N5110.cpp

00001 #include "mbed.h"
00002 #include "N5110.h"
00003  
00004 // overloaded constructor includes power pin - LCD Vcc connected to GPIO pin
00005 // this constructor works fine with LPC1768 - enough current sourced from GPIO
00006 // to power LCD. Doesn't work well with K64F.
00007 N5110::N5110(PinName const pwrPin,
00008              PinName const scePin,
00009              PinName const rstPin,
00010              PinName const dcPin,
00011              PinName const mosiPin,
00012              PinName const sclkPin,
00013              PinName const ledPin)
00014     :
00015     _spi(new SPI(mosiPin,NC,sclkPin)), // create new SPI instance and initialise
00016     _led(new PwmOut(ledPin)),
00017     _pwr(new DigitalOut(pwrPin)),
00018     _sce(new DigitalOut(scePin)),
00019     _rst(new DigitalOut(rstPin)),
00020     _dc(new DigitalOut(dcPin))
00021 {}
00022  
00023 // overloaded constructor does not include power pin - LCD Vcc must be tied to +3V3
00024 // Best to use this with K64F as the GPIO hasn't sufficient output current to reliably
00025 // drive the LCD.
00026 N5110::N5110(PinName const scePin,
00027              PinName const rstPin,
00028              PinName const dcPin,
00029              PinName const mosiPin,
00030              PinName const sclkPin,
00031              PinName const ledPin)
00032     :
00033     _spi(new SPI(mosiPin,NC,sclkPin)), // create new SPI instance and initialise
00034     _led(new PwmOut(ledPin)),
00035     _pwr(NULL), // pwr not needed so null it to be safe
00036     _sce(new DigitalOut(scePin)),
00037     _rst(new DigitalOut(rstPin)),
00038     _dc(new DigitalOut(dcPin))
00039 {}
00040  
00041 N5110::~N5110()
00042 {
00043     delete _spi;
00044  
00045     if(_pwr) {
00046         delete _pwr;
00047     }
00048  
00049     delete _led;
00050     delete _sce;
00051     delete _rst;
00052     delete _dc;
00053 }
00054  
00055 // initialise function - powers up and sends the initialisation commands
00056 void N5110::init()
00057 {
00058     turnOn();     // power up
00059     reset();      // reset LCD - must be done within 100 ms
00060  
00061     initSPI();
00062     // function set - extended
00063     sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);
00064     // Don't completely understand these parameters - they seem to work as they are
00065     // Consult the datasheet if you need to change them
00066     sendCommand(CMD_VOP_7V38);    // operating voltage - these values are from Chris Yan's Library
00067     sendCommand(CMD_TC_TEMP_2);   // temperature control
00068     sendCommand(CMD_BI_MUX_48);   // changing this can sometimes improve the contrast on some displays
00069  
00070     // function set - basic
00071     sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);
00072     normalMode();  // normal video mode by default
00073     sendCommand(CMD_DC_NORMAL_MODE);  // black on white
00074  
00075     clearRAM();      // RAM is undefined at power-up so clear
00076     clear();   // clear buffer
00077     setBrightness(0.5);
00078 }
00079  
00080 // sets normal video mode (black on white)
00081 void N5110::normalMode()
00082 {
00083     sendCommand(CMD_DC_NORMAL_MODE);
00084 }
00085  
00086 // sets normal video mode (white on black)
00087 void N5110::inverseMode()
00088 {
00089     sendCommand(CMD_DC_INVERT_VIDEO);
00090 }
00091  
00092 // function to power up the LCD and backlight - only works when using GPIO to power
00093 void N5110::turnOn()
00094 {
00095     if (_pwr != NULL) {
00096         _pwr->write(1);  // apply power
00097     }
00098 }
00099  
00100 // function to power down LCD
00101 void N5110::turnOff()
00102 {
00103     clear(); // clear buffer
00104     refresh();
00105     setBrightness(0.0);  // turn backlight off
00106     clearRAM();   // clear RAM to ensure specified current consumption
00107     // send command to ensure we are in basic mode
00108     sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);
00109     // clear the display
00110     sendCommand(CMD_DC_CLEAR_DISPLAY);
00111     // enter the extended mode and power down
00112     sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);
00113     // small delay and then turn off the power pin
00114     wait_ms(10);
00115  
00116     // if we are powering the LCD using the GPIO then make it low to turn off
00117     if (_pwr != NULL) {
00118         _pwr->write(0);  // turn off power
00119     }
00120  
00121 }
00122  
00123 // function to change LED backlight brightness
00124 void N5110::setBrightness(float brightness)
00125 {
00126     // check whether brightness is within range
00127     if (brightness < 0.0f)
00128         brightness = 0.0f;
00129     if (brightness > 1.0f)
00130         brightness = 1.0f;
00131     // set PWM duty cycle
00132     _led->write(brightness);
