark, the screen might or might not go
ttodorov 24:ac6e35658037 119 * dark. Additional power saving can be achieved, if
ttodorov 24:ac6e35658037 120 * the backlight of the used display is not hardwired on
ttodorov 24:ac6e35658037 121 * the PCB and can be controlled via the BL pin.
ttodorov 24:ac6e35658037 122 */
ttodorov 23:eca4414196ca 123 virtual void Sleep( void );
ttodorov 24:ac6e35658037 124
ttodorov 24:ac6e35658037 125 /** Wakes up the display from sleep mode.
ttodorov 24:ac6e35658037 126 *
ttodorov 24:ac6e35658037 127 * This function needs to be called before any other, when the
ttodorov 24:ac6e35658037 128 * display has been put into sleep mode by a previois call to
ttodorov 24:ac6e35658037 129 * #Sleep( void ).
ttodorov 24:ac6e35658037 130 */
ttodorov 23:eca4414196ca 131 virtual void WakeUp( void );
ttodorov 23:eca4414196ca 132
ttodorov 23:eca4414196ca 133 protected:
ttodorov 24:ac6e35658037 134 /** Sends a command to the display.
ttodorov 24:ac6e35658037 135 *
ttodorov 24:ac6e35658037 136 * \param cmd The display command.
ttodorov 24:ac6e35658037 137 * \remarks Commands are controller-specific and this function needs to
ttodorov 24:ac6e35658037 138 * be implemented separately for each available controller.
ttodorov 24:ac6e35658037 139 */
ttodorov 23:eca4414196ca 140 virtual void WriteCmd( unsigned short cmd );
ttodorov 24:ac6e35658037 141
ttodorov 24:ac6e35658037 142 /** Sends pixel data to the display.
ttodorov 24:ac6e35658037 143 *
ttodorov 24:ac6e35658037 144 * \param data The display data.
ttodorov 24:ac6e35658037 145 * \remarks Sending data is controller-specific and this function needs to
ttodorov 24:ac6e35658037 146 * be implemented separately for each available controller.
ttodorov 24:ac6e35658037 147 */
ttodorov 23:eca4414196ca 148 virtual void WriteData( unsigned short data );
ttodorov 24:ac6e35658037 149
ttodorov 24:ac6e35658037 150 /** Assigns a chunk of the display memory to receive data.
ttodorov 24:ac6e35658037 151 *
ttodorov 24:ac6e35658037 152 * When data is sent to the display after this function completes, the opertion will
ttodorov 24:ac6e35658037 153 * start from the begining of the assigned address (pixel position) and the pointer
ttodorov 24:ac6e35658037 154 * will be automatically incremented so that the next data write operation will continue
ttodorov 24:ac6e35658037 155 * with the next pixel from the memory block. If more data is written than available
ttodorov 24:ac6e35658037 156 * pixels, at the end of the block the pointer will jump back to its beginning and
ttodorov 24:ac6e35658037 157 * commence again, until the next address change command is sent to the display.
ttodorov 24:ac6e35658037 158 *
ttodorov 24:ac6e35658037 159 * \param x1 The X coordinate of the pixel at the beginning of the block.
ttodorov 24:ac6e35658037 160 * \param y1 The Y coordinate of the pixel at the beginning of the block.
ttodorov 24:ac6e35658037 161 * \param x2 The X coordinate of the pixel at the end of the block.
ttodorov 24:ac6e35658037 162 * \param y2 The Y coordinate of the pixel at the end of the block.
ttodorov 24:ac6e35658037 163 * \remarks Addressing commands are controller-specific and this function needs to be
ttodorov 24:ac6e35658037 164 * implemented separately for each available controller.
ttodorov 24:ac6e35658037 165 */
ttodorov 23:eca4414196ca 166 virtual void SetXY( unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2 );
ttodorov 24:ac6e35658037 167
ttodorov 24:ac6e35658037 168 /** Sets the color of the pixel at the address pointer of the controller.
ttodorov 24:ac6e35658037 169 *
ttodorov 24:ac6e35658037 170 * This function is to be provided by each implementation separately in
ttodorov 24:ac6e35658037 171 * order to account for different color depth used by the controller.
ttodorov 24:ac6e35658037 172 * \param color The color of the pixel.
ttodorov 24:ac6e35658037 173 * \param mode The depth (palette) of the color.
ttodorov 24:ac6e35658037 174 */
ttodorov 23:eca4414196ca 175 virtual void SetPixelColor( unsigned int color, colordepth_t mode = RGB24 );
ttodorov 23:eca4414196ca 176
ttodorov 23:eca4414196ca 177 private:
ttodorov 23:eca4414196ca 178 DigitalOut _lcd_pin_wr;
ttodorov 23:eca4414196ca 179 BusOut* _lcd_port;
ttodorov 23:eca4414196ca 180 DigitalOut* _lcd_pin_bl;
ttodorov 23:eca4414196ca 181 DigitalOut* _lcd_pin_rd;
ttodorov 23:eca4414196ca 182 };
ttodorov 23:eca4414196ca 183
ttodorov 23:eca4414196ca 184 #ifdef __cplusplus
ttodorov 23:eca4414196ca 185 }
ttodorov 23:eca4414196ca 186 #endif
ttodorov 23:eca4414196ca 187
ttodorov 23:eca4414196ca 188 #endif /* TFTLCD_ILI9328_H */