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 
00135 
00136 // pulse the active low reset line
00137 void N5110::reset()
00138 {
00139     _rst->write(0);  // reset the LCD
00140     _rst->write(1);
00141 }
00142 
00143 // function to initialise SPI peripheral
00144 void N5110::initSPI()
00145 {
00146     _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
00147     _spi->frequency(4000000);  // maximum of screen is 4 MHz
00148 }
00149 
00150 // send a command to the display
00151 void N5110::sendCommand(unsigned char command)
00152 {
00153     _dc->write(0);  // set DC low for command
00154     _sce->write(0); // set CE low to begin frame
00155     _spi->write(command);  // send command
00156     _dc->write(1);  // turn back to data by default
00157     _sce->write(1); // set CE high to end frame (expected for transmission of single byte)
00158 }
00159 
00160 // send data to the display at the current XY address
00161 // dc is set to 1 (i.e. data) after sending a command and so should
00162 // be the default mode.
00163 void N5110::sendData(unsigned char data)
00164 {
00165     _sce->write(0);   // set CE low to begin frame
00166     _spi->write(data);
00167     _sce->write(1);  // set CE high to end frame (expected for transmission of single byte)
00168 }
00169 
00170 // this function writes 0 to the 504 bytes to clear the RAM
00171 void N5110::clearRAM()
00172 {
00173     _sce->write(0);  //set CE low to begin frame
00174     for(int i = 0; i < WIDTH * HEIGHT; i++) { // 48 x 84 bits = 504 bytes
00175         _spi->write(0x00);  // send 0's
00176     }
00177     _sce->write(1); // set CE high to end frame
00178 }
00179 
00180 // function to set the XY address in RAM for subsequenct data write
00181 void N5110::setXYAddress(unsigned int const x,
00182                          unsigned int const y)
00183 {
00184     if (x<WIDTH && y<HEIGHT) {  // check within range
00185         sendCommand(0x80 | x);  // send addresses to display with relevant mask
00186         sendCommand(0x40 | y);
00187     }
00188 }
00189 
00190 // These functions are used to set, clear and get the value of pixels in the display
00191 // Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x).  The refresh()
00192 // function must be called after set and clear in order to update the display
00193 void N5110::setPixel(unsigned int const x,
00194                      unsigned int const y)
00195 {
00196     if (x<WIDTH && y<HEIGHT) {  // check within range
00197         // calculate bank and shift 1 to required position in the data byte
00198         buffer[x][y/8] |= (1 << y%8);
00199     }
00200 }
00201 
00202 void N5110::clearPixel(unsigned int const x,
00203                        unsigned int const y)
00204 {
00205     if (x<WIDTH && y<HEIGHT) {  // check within range
00206         // calculate bank and shift 1 to required position (using bit clear)
00207         buffer[x][y/8] &= ~(1 << y%8);
00208     }
00209 }
00210 
00211 int N5110::getPixel(unsigned int const x,
00212                     unsigned int const y) const
00213 {
00214     if (x<WIDTH && y<HEIGHT) {  // check within range
00215         // return relevant bank and mask required bit
00216 
00217         int pixel = (int) buffer[x][y/8] & (1 << y%8);
00218 
00219         if (pixel)
00220             return 1;
00221         else
00222             return 0;
00223     }
00224 
00225     return 0;
00226 
00227 }
00228 
00229 // function to refresh the display
00230 void N5110::refresh()
00231 {
00232     setXYAddress(0,0);  // important to set address back to 0,0 before refreshing display
00233     // address auto increments after printing string, so buffer[0][0] will not coincide
00234     // with top-left pixel after priting string
00235 
00236     _sce->write(0);  //set CE low to begin frame
00237 
00238     for(int j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
00239         for(int i = 0; i < WIDTH; i++) {
00240             _spi->write(buffer[i][j]);  // send buffer
00241         }
00242     }
00243     _sce->write(1); // set CE high to end frame
00244 
00245 }
00246 
00247 // fills the buffer with random bytes.  Can be used to test the display.