00133 }
00134  void N5110::setContrast(float contrast) {
00135     
00136     // enforce limits
00137     if (contrast > 1.0f)
00138         contrast = 1.0f;
00139     else if (contrast < 0.0f)
00140         contrast = 0.0;
00141     
00142     // convert to char in range 0 to 127 (i.e. 6 bits)
00143     char ic = char(contrast*127.0f);
00144     
00145     sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);  // extended instruction set
00146     sendCommand(0b10000000 | ic);   // set Vop (which controls contrast)
00147     sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);  // back to basic instruction set
00148 }
00149  
00150  void N5110::setTempCoefficient(char tc) {
00151     
00152     // enforce limits
00153     if (tc>3) {
00154         tc=3;
00155     }
00156     
00157     // temperature coefficient may need increasing at low temperatures
00158  
00159     sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);  // extended instruction set
00160     sendCommand(0b00000100 | tc);
00161     sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);  // back to basic instruction set
00162 }
00163 
00164 void N5110::setBias(char bias) {
00165     
00166     // from data sheet
00167     // bias      mux rate
00168     // 0        1:100
00169     // 1        1:80
00170     // 2        1:65
00171     // 3        1:48   (default)
00172     // 4        1:40/1:34
00173     // 5        1:24
00174     // 6        1:18/1:16
00175     // 7        1:10/1:9/1:8
00176     
00177     // enforce limits
00178     if (bias>7) {
00179         bias=7;
00180     }
00181         
00182     sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);  // extended mode instruction
00183     sendCommand(0b00010000 | bias);  
00184     sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE); // end of extended mode instruction
00185 }
00186 
00187 // pulse the active low reset line
00188 void N5110::reset()
00189 {
00190     _rst->write(0);  // reset the LCD
00191     _rst->write(1);
00192 }
00193  
00194 // function to initialise SPI peripheral
00195 void N5110::initSPI()
00196 {
00197     _spi->format(8,1);    // 8 bits, Mode 1 - polarity 0, phase 1 - base value of clock is 0, data captured on falling edge/propagated on rising edge
00198     _spi->frequency(4000000);  // maximum of screen is 4 MHz
00199 }
00200  
00201 // send a command to the display
00202 void N5110::sendCommand(unsigned char command)
00203 {
00204     _dc->write(0);  // set DC low for command
00205     _sce->write(0); // set CE low to begin frame
00206     _spi->write(command);  // send command
00207     _dc->write(1);  // turn back to data by default
00208     _sce->write(1); // set CE high to end frame (expected for transmission of single byte)
00209 }
00210  
00211 // send data to the display at the current XY address
00212 // dc is set to 1 (i.e. data) after sending a command and so should
00213 // be the default mode.
00214 void N5110::sendData(unsigned char data)
00215 {
00216     _sce->write(0);   // set CE low to begin frame
00217     _spi->write(data);
00218     _sce->write(1);  // set CE high to end frame (expected for transmission of single byte)
00219 }
00220  
00221 // this function writes 0 to the 504 bytes to clear the RAM
00222 void N5110::clearRAM()
00223 {
00224     _sce->write(0);  //set CE low to begin frame
00225     for(int i = 0; i < WIDTH * HEIGHT; i++) { // 48 x 84 bits = 504 bytes
00226         _spi->write(0x00);  // send 0's
00227     }
00228     _sce->write(1); // set CE high to end frame
00229 }
00230  
00231 // function to set the XY address in RAM for subsequenct data write
00232 void N5110::setXYAddress(unsigned int const x,
00233                          unsigned int const y)
00234 {
00235     if (x<WIDTH && y<HEIGHT) {  // check within range
00236         sendCommand(0x80 | x);  // send addresses to display with relevant mask
00237         sendCommand(0x40 | y);
00238     }
00239 }
00240  
00241 // These functions are used to set, clear and get the value of pixels in the display
00242 // Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x).  The refresh()
00243 // function must be called after set and clear in order to update the display
00244 void N5110::setPixel(unsigned int const x,
00245                      unsigned int const y,
00246                      bool const         state)
00247 {
00248     if (x<WIDTH && y<HEIGHT) {  // check within range
00249         // calculate bank and shift 1 to required position in the data byte
00250         if(state) buffer[x][y/8] |= (1 << y%8);
00251         else      buffer[x][y/8] &= ~(1 << y%8);
00252     }
00253 }
00254  
00255 void N5110::clearPixel(unsigned int const x,
00256                        unsigned int const y)
00257 {
00258     if (x<WIDTH && y<HEIGHT) {  // check within range
