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