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     initSPI();    
00061     
00062     setContrast(0.55);  // this may need tuning (say 0.4 to 0.6)
00063     setBias(3);   // datasheet - 48:1 mux - don't mess with if you don't know what you're doing! (0 to 7)
00064     setTempCoefficient(0); // datasheet - may need increasing (range 0 to 3) at very low temperatures
00065     normalMode();  // normal video mode by default
00066     
00067     clearRAM();      // RAM is undefined at power-up so clear to be sure
00068     clear();   // clear buffer
00069     setBrightness(0.5);
00070 }
00071 
00072 // sets normal video mode (black on white)
00073 void N5110::normalMode()
00074 {
00075     sendCommand(0b00100000);   // basic instruction
00076     sendCommand(0b00001100);  // normal video mode- datasheet
00077 }
00078 
00079 // sets normal video mode (white on black)
00080 void N5110::inverseMode()
00081 {
00082     sendCommand(0b00100000);   // basic instruction
00083     sendCommand(0b00001101);   // inverse video mode - datasheet
00084 }
00085 
00086 // function to power up the LCD and backlight - only works when using GPIO to power
00087 void N5110::turnOn()
00088 {
00089     if (_pwr != NULL) {
00090         _pwr->write(1);  // apply power
00091     }
00092 }
00093 
00094 // function to power down LCD
00095 void N5110::turnOff()
00096 {
00097     clear(); // clear buffer
00098     refresh();
00099     setBrightness(0.0);  // turn backlight off
00100     clearRAM();   // clear RAM to ensure specified current consumption
00101     // send command to ensure we are in basic mode
00102     
00103     sendCommand(0b00100000); // basic mode
00104     sendCommand(0b00001000); // clear display
00105     sendCommand(0b00100001); // extended mode
00106     sendCommand(0b00100100); // power down
00107     
00108     // if we are powering the LCD using the GPIO then make it low to turn off
00109     if (_pwr != NULL) {
00110         wait_ms(10);  // small delay and then turn off the power pin
00111         _pwr->write(0);  // turn off power
00112     }
00113 
00114 }
00115 
00116 // function to change LED backlight brightness
00117 void N5110::setBrightness(float brightness)
00118 {
00119     // check whether brightness is within range
00120     if (brightness < 0.0f)
00121         brightness = 0.0f;
00122     if (brightness > 1.0f)
00123         brightness = 1.0f;
00124     // set PWM duty cycle
00125     _led->write(brightness);
00126 }
00127 
00128 void N5110::setContrast(float contrast) {
00129     
00130     // enforce limits
00131     if (contrast > 1.0f)
00132         contrast = 1.0f;
00133     else if (contrast < 0.0f)
00134         contrast = 0.0;
00135     
00136     // convert to char in range 0 to 127 (i.e. 6 bits)
00137     char ic = char(contrast*127.0f);
00138     
00139     sendCommand(0b00100001);  // extended instruction set
00140     sendCommand(0b10000000 | ic);   // set Vop (which controls contrast)
00141     sendCommand(0b00100000);  // back to basic instruction set
00142 }
00143 
00144 void N5110::setTempCoefficient(char tc) {
00145     
00146     // enforce limits
00147     if (tc>3) {
00148         tc=3;
00149     }
00150     
00151     // temperature coefficient may need increasing at low temperatures
00152 
00153     sendCommand(0b00100001);  // extended instruction set
00154     sendCommand(0b00000100 | tc);
00155     sendCommand(0b00100000);  // back to basic instruction set
00156 }
00157     
00158 void N5110::setBias(char bias) {
00159     
00160     // from data sheet
00161     // bias      mux rate
00162     // 0        1:100
00163     // 1        1:80
00164     // 2        1:65
00165     // 3        1:48   (default)
00166     // 4        1:40/1:34
00167     // 5        1:24
00168     // 6        1:18/1:16
00169     // 7        1:10/1:9/1:8
00170     
00171     // enforce limits
00172     if (bias>7) {
00173         bias=7;
00174     }
00175         
00176     sendCommand(0b00100001);  // extended mode instruction
00177     sendCommand(0b00010000 | bias);  
00178     sendCommand(0b00100000); // end of extended mode instruction
00179 }
00180 
00181 // pulse the active low reset line
00182 void N5110::reset()
00183 {
00184     _rst->write(0);  // reset the LCD
00185     _rst->write(1);
00186 }
00187 
00188 // function to initialise SPI peripheral
00189 void N5110::initSPI()
00190 {
00191     _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
00192     _spi->frequency(4000000);  // maximum of screen is 4 MHz
00193 }
00194 
00195 // send a command to the display
00196 void N5110::sendCommand(unsigned char command)
00197 {
00198     _dc->write(0);  // set DC low for command
00199     _sce->write(0); // set CE low to begin frame
00200     _spi->write(command);  // send command
00201     _dc->write(1);  // turn back to data by default
00202     _sce->write(1); // set CE high to end frame (expected for transmission of single byte)
00203 }
00204 
00205 // send data to the display at the current XY address
00206 // dc is set to 1 (i.e. data) after sending a command and so should
00207 // be the default mode.
