Lib for the new LCD Display with ILI9341 controller

Dependents:   TFT_Test_ILI9341 touch_piirto TFT_banggood TFT_Test_ILI9341-a-fish ... more

Lib for 320*240 Pixel Color LCD with ILI9341 controller. Based on MI0283QT-9 datasheet. The lib is based on the http://mbed.org/cookbook/SPI-driven-QVGA-TFT code for the older LCD board.

The lib is using the 4 line serial data interface. The IM pins have to be set to 1110 (IM3-IM0) to use this mode. It use the SPI hardware.

I have started to speed up the lib with using DMA and direct SPI programming. To do this I have to split the code for the different platforms. To prevent unreadable code with a lot of #ifdef... I have create a new file. The #ifdef definition around is switching between the platforms. I will add the other Nucleo platforms. If you want to support others - see ..._NUCLEO.cpp , port and send me the code to add.

Display 1

If you use the TFT Proto from MikroElektronika http://www.mikroe.com/eng/products/view/474/tft-proto-board/ you have to connect : /media/uploads/dreschpe/tft_proto.png

MBEDDisplay
+ 3,3V3,3V
GNDGND
mosiSDI
misoSDO
sckRS
csCS
resetRST
dcWR/SCL
GNDIM0
+3,3VIM1 IM2 IM3
GNDDB0 - DB17
GNDRD

The backlite LED need a resistor to limit the current. You can use two 10R resistors parallel to get 5R driven by 3.3V.

Display 2

Watterott is also selling a ILI9341 based QVGA TFT : http://www.watterott.com/de/MI0283QT-2-Adapter

Unfortunately this adapter is set to 9 bit SPI mode via the mode pins IM0-IM3. If you want to patch this - like I have done - you have to desolder the TFT from the pcb to cut some traces. This is a flexible print. Only for people with soldering skills ! You also have to get access to pin 36 for the dc signal. Cut the GND connection. You can use the level converter used for the LCD_LED signal. Mosfet Q1 can be driven with a logic signal without converter. Watterott will change this in a future revision.

/media/uploads/dreschpe/mi0283qt_v12_patch.pdf

Display 3

There are inexpensive displays from china. You can get them at: http://www.banggood.com/2_2-Inch-Serial-TFT-SPI-LCD-Screen-Module-HD-240-X-320-5110-Compatible-p-912854.html The board has also a SD card connector at the backside, but no touch.

/media/uploads/dreschpe/tft3_1.jpg /media/uploads/dreschpe/tft3_2.jpg

The board can be used without modification. Connect VCC with 5V USB out. There is a voltage regulator on board. To use the SD card simply import the SDFileSystem and connect it to the second SPI.

Fonts

How to get nice looking fonts ?

To print characters to a graphic screen we need a font. To code a font by paper is ok for a small lcd, but for a 320*240 pixel display we need bigger fonts. A 12*12 pixel font is readable, but a lot of work to construct.

Fonts can be made with the GLCD Font Creator also from http://www.mikroe.com .

With this program you can load a window font and convert it into a c-array. To use this Font with my lib you have to add 4 parameter at the beginning of the font array. - the number of byte / char - the vertial size in pixel - the horizontal size in pixel - the number of byte per vertical line (it is vertical size / 8 ) You also have to change the array to char[]. After that you can switch between different fonts with set_font(unsigned char* font); The horizontal size of each character is also stored in the font. It look better if you use bigger fonts or italic. The letter M is wider than a l.

Here are some Fonts from me : http://mbed.org/users/dreschpe/code/TFT_fonts/

The small made for the mbed lab board : http://mbed.org/users/dreschpe/code/LCD_fonts/

And from Peter Holzleitner : http://mbed.org/users/pholzleitner/code/SourceCodePro31-SB/

Text commands :

You can use the claim() function to redirect the output to stdout or stderr to the TFT. After claim(stdout) you can simply use the printf function to print to the TFT.

  • locate(x,y); function is used to setup the cursor position. x,y are the pixel position. This was changed from row,column in older lib !

There are two parameter to setup the color of the text :

  • background(color);
  • foreground(color); All color are 16bit: R5 G6 B5.
  • set_orientation(); This command select one of the 4 directions to use the display. This command is also working on the graphical commands.

