Diff: N5110/N5110.cpp

Revision:

13:08bdb4cffacd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110/N5110.cpp	Thu May 09 14:36:47 2019 +0000
@@ -0,0 +1,497 @@
+#include "mbed.h"
+#include "N5110.h"
+
+// overloaded constructor includes power pin - LCD Vcc connected to GPIO pin
+// this constructor works fine with LPC1768 - enough current sourced from GPIO
+// to power LCD. Doesn't work well with K64F.
+N5110::N5110(PinName const pwrPin,
+             PinName const scePin,
+             PinName const rstPin,
+             PinName const dcPin,
+             PinName const mosiPin,
+             PinName const sclkPin,
+             PinName const ledPin)
+    :
+    _spi(new SPI(mosiPin,NC,sclkPin)), // create new SPI instance and initialise
+    _led(new PwmOut(ledPin)),
+    _pwr(new DigitalOut(pwrPin)),
+    _sce(new DigitalOut(scePin)),
+    _rst(new DigitalOut(rstPin)),
+    _dc(new DigitalOut(dcPin))
+{}
+
+// overloaded constructor does not include power pin - LCD Vcc must be tied to +3V3
+// Best to use this with K64F as the GPIO hasn't sufficient output current to reliably
+// drive the LCD.
+N5110::N5110(PinName const scePin,
+             PinName const rstPin,
+             PinName const dcPin,
+             PinName const mosiPin,
+             PinName const sclkPin,
+             PinName const ledPin)
+    :
+    _spi(new SPI(mosiPin,NC,sclkPin)), // create new SPI instance and initialise
+    _led(new PwmOut(ledPin)),
+    _pwr(NULL), // pwr not needed so null it to be safe
+    _sce(new DigitalOut(scePin)),
+    _rst(new DigitalOut(rstPin)),
+    _dc(new DigitalOut(dcPin))
+{}
+
+N5110::~N5110()
+{
+    delete _spi;
+
+    if(_pwr) {
+        delete _pwr;
+    }
+
+    delete _led;
+    delete _sce;
+    delete _rst;
+    delete _dc;
+}
+
+// initialise function - powers up and sends the initialisation commands
+void N5110::init()
+{
+    turnOn();     // power up
+    reset();      // reset LCD - must be done within 100 ms
+    initSPI();    
+    
+    setContrast(0.55);  // this may need tuning (say 0.4 to 0.6)
+    setBias(3);   // datasheet - 48:1 mux - don't mess with if you don't know what you're doing! (0 to 7)
+    setTempCoefficient(0); // datasheet - may need increasing (range 0 to 3) at very low temperatures
+    normalMode();  // normal video mode by default
+    
+    clearRAM();      // RAM is undefined at power-up so clear to be sure
+    clear();   // clear buffer
+    setBrightness(0.5);
+}
+
+// sets normal video mode (black on white)
+void N5110::normalMode()
+{
+    sendCommand(0b00100000);   // basic instruction
+    sendCommand(0b00001100);  // normal video mode- datasheet
+}
+
+// sets normal video mode (white on black)
+void N5110::inverseMode()
+{
+    sendCommand(0b00100000);   // basic instruction
+    sendCommand(0b00001101);   // inverse video mode - datasheet
+}
+
+// function to power up the LCD and backlight - only works when using GPIO to power
+void N5110::turnOn()
+{
+    if (_pwr != NULL) {
+        _pwr->write(1);  // apply power
+    }
+}
+
+// function to power down LCD
+void N5110::turnOff()
+{
+    clear(); // clear buffer
+    refresh();
+    setBrightness(0.0);  // turn backlight off
+    clearRAM();   // clear RAM to ensure specified current consumption
+    // send command to ensure we are in basic mode
+    
+    sendCommand(0b00100000); // basic mode
+    sendCommand(0b00001000); // clear display
+    sendCommand(0b00100001); // extended mode
+    sendCommand(0b00100100); // power down
+    
+    // if we are powering the LCD using the GPIO then make it low to turn off
+    if (_pwr != NULL) {
+        wait_ms(10);  // small delay and then turn off the power pin
+        _pwr->write(0);  // turn off power
+    }
+
+}
+
+// function to change LED backlight brightness
+void N5110::setBrightness(float brightness)
+{
+    // check whether brightness is within range
+    if (brightness < 0.0f)
+        brightness = 0.0f;
+    if (brightness > 1.0f)
+        brightness = 1.0f;
+    // set PWM duty cycle
+    _led->write(brightness);
+}
+
+void N5110::setContrast(float contrast) {
+    
+    // enforce limits
+    if (contrast > 1.0f)
+        contrast = 1.0f;
+    else if (contrast < 0.0f)
+        contrast = 0.0;
+    
+    // convert to char in range 0 to 127 (i.e. 6 bits)
+    char ic = char(contrast*127.0f);
+    
+    sendCommand(0b00100001);  // extended instruction set
+    sendCommand(0b10000000 | ic);   // set Vop (which controls contrast)
+    sendCommand(0b00100000);  // back to basic instruction set
+}
+
+void N5110::setTempCoefficient(char tc) {