00248 // The rand() function isn't seeded so it probably creates the same pattern everytime
00249 void N5110::randomiseBuffer()
00250 {
00251     int i,j;
00252     for(j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
00253         for(i = 0; i < WIDTH; i++) {
00254             buffer[i][j] = rand()%256;  // generate random byte
00255         }
00256     }
00257 
00258 }
00259 
00260 // function to print 5x7 font
00261 void N5110::printChar(char const          c,
00262                       unsigned int const  x,
00263                       unsigned int const  y)
00264 {
00265     if (y<BANKS) {  // check if printing in range of y banks
00266 
00267         for (int i = 0; i < 5 ; i++ ) {
00268             int pixel_x = x+i;
00269             if (pixel_x > WIDTH-1)  // ensure pixel isn't outside the buffer size (0 - 83)
00270                 break;
00271             buffer[pixel_x][y] = font5x7[(c - 32)*5 + i];
00272             // array is offset by 32 relative to ASCII, each character is 5 pixels wide
00273         }
00274 
00275     }
00276 }
00277 
00278 // function to print string at specified position
00279 void N5110::printString(const char         *str,
00280                         unsigned int const  x,
00281                         unsigned int const  y)
00282 {
00283     if (y<BANKS) {  // check if printing in range of y banks
00284 
00285         int n = 0 ; // counter for number of characters in string
00286         // loop through string and print character
00287         while(*str) {
00288 
00289             // writes the character bitmap data to the buffer, so that
00290             // text and pixels can be displayed at the same time
00291             for (int i = 0; i < 5 ; i++ ) {
00292                 int pixel_x = x+i+n*6;
00293                 if (pixel_x > WIDTH-1) // ensure pixel isn't outside the buffer size (0 - 83)
00294                     break;
00295                 buffer[pixel_x][y] = font5x7[(*str - 32)*5 + i];
00296             }
00297             str++;  // go to next character in string
00298             n++;    // increment index
00299         }
00300     }
00301 }
00302 
00303 // function to clear the screen buffer
00304 void N5110::clear()
00305 {
00306     memset(buffer,0,sizeof(buffer));
00307 }
00308 
00309 // function to plot array on display
00310 void N5110::plotArray(float const array[])
00311 {
00312     for (int i=0; i<WIDTH; i++) {  // loop through array
00313         // elements are normalised from 0.0 to 1.0, so multiply
00314         // by 47 to convert to pixel range, and subtract from 47
00315         // since top-left is 0,0 in the display geometry
00316         setPixel(i,47 - int(array[i]*47.0f));
00317     }
00318 
00319 }
00320 
00321 // function to draw circle
00322 void N5110:: drawCircle(unsigned int const x0,
00323                         unsigned int const y0,
00324                         unsigned int const radius,
00325                         FillType const     fill)
00326 {
00327     // from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
00328     int x = radius;
00329     int y = 0;
00330     int radiusError = 1-x;
00331 
00332     while(x >= y) {
00333 
00334         // if transparent, just draw outline
00335         if (fill == FILL_TRANSPARENT) {
00336             setPixel( x + x0,  y + y0);
00337             setPixel(-x + x0,  y + y0);
00338             setPixel( y + x0,  x + y0);
00339             setPixel(-y + x0,  x + y0);
00340             setPixel(-y + x0, -x + y0);
00341             setPixel( y + x0, -x + y0);
00342             setPixel( x + x0, -y + y0);
00343             setPixel(-x + x0, -y + y0);
00344         } else {  // drawing filled circle, so draw lines between points at same y value
00345 
00346             int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
00347 
00348             drawLine(x+x0,y+y0,-x+x0,y+y0,type);
00349             drawLine(y+x0,x+y0,-y+x0,x+y0,type);