Graphics

Graphic commands :

  • cls(); Fill the screen with background color
  • pixel(x,y,color); set a single pixel at x,y with color
  • line(x0,y0,x1,y1,color); draw a line from x0,y0 to x1,y1 with color
  • rect(x0,y0,x1,y1,color); draw a rectangle x0,y0 to x1,y1 with color
  • fillrect(x0,y0,x1,y1,color); draw a filled rectangle
  • circle( x0,y0,radius ,color); draw a circle around x0,y0 with radius
  • fillcircle(x0,y0,radius ,color); draw a filled circle around x0,y0 with radius
  • Bitmap(x0,y0,w,h,*bitmap); paint a bitmap with width w and high h starting at x0,y0 (upper left corner)
  • BMP_16(x0,y0,*bmp); paint a bmp file out of the internal drive or a SD-card

How to transfer a grafic to the mbed ?

The hard way - but fast to load :

Load from mbed flash. It consume a lot of flash memory. To construct a bitmap array we can use gimp. http://www.gimp.org/ Load a image (edit and resize) and export it as BMP. You have to select the option 16 bit R5 G6 B5 !

To convert this file into a c-array you can use the hex-editor winhex. (http://www.x-ways.net/winhex/index-m.html) The eval version can handle the small files. We don`t need the bmp header. Mark the data starting at offset 0x46 to the end of file. Use "edit -> copy block -> C Source" to export this data as C array. Paste the data into a C file into the mbed compiler. The editor will generate a array of char[]. To use 16 bit DMA on this we have to put a __align(2) in front of the definition. To put it into Flash we change it to static const unsigned char bmp[]{...}

__align(2)
static const unsigned char bmp[]{
      0xCB, 0x5A, 0x5C, 0xE7,....

};

The easy way - but slower to load:

With the BMP_16 command we can load a picture out of the internal drive or a SD-card to the display.

  • BMP_16(x0,y0,"/local/test.bmp"); paint test.bmp out of the internal drive to x0, y0
  • BMP_16(x0,y0,"/sd/test.bmp"); paint test.bmp out of a external SD-card to x0, y0

simply copy test.bmp to the mbed usb drive or the SD-card. The bmp has to be saved with the options 16 bit R5 G6 B5 ! You can use the program gimp to convert pictures into the 16 bit bmp format.

sample code

http://mbed.org/users/dreschpe/code/TFT_Test_ILI9341/

// example to test the TFT Display
// Thanks to the GraphicsDisplay and TextDisplay classes
// test2.bmp has to be on the mbed file system

#include "stdio.h"
#include "mbed.h"
#include "SPI_TFT_ILI9341.h"
#include "string"
#include "Arial12x12.h"
#include "Arial24x23.h"
#include "Arial28x28.h"
#include "font_big.h"

extern unsigned char p1[];  // the mbed logo

DigitalOut LCD_LED(p21); // the Watterott display has a backlight switch
DigitalOut CS_Touch(p15); // disable the touch controller on the Watterott display

// the TFT is connected to SPI pin 5-7
SPI_TFT_ILI9341 TFT(p5, p6, p7, p8, p9, p10,"TFT"); // mosi, miso, sclk, cs, reset, dc

int main()
{
    int i;
    LCD_LED = 1;  // backlight on
    CS_Touch = 1; 
   
    TFT.claim(stdout);      // send stdout to the TFT display
    //TFT.claim(stderr);      // send stderr to the TFT display
    TFT.set_orientation(1);
    TFT.background(Black);    // set background to black
    TFT.foreground(White);    // set chars to white
    TFT.cls();                // clear the screen

    //first show the 4 directions
    TFT.set_orientation(0);
    TFT.background(Black);
    TFT.cls();

    TFT.set_font((unsigned char*) Arial12x12);
    TFT.locate(0,0);
    printf("  Hello Mbed 0");

    TFT.set_orientation(1);
    TFT.locate(0,0);
    printf("  Hello Mbed 1");
    TFT.set_orientation(2);
    TFT.locate(0,0);
    printf("  Hello Mbed 2");
    TFT.set_orientation(3);
    TFT.locate(0,0);
    printf("  Hello Mbed 3");
    TFT.set_orientation(1);
    TFT.set_font((unsigned char*) Arial24x23);
    TFT.locate(50,100);
    TFT.printf("TFT orientation");

/media/uploads/dreschpe/orient.jpg

// draw some graphics
    TFT.cls();
    TFT.set_font((unsigned char*) Arial24x23);
    TFT.locate(100,100);
    TFT.printf("Graphic");