+    
+    // enforce limits
+    if (tc>3) {
+        tc=3;
+    }
+    
+    // temperature coefficient may need increasing at low temperatures
+
+    sendCommand(0b00100001);  // extended instruction set
+    sendCommand(0b00000100 | tc);
+    sendCommand(0b00100000);  // back to basic instruction set
+}
+    
+void N5110::setBias(char bias) {
+    
+    // from data sheet
+    // bias      mux rate
+    // 0        1:100
+    // 1        1:80
+    // 2        1:65
+    // 3        1:48   (default)
+    // 4        1:40/1:34
+    // 5        1:24
+    // 6        1:18/1:16
+    // 7        1:10/1:9/1:8
+    
+    // enforce limits
+    if (bias>7) {
+        bias=7;
+    }
+        
+    sendCommand(0b00100001);  // extended mode instruction
+    sendCommand(0b00010000 | bias);  
+    sendCommand(0b00100000); // end of extended mode instruction
+}
+
+// pulse the active low reset line
+void N5110::reset()
+{
+    _rst->write(0);  // reset the LCD
+    _rst->write(1);
+}
+
+// function to initialise SPI peripheral
+void N5110::initSPI()
+{
+    _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
+    _spi->frequency(4000000);  // maximum of screen is 4 MHz
+}
+
+// send a command to the display
+void N5110::sendCommand(unsigned char command)
+{
+    _dc->write(0);  // set DC low for command
+    _sce->write(0); // set CE low to begin frame
+    _spi->write(command);  // send command
+    _dc->write(1);  // turn back to data by default
+    _sce->write(1); // set CE high to end frame (expected for transmission of single byte)
+}
+
+// send data to the display at the current XY address
+// dc is set to 1 (i.e. data) after sending a command and so should
+// be the default mode.
+void N5110::sendData(unsigned char data)
+{
+    _sce->write(0);   // set CE low to begin frame
+    _spi->write(data);
+    _sce->write(1);  // set CE high to end frame (expected for transmission of single byte)
+}
+
+// this function writes 0 to the 504 bytes to clear the RAM
+void N5110::clearRAM()
+{
+    _sce->write(0);  //set CE low to begin frame
+    for(int i = 0; i < WIDTH * HEIGHT; i++) { // 48 x 84 bits = 504 bytes
+        _spi->write(0x00);  // send 0's
+    }
+    _sce->write(1); // set CE high to end frame
+}
+
+// function to set the XY address in RAM for subsequenct data write
+void N5110::setXYAddress(unsigned int const x,
+                         unsigned int const y)
+{
+    if (x<WIDTH && y<HEIGHT) {  // check within range
+        sendCommand(0b00100000);  // basic instruction
+        sendCommand(0b10000000 | x);  // send addresses to display with relevant mask
+        sendCommand(0b01000000 | y);
+    }
+}
+
+// These functions are used to set, clear and get the value of pixels in the display
+// Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x).  The refresh()
+// function must be called after set and clear in order to update the display
+void N5110::setPixel(unsigned int const x,
+                     unsigned int const y,
+                     bool const         state)
+{
+    if (x<WIDTH && y<HEIGHT) {  // check within range
+        // calculate bank and shift 1 to required position in the data byte
+        if(state) buffer[x][y/8] |= (1 << y%8);
+        else      buffer[x][y/8] &= ~(1 << y%8);
+    }
+}
+
+void N5110::clearPixel(unsigned int const x,
+                       unsigned int const y)
+{
+    if (x<WIDTH && y<HEIGHT) {  // check within range
+        // calculate bank and shift 1 to required position (using bit clear)
+        buffer[x][y/8] &= ~(1 << y%8);
+    }
+}
+
+int N5110::getPixel(unsigned int const x,
+                    unsigned int const y) const
+{
+    if (x<WIDTH && y<HEIGHT) {  // check within range
+        // return relevant bank and mask required bit
+
+        int pixel = (int) buffer[x][y/8] & (1 << y%8);
+
+        if (pixel)
+            return 1;
+        else
+            return 0;
+    }
+
+    return 0;
+
+}
+
+// function to refresh the display
+void N5110::refresh()
+{
+    setXYAddress(0,0);  // important to set address back to 0,0 before refreshing display
+    // address auto increments after printing string, so buffer[0][0] will not coincide
+    // with top-left pixel after priting string
+
+    _sce->write(0);  //set CE low to begin frame
+
+    for(int j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
+        for(int i = 0; i < WIDTH; i++) {
+            _spi->write(buffer[i][j]);  // send buffer
+        }
+    }
+    _sce->write(1); // set CE high to end frame
+
+}
+
+// fills the buffer with random bytes.  Can be used to test the display.