00350             drawLine(y+x0,-x+y0,-y+x0,-x+y0,type);
00351             drawLine(x+x0,-y+y0,-x+x0,-y+y0,type);
00352         }
00353 
00354         y++;
00355         if (radiusError<0) {
00356             radiusError += 2 * y + 1;
00357         } else {
00358             x--;
00359             radiusError += 2 * (y - x) + 1;
00360         }
00361     }
00362 
00363 }
00364 
00365 void N5110::drawLine(unsigned int const x0,
00366                      unsigned int const y0,
00367                      unsigned int const x1,
00368                      unsigned int const y1,
00369                      unsigned int const type)
00370 {
00371     int y_range = y1-y0;  // calc range of y and x
00372     int x_range = x1-x0;
00373     int start,stop,step;
00374 
00375     // if dotted line, set step to 2, else step is 1
00376     step = (type==2) ? 2:1;
00377 
00378     // make sure we loop over the largest range to get the most pixels on the display
00379     // for instance, if drawing a vertical line (x_range = 0), we need to loop down the y pixels
00380     // or else we'll only end up with 1 pixel in the x column
00381     if ( abs(x_range) > abs(y_range) ) {
00382 
00383         // ensure we loop from smallest to largest or else for-loop won't run as expected
00384         start = x1>x0 ? x0:x1;
00385         stop =  x1>x0 ? x1:x0;
00386 
00387         // loop between x pixels
00388         for (int x = start; x<= stop ; x+=step) {
00389             // do linear interpolation
00390             int y = y0 + (y1-y0)*(x-x0)/(x1-x0);
00391 
00392             if (type == 0)   // if 'white' line, turn off pixel
00393                 clearPixel(x,y);
00394             else
00395                 setPixel(x,y);  // else if 'black' or 'dotted' turn on pixel
00396         }
00397     } else {
00398 
00399         // ensure we loop from smallest to largest or else for-loop won't run as expected
00400         start = y1>y0 ? y0:y1;
00401         stop =  y1>y0 ? y1:y0;
00402 
00403         for (int y = start; y<= stop ; y+=step) {
00404             // do linear interpolation
00405             int x = x0 + (x1-x0)*(y-y0)/(y1-y0);
00406 
00407             if (type == 0)   // if 'white' line, turn off pixel
00408                 clearPixel(x,y);
00409             else
00410                 setPixel(x,y);  // else if 'black' or 'dotted' turn on pixel
00411 
00412         }
00413     }
00414 
00415 }
00416 
00417 void N5110::drawRect(unsigned int const x0,
00418                      unsigned int const y0,
00419                      unsigned int const width,
00420                      unsigned int const height,
00421                      FillType const     fill)
00422 {
00423     if (fill == FILL_TRANSPARENT) { // transparent, just outline
00424         drawLine(x0,y0,x0+(width-1),y0,1);  // top
00425         drawLine(x0,y0+(height-1),x0+(width-1),y0+(height-1),1);  // bottom
00426         drawLine(x0,y0,x0,y0+(height-1),1);  // left
00427         drawLine(x0+(width-1),y0,x0+(width-1),y0+(height-1),1);  // right
00428     } else { // filled rectangle
00429         int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
00430         for (int y = y0; y<y0+height; y++) {  // loop through rows of rectangle
00431             drawLine(x0,y,x0+(width-1),y,type);  // draw line across screen
00432         }
00433     }
00434 }
00435 
00436 void N5110::drawSprite(int x0,
00437                       int y0,
00438                       int nrows,
00439                       int ncols,
00440                       int *sprite)
00441 { 
00442     for (int i = 0; i < nrows; i++) {
00443         for (int j = 0 ; j < ncols ; j++) {
00444 
00445             int pixel = *((sprite+i*ncols)+j);
00446 
00447             if (pixel) {
00448                 setPixel(x0+j,y0+i);
00449             }
00450             else {
00451                 clearPixel(x0+j,y0+i);    
00452             }
00453 
00454         }
00455     }
00456 }