    TFT.line(0,0,100,0,Green);
    TFT.line(0,0,0,200,Green);
    TFT.line(0,0,100,200,Green);

    TFT.rect(100,50,150,100,Red);
    TFT.fillrect(180,25,220,70,Blue);

    TFT.circle(80,150,33,White);
    TFT.fillcircle(160,190,20,Yellow);

    double s;

    for (i=0; i<320; i++) {
        s =20 * sin((long double) i / 10 );
        TFT.pixel(i,100 + (int)s ,Red);
    }

/media/uploads/dreschpe/grafik.jpg

   // bigger text
    TFT.foreground(White);
    TFT.background(Blue);
    TFT.cls();
    TFT.set_font((unsigned char*) Arial24x23);
    TFT.locate(0,0);
    TFT.printf("Different Fonts :");

    TFT.set_font((unsigned char*) Neu42x35);
    TFT.locate(0,30);
    TFT.printf("Hello Mbed 1");
    TFT.set_font((unsigned char*) Arial24x23);
    TFT.locate(20,80);
    TFT.printf("Hello Mbed 2");
    TFT.set_font((unsigned char*) Arial12x12);
    TFT.locate(35,120);
    TFT.printf("Hello Mbed 3");

/media/uploads/dreschpe/fonts2.jpg

    // mbed logo from flash
    // defined in graphics.c
    //__align(4)
    //unsigned char p1[18920] = {
    //0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, ....
    // 
    TFT.background(Black);
    TFT.cls();

    TFT.locate(10,10);
    TFT.printf("Graphic from Flash");

    TFT.Bitmap(90,90,172,55,p1);

/media/uploads/dreschpe/mbed.jpg

  
  #include "SDFileSystem.h"
  // connect a sd-card to the second spi or use the local filesystem of the LPC   
  SDFileSystem sd(p11, p12, p13, p14, "sd"); // mosi,miso,sck,cs
  TFT.cls();
  TFT.locate(10,110);
  TFT.printf("Graphic from external SD-card");
  int err = TFT.BMP_16(1,140,"/sd/test.bmp");  // load test.bmp from external SD-card
  TFT.locate(10,120);
  if (err != 1) TFT.printf(" - Err: %d",err);

/media/uploads/dreschpe/bmp16.jpg

SPI_TFT_ILI9341.cpp

Committer:
dreschpe
Date:
2014-06-25
Revision:
13:b2b3e5430f81
Parent:
12:98cc5c193ecd

File content as of revision 13:b2b3e5430f81:

/* mbed library for 240*320 pixel display TFT based on ILI9341 LCD Controller
 * Copyright (c) 2013 Peter Drescher - DC2PD
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
 
// 12.06.13 fork from SPI_TFT code because controller is different ...
// 14.07.13 Test with real display and bugfix 
// 18.10.13 Better Circle function from Michael Ammann
// 22.10.13 Fixes for Kinetis Board - 8 bit spi
// 26.01.14 Change interface for BMP_16 to also use SD-cards
// 23.06.14 switch back to old Version - fork for L152 
// 24.06.14 Add compiler flag for optimized L152 version
// 25.06.14 Add optimized F103 version

// exclude this file for platforms with optimized version
#if defined TARGET_NUCLEO_L152RE || defined TARGET_NUCLEO_F103RB || defined TARGET_LPC1768
// this platforms are supported by special version in different source file
#else

#include "SPI_TFT_ILI9341.h"
#include "mbed.h"

#define BPP         16                  // Bits per pixel    
         
//extern Serial pc;
//extern DigitalOut xx;     // debug !!

SPI_TFT_ILI9341::SPI_TFT_ILI9341(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName reset, PinName dc, const char *name)
    : GraphicsDisplay(name), SPI(mosi, miso, sclk,NC), _cs(cs), _reset(reset), _dc(dc)
{
    
    orientation = 0;
    char_x = 0;
    SPI::format(8,3);                  // 8 bit spi mode 3
    SPI::frequency(10000000);          // 10 Mhz SPI clock
    tft_reset();
}

int SPI_TFT_ILI9341::width()
{
    if (orientation == 0 || orientation == 2) return 240;
    else return 320;
}


int SPI_TFT_ILI9341::height()
{
    if (orientation == 0 || orientation == 2) return 320;
    else return 240;
}


void SPI_TFT_ILI9341::set_orientation(unsigned int o)
{
    orientation = o;
    wr_cmd(0x36);                     // MEMORY_ACCESS_CONTROL
    switch (orientation) {
        case 0:
            SPI::write(0x48);
            break;
        case 1:
            SPI::write(0x28);
            break;
        case 2:
            SPI::write(0x88);
            break;
        case 3:
            SPI::write(0xE8);
            break;
    }
    _cs = 1; 
    WindowMax();
} 