00259         // calculate bank and shift 1 to required position (using bit clear)
00260         buffer[x][y/8] &= ~(1 << y%8);
00261     }
00262 }
00263  
00264 int N5110::getPixel(unsigned int const x,
00265                     unsigned int const y) const
00266 {
00267     if (x<WIDTH && y<HEIGHT) {  // check within range
00268         // return relevant bank and mask required bit
00269  
00270         int pixel = (int) buffer[x][y/8] & (1 << y%8);
00271  
00272         if (pixel)
00273             return 1;
00274         else
00275             return 0;
00276     }
00277  
00278     return 0;
00279  
00280 }
00281  
00282 // function to refresh the display
00283 void N5110::refresh()
00284 {
00285     setXYAddress(0,0);  // important to set address back to 0,0 before refreshing display
00286     // address auto increments after printing string, so buffer[0][0] will not coincide
00287     // with top-left pixel after priting string
00288  
00289     _sce->write(0);  //set CE low to begin frame
00290  
00291     for(int j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
00292         for(int i = 0; i < WIDTH; i++) {
00293             _spi->write(buffer[i][j]);  // send buffer
00294         }
00295     }
00296     _sce->write(1); // set CE high to end frame
00297  
00298 }
00299  
00300 // fills the buffer with random bytes.  Can be used to test the display.
00301 // The rand() function isn't seeded so it probably creates the same pattern everytime
00302 void N5110::randomiseBuffer()
00303 {
00304     int i,j;
00305     for(j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
00306         for(i = 0; i < WIDTH; i++) {
00307             buffer[i][j] = rand()%256;  // generate random byte
00308         }
00309     }
00310  
00311 }
00312  
00313 // function to print 5x7 font
00314 void N5110::printChar(char const          c,
00315                       unsigned int const  x,
00316                       unsigned int const  y)
00317 {
00318     if (y<BANKS) {  // check if printing in range of y banks
00319  
00320         for (int i = 0; i < 5 ; i++ ) {
00321             int pixel_x = x+i;
00322             if (pixel_x > WIDTH-1)  // ensure pixel isn't outside the buffer size (0 - 83)
00323                 break;
00324             buffer[pixel_x][y] = font5x7[(c - 32)*5 + i];
00325             // array is offset by 32 relative to ASCII, each character is 5 pixels wide
00326         }
00327  
00328     }
00329 }
00330  
00331 // function to print string at specified position
00332 void N5110::printString(const char         *str,
00333                         unsigned int const  x,
00334                         unsigned int const  y)
00335 {
00336     if (y<BANKS) {  // check if printing in range of y banks
00337  
00338         int n = 0 ; // counter for number of characters in string
00339         // loop through string and print character
00340         while(*str) {
00341  
00342             // writes the character bitmap data to the buffer, so that
00343             // text and pixels can be displayed at the same time
00344             for (int i = 0; i < 5 ; i++ ) {
00345                 int pixel_x = x+i+n*6;
00346                 if (pixel_x > WIDTH-1) // ensure pixel isn't outside the buffer size (0 - 83)
00347                     break;
00348                 buffer[pixel_x][y] = font5x7[(*str - 32)*5 + i];
00349             }
00350             str++;  // go to next character in string
00351             n++;    // increment index
00352         }
00353     }
00354 }
00355  
00356 // function to clear the screen buffer
00357 void N5110::clear()
00358 {
00359     memset(buffer,0,sizeof(buffer));
00360 }
00361  
00362 // function to plot array on display
00363 void N5110::plotArray(float const array[])
00364 {
00365     for (int i=0; i<WIDTH; i++) {  // loop through array
00366         // elements are normalised from 0.0 to 1.0, so multiply
00367         // by 47 to convert to pixel range, and subtract from 47
00368         // since top-left is 0,0 in the display geometry
00369         setPixel(i,47 - int(array[i]*47.0f),true);
00370     }
00371  
00372 }
00373  
00374 // function to draw circle
00375 void N5110:: drawCircle(unsigned int const x0,
00376                         unsigned int const y0,
00377                         unsigned int const radius,
00378                         FillType const     fill)
00379 {
00380     // from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
00381     int x = radius;
00382     int y = 0;
00383     int radiusError = 1-x;
00384  
00385     while(x >= y) {
00386  
00387         // if transparent, just draw outline
00388         if (fill == FILL_TRANSPARENT) {
00389             setPixel( x + x0,  y + y0,true);
00390             setPixel(-x + x0,  y + y0,true);