00208 void N5110::sendData(unsigned char data)
00209 {
00210     _sce->write(0);   // set CE low to begin frame
00211     _spi->write(data);
00212     _sce->write(1);  // set CE high to end frame (expected for transmission of single byte)
00213 }
00214 
00215 // this function writes 0 to the 504 bytes to clear the RAM
00216 void N5110::clearRAM()
00217 {
00218     _sce->write(0);  //set CE low to begin frame
00219     for(int i = 0; i < WIDTH * HEIGHT; i++) { // 48 x 84 bits = 504 bytes
00220         _spi->write(0x00);  // send 0's
00221     }
00222     _sce->write(1); // set CE high to end frame
00223 }
00224 
00225 // function to set the XY address in RAM for subsequenct data write
00226 void N5110::setXYAddress(unsigned int const x,
00227                          unsigned int const y)
00228 {
00229     if (x<WIDTH && y<HEIGHT) {  // check within range
00230         sendCommand(0b00100000);  // basic instruction
00231         sendCommand(0b10000000 | x);  // send addresses to display with relevant mask
00232         sendCommand(0b01000000 | y);
00233     }
00234 }
00235 
00236 // These functions are used to set, clear and get the value of pixels in the display
00237 // Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x).  The refresh()
00238 // function must be called after set and clear in order to update the display
00239 void N5110::setPixel(unsigned int const x,
00240                      unsigned int const y,
00241                      bool const         state)
00242 {
00243     if (x<WIDTH && y<HEIGHT) {  // check within range
00244         // calculate bank and shift 1 to required position in the data byte
00245         if(state) buffer[x][y/8] |= (1 << y%8);
00246         else      buffer[x][y/8] &= ~(1 << y%8);
00247         
00248     }
00249 }
00250 
00251 void N5110::setScreen(unsigned char data[84][6]){
00252     for(int i=0; i<84; i++){
00253         for(int j=0; j<6; j++){
00254             buffer[i][j] &= (unsigned char)data[i][j];
00255             buffer[i][j] |= (unsigned char)data[i][j];
00256         }
00257     }
00258 }
00259 
00260 void N5110::clearPixel(unsigned int const x,
00261                        unsigned int const y)
00262 {
00263     if (x<WIDTH && y<HEIGHT) {  // check within range
00264         // calculate bank and shift 1 to required position (using bit clear)
00265         buffer[x][y/8] &= ~(1 << y%8);
00266     }
00267 }
00268 
00269 int N5110::getPixel(unsigned int const x,
00270                     unsigned int const y) const
00271 {
00272     if (x<WIDTH && y<HEIGHT) {  // check within range
00273         // return relevant bank and mask required bit
00274 
00275         int pixel = (int) buffer[x][y/8] & (1 << y%8);
00276 
00277         if (pixel)
00278             return 1;
00279         else
00280             return 0;
00281     }
00282 
00283     return 0;
00284 
00285 }
00286 
00287 // function to refresh the display
00288 void N5110::refresh()
00289 {
00290     setXYAddress(0,0);  // important to set address back to 0,0 before refreshing display
00291     // address auto increments after printing string, so buffer[0][0] will not coincide
00292     // with top-left pixel after priting string
00293 
00294     _sce->write(0);  //set CE low to begin frame
00295 
00296     for(int j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
00297         for(int i = 0; i < WIDTH; i++) {
00298             _spi->write(buffer[i][j]);  // send buffer
00299         }
00300     }
00301     _sce->write(1); // set CE high to end frame
00302 
00303 }
00304 
00305 // fills the buffer with random bytes.  Can be used to test the display.