// write command to tft register

void SPI_TFT_ILI9341::wr_cmd(unsigned char cmd)
{
    _dc = 0;
    _cs = 0;
    SPI::write(cmd);      // mbed lib
    _dc = 1;
}



void SPI_TFT_ILI9341::wr_dat(unsigned char dat)
{
   SPI::write(dat);      // mbed lib
}



// the ILI9341 can read 

char SPI_TFT_ILI9341::rd_byte(unsigned char cmd)
{
    char r;
    _dc = 0;
    _cs = 0;
    SPI::write(cmd);      // mbed lib
    _cs = 1;
    r = SPI::write(0xff);
    _cs = 1;    
    return(r);
}

// read 32 bit
int SPI_TFT_ILI9341::rd_32(unsigned char cmd)
{
    int d;
    char r;
    _dc = 0;
    _cs = 0;
    d = cmd;
    d = d << 1;
    SPI::format(9,3);    // we have to add a dummy clock cycle
    SPI::write(d);
    SPI::format(8,3);   
    _dc = 1;
    r = SPI::write(0xff);
    d = r;
    r = SPI::write(0xff);
    d = (d << 8) | r;
    r = SPI::write(0xff);
    d = (d << 8) | r;
    r = SPI::write(0xff);
    d = (d << 8) | r;
    _cs = 1;    
    return(d);
}

int  SPI_TFT_ILI9341::Read_ID(void){
    int r;
    r = rd_byte(0x0A);
    r = rd_byte(0x0A);
    r = rd_byte(0x0A);
    r = rd_byte(0x0A);
    return(r);
}


// Init code based on MI0283QT datasheet

void SPI_TFT_ILI9341::tft_reset()
{
    _cs = 1;                           // cs high
    _dc = 1;                           // dc high 
    _reset = 0;                        // display reset

    wait_us(50);
    _reset = 1;                       // end hardware reset
    wait_ms(5);
     
    wr_cmd(0x01);                     // SW reset  
    wait_ms(5);
    wr_cmd(0x28);                     // display off  

    /* Start Initial Sequence ----------------------------------------------------*/
     wr_cmd(0xCF);                     
     SPI::write(0x00);
     SPI::write(0x83);
     SPI::write(0x30);
     _cs = 1;
     
     wr_cmd(0xED);                     
     SPI::write(0x64);
     SPI::write(0x03);
     SPI::write(0x12);
     SPI::write(0x81);
     _cs = 1;
     
     wr_cmd(0xE8);                     
     SPI::write(0x85);
     SPI::write(0x01);
     SPI::write(0x79);
     _cs = 1;
     
     wr_cmd(0xCB);                     
     SPI::write(0x39);
     SPI::write(0x2C);
     SPI::write(0x00);
     SPI::write(0x34);
     SPI::write(0x02);
     _cs = 1;
           
     wr_cmd(0xF7);                     
     SPI::write(0x20);
     _cs = 1;
           
     wr_cmd(0xEA);                     
     SPI::write(0x00);
     SPI::write(0x00);
     _cs = 1;
     
     wr_cmd(0xC0);                     // POWER_CONTROL_1
     SPI::write(0x26);
     _cs = 1;
 
     wr_cmd(0xC1);                     // POWER_CONTROL_2
     SPI::write(0x11);
     _cs = 1;
     
     wr_cmd(0xC5);                     // VCOM_CONTROL_1
     SPI::write(0x35);
     SPI::write(0x3E);
     _cs = 1;
     
     wr_cmd(0xC7);                     // VCOM_CONTROL_2
     SPI::write(0xBE);
     _cs = 1; 
     
     wr_cmd(0x36);                     // MEMORY_ACCESS_CONTROL
     SPI::write(0x48);
     _cs = 1; 
     
     wr_cmd(0x3A);                     // COLMOD_PIXEL_FORMAT_SET
     SPI::write(0x55);                 // 16 bit pixel 
     _cs = 1;
     