00391             setPixel( y + x0,  x + y0,true);
00392             setPixel(-y + x0,  x + y0,true);
00393             setPixel(-y + x0, -x + y0,true);
00394             setPixel( y + x0, -x + y0,true);
00395             setPixel( x + x0, -y + y0,true);
00396             setPixel(-x + x0, -y + y0,true);
00397         } else {  // drawing filled circle, so draw lines between points at same y value
00398  
00399             int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
00400  
00401             drawLine(x+x0,y+y0,-x+x0,y+y0,type);
00402             drawLine(y+x0,x+y0,-y+x0,x+y0,type);
00403             drawLine(y+x0,-x+y0,-y+x0,-x+y0,type);
00404             drawLine(x+x0,-y+y0,-x+x0,-y+y0,type);
00405         }
00406  
00407         y++;
00408         if (radiusError<0) {
00409             radiusError += 2 * y + 1;
00410         } else {
00411             x--;
00412             radiusError += 2 * (y - x) + 1;
00413         }
00414     }
00415  
00416 }
00417  
00418 void N5110::drawLine(unsigned int const x0,
00419                      unsigned int const y0,
00420                      unsigned int const x1,
00421                      unsigned int const y1,
00422                      unsigned int const type)
00423 {
00424     int y_range = static_cast<int>(y1) - static_cast<int>(y0); // calc range of y and x
00425     int x_range = static_cast<int>(x1) - static_cast<int>(x0);
00426  
00427     // if dotted line, set step to 2, else step is 1
00428     unsigned int const step = (type==2) ? 2:1;
00429  
00430     // make sure we loop over the largest range to get the most pixels on the display
00431     // for instance, if drawing a vertical line (x_range = 0), we need to loop down the y pixels
00432     // or else we'll only end up with 1 pixel in the x column
00433     if ( abs(x_range) > abs(y_range) ) {
00434  
00435         // ensure we loop from smallest to largest or else for-loop won't run as expected
00436         unsigned int const start = x_range > 0 ? x0:x1;
00437         unsigned int const stop =  x_range > 0 ? x1:x0;
00438  
00439         // loop between x pixels
00440         for (int x = start; x<= stop ; x+=step) {
00441             // do linear interpolation
00442             int const x_change = static_cast<int>(x)-static_cast<int>(x0);
00443             unsigned int const y = y0 + y_range * x_change / x_range;
00444  
00445             if (type == 0)   // if 'white' line, turn off pixel
00446                 clearPixel(x,y);
00447             else
00448                 setPixel(x,y,type);  // else if 'black' or 'dotted' turn on pixel
00449         }
00450     } else {
00451  
00452         // ensure we loop from smallest to largest or else for-loop won't run as expected
00453         unsigned int const start = y_range > 0 ? y0:y1;
00454         unsigned int const stop =  y_range > 0 ? y1:y0;
00455  
00456         for (int y = start; y<= stop ; y+=step) {
00457             // do linear interpolation
00458             int const y_change = static_cast<int>(y)-static_cast<int>(y0);
00459             unsigned int const x = x0 + x_range * y_change / y_range;
00460  
00461             if (type == 0)   // if 'white' line, turn off pixel
00462                 clearPixel(x,y);
00463             else
00464                 setPixel(x,y,type);  // else if 'black' or 'dotted' turn on pixel
00465  
00466         }
00467     }
00468  
00469 }
00470  
00471 void N5110::drawRect(unsigned int const x0,
00472                      unsigned int const y0,
00473                      unsigned int const width,
00474                      unsigned int const height,
00475                      FillType const     fill)
00476 {
00477     if (fill == FILL_TRANSPARENT) { // transparent, just outline
00478         drawLine(x0,y0,x0+(width-1),y0,1);  // top
00479         drawLine(x0,y0+(height-1),x0+(width-1),y0+(height-1),1);  // bottom
00480         drawLine(x0,y0,x0,y0+(height-1),1);  // left
00481         drawLine(x0+(width-1),y0,x0+(width-1),y0+(height-1),1);  // right
00482     } else { // filled rectangle
00483         int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
00484         for (int y = y0; y<y0+height; y++) {  // loop through rows of rectangle
00485             drawLine(x0,y,x0+(width-1),y,type);  // draw line across screen
00486         }
00487     }
00488 }
00489 
00490 void N5110::drawSprite(int x0,
00491                        int y0,
00492                        int nrows,
00493                        int ncols,
00494                        int *sprite)
00495 {
00496     for (int i = 0; i < nrows; i++) {
00497         for (int j = 0 ; j < ncols ; j++) {
00498  
00499             int pixel = *((sprite+i*ncols)+j);
00500             setPixel(x0+j,y0+i, pixel);
00501         }
00502     }
00503 }