00306 // The rand() function isn't seeded so it probably creates the same pattern everytime
00307 void N5110::randomiseBuffer()
00308 {
00309     int i,j;
00310     for(j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
00311         for(i = 0; i < WIDTH; i++) {
00312             buffer[i][j] = rand()%256;  // generate random byte
00313         }
00314     }
00315 
00316 }
00317 
00318 // function to print 5x7 font
00319 void N5110::printChar(char const          c,
00320                       unsigned int const  x,
00321                       unsigned int const  y)
00322 {
00323     if (y<BANKS) {  // check if printing in range of y banks
00324 
00325         for (int i = 0; i < 5 ; i++ ) {
00326             int pixel_x = x+i;
00327             if (pixel_x > WIDTH-1)  // ensure pixel isn't outside the buffer size (0 - 83)
00328                 break;
00329             buffer[pixel_x][y] = font5x7[(c - 32)*5 + i];
00330             // array is offset by 32 relative to ASCII, each character is 5 pixels wide
00331         }
00332 
00333     }
00334 }
00335 
00336 // function to print string at specified position
00337 void N5110::printString(const char         *str,
00338                         unsigned int const  x,
00339                         unsigned int const  y)
00340 {
00341     if (y<BANKS) {  // check if printing in range of y banks
00342 
00343         int n = 0 ; // counter for number of characters in string
00344         // loop through string and print character
00345         while(*str) {
00346 
00347             // writes the character bitmap data to the buffer, so that
00348             // text and pixels can be displayed at the same time
00349             for (int i = 0; i < 5 ; i++ ) {
00350                 int pixel_x = x+i+n*6;
00351                 if (pixel_x > WIDTH-1) // ensure pixel isn't outside the buffer size (0 - 83)
00352                     break;
00353                 buffer[pixel_x][y] = font5x7[(*str - 32)*5 + i];
00354             }
00355             str++;  // go to next character in string
00356             n++;    // increment index
00357         }
00358     }
00359 }
00360 
00361 // function to clear the screen buffer
00362 void N5110::clear()
00363 {
00364     memset(buffer,0,sizeof(buffer));
00365 }
00366 
00367 // function to plot array on display
00368 void N5110::plotArray(float const array[])
00369 {
00370     for (int i=0; i<WIDTH; i++) {  // loop through array
00371         // elements are normalised from 0.0 to 1.0, so multiply
00372         // by 47 to convert to pixel range, and subtract from 47
00373         // since top-left is 0,0 in the display geometry
00374         setPixel(i,47 - int(array[i]*47.0f),true);
00375     }
00376 
00377 }
00378 
00379 // function to draw circle
00380 void N5110:: drawCircle(unsigned int const x0,
00381                         unsigned int const y0,
00382                         unsigned int const radius,
00383                         FillType const     fill)
00384 {
00385     // from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
00386     int x = radius;
00387     int y = 0;
00388     int radiusError = 1-x;
00389 
00390     while(x >= y) {
00391 
00392         // if transparent, just draw outline
00393         if (fill == FILL_TRANSPARENT) {
00394             setPixel( x + x0,  y + y0,true);
00395             setPixel(-x + x0,  y + y0,true);
00396             setPixel( y + x0,  x + y0,true);
00397             setPixel(-y + x0,  x + y0,true);
00398             setPixel(-y + x0, -x + y0,true);
00399             setPixel( y + x0, -x + y0,true);
00400             setPixel( x + x0, -y + y0,true);
00401             setPixel(-x + x0, -y + y0,true);
00402         } else {  // drawing filled circle, so draw lines between points at same y value
00403 
00404             int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
00405 
00406             drawLine(x+x0,y+y0,-x+x0,y+y0,type);
00407             drawLine(y+x0,x+y0,-y+x0,x+y0,type);
00408             drawLine(y+x0,-x+y0,-y+x0,-x+y0,type);
00409             drawLine(x+x0,-y+y0,-x+x0,-y+y0,type);