     wr_cmd(0xB1);                     // Frame Rate
     SPI::write(0x00);
     SPI::write(0x1B);               
     _cs = 1;
     
     wr_cmd(0xF2);                     // Gamma Function Disable
     SPI::write(0x08);
     _cs = 1; 
     
     wr_cmd(0x26);                     
     SPI::write(0x01);                 // gamma set for curve 01/2/04/08
     _cs = 1; 
     
     wr_cmd(0xE0);                     // positive gamma correction
     SPI::write(0x1F); 
     SPI::write(0x1A); 
     SPI::write(0x18); 
     SPI::write(0x0A); 
     SPI::write(0x0F); 
     SPI::write(0x06); 
     SPI::write(0x45); 
     SPI::write(0x87); 
     SPI::write(0x32); 
     SPI::write(0x0A); 
     SPI::write(0x07); 
     SPI::write(0x02); 
     SPI::write(0x07);
     SPI::write(0x05); 
     SPI::write(0x00);
     _cs = 1;
     
     wr_cmd(0xE1);                     // negativ gamma correction
     SPI::write(0x00); 
     SPI::write(0x25); 
     SPI::write(0x27); 
     SPI::write(0x05); 
     SPI::write(0x10); 
     SPI::write(0x09); 
     SPI::write(0x3A); 
     SPI::write(0x78); 
     SPI::write(0x4D); 
     SPI::write(0x05); 
     SPI::write(0x18); 
     SPI::write(0x0D); 
     SPI::write(0x38);
     SPI::write(0x3A); 
     SPI::write(0x1F);
     _cs = 1;
     
     WindowMax ();
     
     //wr_cmd(0x34);                     // tearing effect off
     //_cs = 1;
     
     //wr_cmd(0x35);                     // tearing effect on
     //_cs = 1;
      
     wr_cmd(0xB7);                       // entry mode
     SPI::write(0x07);
     _cs = 1;
     
     wr_cmd(0xB6);                       // display function control
     SPI::write(0x0A);
     SPI::write(0x82);
     SPI::write(0x27);
     SPI::write(0x00);
     _cs = 1;
     
     wr_cmd(0x11);                     // sleep out
     _cs = 1;
     
     wait_ms(100);
     
     wr_cmd(0x29);                     // display on
     _cs = 1;
     
     wait_ms(100);
     
 }


void SPI_TFT_ILI9341::pixel(int x, int y, int color)
{
    wr_cmd(0x2A);
    SPI::write(x >> 8);
    SPI::write(x);
    _cs = 1;
    wr_cmd(0x2B);
    SPI::write(y >> 8);
    SPI::write(y);
    _cs = 1;
    wr_cmd(0x2C);  // send pixel
    #if defined TARGET_KL25Z  // 8 Bit SPI
    SPI::write(color >> 8);
    SPI::write(color & 0xff);
    #else 
    SPI::format(16,3);                            // switch to 16 bit Mode 3
    SPI::write(color);                              // Write D0..D15
    SPI::format(8,3);
    #endif
    _cs = 1;
}


void SPI_TFT_ILI9341::window (unsigned int x, unsigned int y, unsigned int w, unsigned int h)
{
    wr_cmd(0x2A);
    SPI::write(x >> 8);
    SPI::write(x);
    SPI::write((x+w-1) >> 8);
    SPI::write(x+w-1);
    
    _cs = 1;
    wr_cmd(0x2B);
    SPI::write(y >> 8);
    SPI::write(y);
    SPI::write((y+h-1) >> 8);
    SPI::write(y+h-1);
    _cs = 1;
}


void SPI_TFT_ILI9341::WindowMax (void)
{
    window (0, 0, width(),  height());
}



void SPI_TFT_ILI9341::cls (void)
{
   // we can use the fillrect function 
   fillrect(0,0,width()-1,height()-1,_background);
}


void SPI_TFT_ILI9341::circle(int x0, int y0, int r, int color)
{

    int x = -r, y = 0, err = 2-2*r, e2;
    do {
        pixel(x0-x, y0+y,color);
        pixel(x0+x, y0+y,color);
        pixel(x0+x, y0-y,color);
        pixel(x0-x, y0-y,color);
        e2 = err;
        if (e2 <= y) {
            err += ++y*2+1;
            if (-x == y && e2 <= x) e2 = 0;
        }
        if (e2 > x) err += ++x*2+1;
    } while (x <= 0);

}

void SPI_TFT_ILI9341::fillcircle(int x0, int y0, int r, int color)
{
    int x = -r, y = 0, err = 2-2*r, e2;
    do {
        vline(x0-x, y0-y, y0+y, color);
        vline(x0+x, y0-y, y0+y, color);
        e2 = err;
        if (e2 <= y) {
            err += ++y*2+1;
            if (-x == y && e2 <= x) e2 = 0;
        }
        if (e2 > x) err += ++x*2+1;
    } while (x <= 0);
}


void SPI_TFT_ILI9341::hline(int x0, int x1, int y, int color)
{
    int w;
    w = x1 - x0 + 1;
    window(x0,y,w,1);
    wr_cmd(0x2C);  // send pixel
    #if defined TARGET_KL25Z  // 8 Bit SPI
    int j;
    for (j=0; j<w; j++) {
        SPI::write(color >> 8);
        SPI::write(color & 0xff);
    } 
    #else 
    SPI::format(16,3);                            // switch to 16 bit Mode 3
    int j;
    for (j=0; j<w; j++) {
        SPI::write(color);
    }
    SPI::format(8,3);
    #endif
    _cs = 1;
    WindowMax();
    return;
}

void SPI_TFT_ILI9341::vline(int x, int y0, int y1, int color)
{
    int h;
    h = y1 - y0 + 1;
    window(x,y0,1,h);
    wr_cmd(0x2C);  // send pixel
    #if defined TARGET_KL25Z  // 8 Bit SPI
    for (int y=0; y<h; y++) {
        SPI::write(color >> 8);
        SPI::write(color & 0xff);
    } 
    #else 
    SPI::format(16,3);                            // switch to 16 bit Mode 3
    for (int y=0; y<h; y++) {
        SPI::write(color);
    }
    SPI::format(8,3);
    #endif
    _cs = 1;
    WindowMax();
    return;
}



void SPI_TFT_ILI9341::line(int x0, int y0, int x1, int y1, int color)
{
    //WindowMax();
    int   dx = 0, dy = 0;
    int   dx_sym = 0, dy_sym = 0;
    int   dx_x2 = 0, dy_x2 = 0;
    int   di = 0;

    dx = x1-x0;
    dy = y1-y0;

    if (dx == 0) {        /* vertical line */
        if (y1 > y0) vline(x0,y0,y1,color);
        else vline(x0,y1,y0,color);
        return;
    }

    if (dx > 0) {
        dx_sym = 1;
    } else {
        dx_sym = -1;
    }
    if (dy == 0) {        /* horizontal line */
        if (x1 > x0) hline(x0,x1,y0,color);
        else  hline(x1,x0,y0,color);
        return;
    }

    if (dy > 0) {
        dy_sym = 1;
    } else {
        dy_sym = -1;
    }

    dx = dx_sym*dx;
    dy = dy_sym*dy;

    dx_x2 = dx*2;
    dy_x2 = dy*2;

    if (dx >= dy) {
        di = dy_x2 - dx;
        while (x0 != x1) {

            pixel(x0, y0, color);
            x0 += dx_sym;
            if (di<0) {
                di += dy_x2;
            } else {
                di += dy_x2 - dx_x2;
                y0 += dy_sym;
            }
        }
        pixel(x0, y0, color);
    } else {
        di = dx_x2 - dy;
        while (y0 != y1) {
            pixel(x0, y0, color);
            y0 += dy_sym;
            if (di < 0) {
                di += dx_x2;
            } else {
                di += dx_x2 - dy_x2;
                x0 += dx_sym;
            }
        }
        pixel(x0, y0, color);
    }
    return;
}


void SPI_TFT_ILI9341::rect(int x0, int y0, int x1, int y1, int color)
{

    if (x1 > x0) hline(x0,x1,y0,color);
    else  hline(x1,x0,y0,color);

    if (y1 > y0) vline(x0,y0,y1,color);
    else vline(x0,y1,y0,color);

    if (x1 > x0) hline(x0,x1,y1,color);
    else  hline(x1,x0,y1,color);

    if (y1 > y0) vline(x1,y0,y1,color);
    else vline(x1,y1,y0,color);