00410         }
00411 
00412         y++;
00413         if (radiusError<0) {
00414             radiusError += 2 * y + 1;
00415         } else {
00416             x--;
00417             radiusError += 2 * (y - x) + 1;
00418         }
00419     }
00420 
00421 }
00422 
00423 void N5110::drawLine(unsigned int const x0,
00424                      unsigned int const y0,
00425                      unsigned int const x1,
00426                      unsigned int const y1,
00427                      unsigned int const type)
00428 {
00429     // Note that the ranges can be negative so we have to turn the input values
00430     // into signed integers first
00431     int const y_range = static_cast<int>(y1) - static_cast<int>(y0);
00432     int const x_range = static_cast<int>(x1) - static_cast<int>(x0);
00433 
00434     // if dotted line, set step to 2, else step is 1
00435     unsigned int const step = (type==2) ? 2:1;
00436 
00437     // make sure we loop over the largest range to get the most pixels on the display
00438     // for instance, if drawing a vertical line (x_range = 0), we need to loop down the y pixels
00439     // or else we'll only end up with 1 pixel in the x column
00440     if ( abs(x_range) > abs(y_range) ) {
00441 
00442         // ensure we loop from smallest to largest or else for-loop won't run as expected
00443         unsigned int const start = x_range > 0 ? x0:x1;
00444         unsigned int const stop =  x_range > 0 ? x1:x0;
00445 
00446         // loop between x pixels
00447         for (unsigned int x = start; x<= stop ; x+=step) {
00448             // do linear interpolation
00449             int const dx = static_cast<int>(x)-static_cast<int>(x0);
00450             unsigned int const y = y0 + y_range * dx / x_range;
00451 
00452             // If the line type is '0', this will clear the pixel
00453             // If it is '1' or '2', the pixel will be set
00454             setPixel(x,y, type);
00455         }
00456     } else {
00457 
00458         // ensure we loop from smallest to largest or else for-loop won't run as expected
00459         unsigned int const start = y_range > 0 ? y0:y1;
00460         unsigned int const stop =  y_range > 0 ? y1:y0;
00461 
00462         for (unsigned int y = start; y<= stop ; y+=step) {
00463             // do linear interpolation
00464             int const dy = static_cast<int>(y)-static_cast<int>(y0);
00465             unsigned int const x = x0 + x_range * dy / y_range;
00466 
00467             // If the line type is '0', this will clear the pixel
00468             // If it is '1' or '2', the pixel will be set
00469             setPixel(x,y, type);
00470         }
00471     }
00472 
00473 }
00474 
00475 void N5110::drawRect(unsigned int const x0,
00476                      unsigned int const y0,
00477                      unsigned int const width,
00478                      unsigned int const height,
00479                      FillType const     fill)
00480 {
00481     if (fill == FILL_TRANSPARENT) { // transparent, just outline
00482         drawLine(x0,y0,x0+(width-1),y0,1);  // top
00483         drawLine(x0,y0+(height-1),x0+(width-1),y0+(height-1),1);  // bottom
00484         drawLine(x0,y0,x0,y0+(height-1),1);  // left
00485         drawLine(x0+(width-1),y0,x0+(width-1),y0+(height-1),1);  // right
00486     } else { // filled rectangle
00487         int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
00488         for (int y = y0; y<y0+height; y++) {  // loop through rows of rectangle
00489             drawLine(x0,y,x0+(width-1),y,type);  // draw line across screen
00490         }
00491     }
00492 }
00493 
00494 void N5110::drawSprite(int x0,
00495                        int y0,
00496                        int nrows,
00497                        int ncols,
00498                        int *sprite)
00499 {
00500     for (int i = 0; i < nrows; i++) {
00501         for (int j = 0 ; j < ncols ; j++) {
00502 
00503             int pixel = *((sprite+i*ncols)+j);
00504             setPixel(x0+j,y0+i, pixel);
00505         }
00506     }
00507 }