    return;
}



void SPI_TFT_ILI9341::fillrect(int x0, int y0, int x1, int y1, int color)
{

    int h = y1 - y0 + 1;
    int w = x1 - x0 + 1;
    int pixel = h * w;
    window(x0,y0,w,h);
    wr_cmd(0x2C);  // send pixel 
    #if defined TARGET_KL25Z  // 8 Bit SPI
    for (int p=0; p<pixel; p++) {
        SPI::write(color >> 8);
        SPI::write(color & 0xff);
    }
   #else
    SPI::format(16,3);                            // switch to 16 bit Mode 3
    for (int p=0; p<pixel; p++) {
        SPI::write(color);
    }
    SPI::format(8,3);
    #endif
    _cs = 1;
    WindowMax();
    return;
}


void SPI_TFT_ILI9341::locate(int x, int y)
{
    char_x = x;
    char_y = y;
}



int SPI_TFT_ILI9341::columns()
{
    return width() / font[1];
}



int SPI_TFT_ILI9341::rows()
{
    return height() / font[2];
}



int SPI_TFT_ILI9341::_putc(int value)
{
    if (value == '\n') {    // new line
        char_x = 0;
        char_y = char_y + font[2];
        if (char_y >= height() - font[2]) {
            char_y = 0;
        }
    } else {
        character(char_x, char_y, value);
    }
    return value;
}


void SPI_TFT_ILI9341::character(int x, int y, int c)
{
    unsigned int hor,vert,offset,bpl,j,i,b;
    unsigned char* zeichen;
    unsigned char z,w;

    if ((c < 31) || (c > 127)) return;   // test char range

    // read font parameter from start of array
    offset = font[0];                    // bytes / char
    hor = font[1];                       // get hor size of font
    vert = font[2];                      // get vert size of font
    bpl = font[3];                       // bytes per line

    if (char_x + hor > width()) {
        char_x = 0;
        char_y = char_y + vert;
        if (char_y >= height() - font[2]) {
            char_y = 0;
        }
    }
    window(char_x, char_y,hor,vert); // char box
    wr_cmd(0x2C);  // send pixel
    #ifndef TARGET_KL25Z  // 16 Bit SPI 
    SPI::format(16,3);   
    #endif                         // switch to 16 bit Mode 3
    zeichen = &font[((c -32) * offset) + 4]; // start of char bitmap
    w = zeichen[0];                          // width of actual char
     for (j=0; j<vert; j++) {  //  vert line
        for (i=0; i<hor; i++) {   //  horz line
            z =  zeichen[bpl * i + ((j & 0xF8) >> 3)+1];
            b = 1 << (j & 0x07);
            if (( z & b ) == 0x00) {
               #ifndef TARGET_KL25Z  // 16 Bit SPI 
                SPI::write(_background);
               #else
                SPI::write(_background >> 8);
                SPI::write(_background & 0xff);
                #endif
            } else {
                #ifndef TARGET_KL25Z  // 16 Bit SPI
                SPI::write(_foreground);
                #else
                SPI::write(_foreground >> 8);
                SPI::write(_foreground & 0xff);
                #endif
            }
        }
    }
    _cs = 1;
    #ifndef TARGET_KL25Z  // 16 Bit SPI
    SPI::format(8,3);
    #endif
    WindowMax();
    if ((w + 2) < hor) {                   // x offset to next char
        char_x += w + 2;
    } else char_x += hor;
}


void SPI_TFT_ILI9341::set_font(unsigned char* f)
{
    font = f;
}



void SPI_TFT_ILI9341::Bitmap(unsigned int x, unsigned int y, unsigned int w, unsigned int h,unsigned char *bitmap)
{
    unsigned int  j;
    int padd;
    unsigned short *bitmap_ptr = (unsigned short *)bitmap;
    #if defined TARGET_KL25Z  // 8 Bit SPI
        unsigned short pix_temp;
    #endif
    
    unsigned int i;
    
    // the lines are padded to multiple of 4 bytes in a bitmap
    padd = -1;
    do {
        padd ++;
    } while (2*(w + padd)%4 != 0);
    window(x, y, w, h);
    bitmap_ptr += ((h - 1)* (w + padd));
    wr_cmd(0x2C);  // send pixel
    #ifndef TARGET_KL25Z  // 16 Bit SPI 
    SPI::format(16,3);
    #endif                            // switch to 16 bit Mode 3
    for (j = 0; j < h; j++) {         //Lines
        for (i = 0; i < w; i++) {     // one line
            #if defined TARGET_KL25Z  // 8 Bit SPI
                pix_temp = *bitmap_ptr;
                SPI::write(pix_temp >> 8);
                SPI::write(pix_temp);
                bitmap_ptr++;
            #else
                SPI::write(*bitmap_ptr);    // one line
                bitmap_ptr++;
            #endif
        }
        bitmap_ptr -= 2*w;
        bitmap_ptr -= padd;
    }
    _cs = 1;
    #ifndef TARGET_KL25Z  // 16 Bit SPI 
    SPI::format(8,3);
    #endif
    WindowMax();
}


// local filesystem is not implemented in kinetis board , but you can add a SD card

int SPI_TFT_ILI9341::BMP_16(unsigned int x, unsigned int y, const char *Name_BMP)
{

#define OffsetPixelWidth    18
#define OffsetPixelHeigh    22
#define OffsetFileSize      34
#define OffsetPixData       10
#define OffsetBPP           28

    char filename[50];
    unsigned char BMP_Header[54];
    unsigned short BPP_t;
    unsigned int PixelWidth,PixelHeigh,start_data;
    unsigned int    i,off;
    int padd,j;
    unsigned short *line;

    // get the filename
    i=0;
    while (*Name_BMP!='\0') {
        filename[i++]=*Name_BMP++;
    }
    filename[i] = 0;  
    
    FILE *Image = fopen((const char *)&filename[0], "rb");  // open the bmp file
    if (!Image) {
        return(0);      // error file not found !
    }

    fread(&BMP_Header[0],1,54,Image);      // get the BMP Header

    if (BMP_Header[0] != 0x42 || BMP_Header[1] != 0x4D) {  // check magic byte
        fclose(Image);
        return(-1);     // error no BMP file
    }

    BPP_t = BMP_Header[OffsetBPP] + (BMP_Header[OffsetBPP + 1] << 8);
    if (BPP_t != 0x0010) {
        fclose(Image);
        return(-2);     // error no 16 bit BMP
    }

    PixelHeigh = BMP_Header[OffsetPixelHeigh] + (BMP_Header[OffsetPixelHeigh + 1] << 8) + (BMP_Header[OffsetPixelHeigh + 2] << 16) + (BMP_Header[OffsetPixelHeigh + 3] << 24);
    PixelWidth = BMP_Header[OffsetPixelWidth] + (BMP_Header[OffsetPixelWidth + 1] << 8) + (BMP_Header[OffsetPixelWidth + 2] << 16) + (BMP_Header[OffsetPixelWidth + 3] << 24);
    if (PixelHeigh > height() + y || PixelWidth > width() + x) {
        fclose(Image);
        return(-3);      // to big
    }

    start_data = BMP_Header[OffsetPixData] + (BMP_Header[OffsetPixData + 1] << 8) + (BMP_Header[OffsetPixData + 2] << 16) + (BMP_Header[OffsetPixData + 3] << 24);

    line = (unsigned short *) malloc (2 * PixelWidth); // we need a buffer for a line
    if (line == NULL) {
        return(-4);         // error no memory
    }

    // the bmp lines are padded to multiple of 4 bytes
    padd = -1;
    do {
        padd ++;
    } while ((PixelWidth * 2 + padd)%4 != 0);

    window(x, y,PixelWidth ,PixelHeigh);
    wr_cmd(0x2C);  // send pixel
    #ifndef TARGET_KL25Z // only 8 Bit SPI 
    SPI::format(16,3);  
    #endif                          // switch to 16 bit Mode 3
    for (j = PixelHeigh - 1; j >= 0; j--) {               //Lines bottom up
        off = j * (PixelWidth  * 2 + padd) + start_data;   // start of line
        fseek(Image, off ,SEEK_SET);
        fread(line,1,PixelWidth * 2,Image);       // read a line - slow 
        for (i = 0; i < PixelWidth; i++) {        // copy pixel data to TFT
        #ifndef TARGET_KL25Z // only 8 Bit SPI
            SPI::write(line[i]);                  // one 16 bit pixel
        #else  
            SPI::write(line[i] >> 8);
            SPI::write(line[i]);
        #endif    
        } 
     }
    _cs = 1;
    SPI::format(8,3);
    free (line);
    fclose(Image);
    WindowMax();
    return(1);
}

#endif