+// The rand() function isn't seeded so it probably creates the same pattern everytime
+void N5110::randomiseBuffer()
+{
+    int i,j;
+    for(j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
+        for(i = 0; i < WIDTH; i++) {
+            buffer[i][j] = rand()%256;  // generate random byte
+        }
+    }
+
+}
+
+// function to print 5x7 font
+void N5110::printChar(char const          c,
+                      unsigned int const  x,
+                      unsigned int const  y)
+{
+    if (y<BANKS) {  // check if printing in range of y banks
+
+        for (int i = 0; i < 5 ; i++ ) {
+            int pixel_x = x+i;
+            if (pixel_x > WIDTH-1)  // ensure pixel isn't outside the buffer size (0 - 83)
+                break;
+            buffer[pixel_x][y] = font5x7[(c - 32)*5 + i];
+            // array is offset by 32 relative to ASCII, each character is 5 pixels wide
+        }
+
+    }
+}
+
+// function to print string at specified position
+void N5110::printString(const char         *str,
+                        unsigned int const  x,
+                        unsigned int const  y)
+{
+    if (y<BANKS) {  // check if printing in range of y banks
+
+        int n = 0 ; // counter for number of characters in string
+        // loop through string and print character
+        while(*str) {
+
+            // writes the character bitmap data to the buffer, so that
+            // text and pixels can be displayed at the same time
+            for (int i = 0; i < 5 ; i++ ) {
+                int pixel_x = x+i+n*6;
+                if (pixel_x > WIDTH-1) // ensure pixel isn't outside the buffer size (0 - 83)
+                    break;
+                buffer[pixel_x][y] = font5x7[(*str - 32)*5 + i];
+            }
+            str++;  // go to next character in string
+            n++;    // increment index
+        }
+    }
+}
+
+// function to clear the screen buffer
+void N5110::clear()
+{
+    memset(buffer,0,sizeof(buffer));
+}
+
+// function to plot array on display
+void N5110::plotArray(float const array[])
+{
+    for (int i=0; i<WIDTH; i++) {  // loop through array
+        // elements are normalised from 0.0 to 1.0, so multiply
+        // by 47 to convert to pixel range, and subtract from 47
+        // since top-left is 0,0 in the display geometry
+        setPixel(i,47 - int(array[i]*47.0f),true);
+    }
+
+}
+
+// function to draw circle
+void N5110:: drawCircle(unsigned int const x0,
+                        unsigned int const y0,
+                        unsigned int const radius,
+                        FillType const     fill)
+{
+    // from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
+    int x = radius;
+    int y = 0;
+    int radiusError = 1-x;
+
+    while(x >= y) {
+
+        // if transparent, just draw outline
+        if (fill == FILL_TRANSPARENT) {
+            setPixel( x + x0,  y + y0,true);
+            setPixel(-x + x0,  y + y0,true);
+            setPixel( y + x0,  x + y0,true);
+            setPixel(-y + x0,  x + y0,true);
+            setPixel(-y + x0, -x + y0,true);
+            setPixel( y + x0, -x + y0,true);
+            setPixel( x + x0, -y + y0,true);
+            setPixel(-x + x0, -y + y0,true);
+        } else {  // drawing filled circle, so draw lines between points at same y value
+
+            int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
+
+            drawLine(x+x0,y+y0,-x+x0,y+y0,type);
+            drawLine(y+x0,x+y0,-y+x0,x+y0,type);
+            drawLine(y+x0,-x+y0,-y+x0,-x+y0,type);
+            drawLine(x+x0,-y+y0,-x+x0,-y+y0,type);
+        }
+
+        y++;
+        if (radiusError<0) {
+            radiusError += 2 * y + 1;
+        } else {
+            x--;
+            radiusError += 2 * (y - x) + 1;
+        }
+    }
+
+}
+
+void N5110::drawLine(unsigned int const x0,
+                     unsigned int const y0,
+                     unsigned int const x1,
+                     unsigned int const y1,
+                     unsigned int const type)
+{
+    // Note that the ranges can be negative so we have to turn the input values
+    // into signed integers first
+    int const y_range = static_cast<int>(y1) - static_cast<int>(y0);
+    int const x_range = static_cast<int>(x1) - static_cast<int>(x0);
+
+    // if dotted line, set step to 2, else step is 1
+    unsigned int const step = (type==2) ? 2:1;
+
+    // make sure we loop over the largest range to get the most pixels on the display
+    // for instance, if drawing a vertical line (x_range = 0), we need to loop down the y pixels
+    // or else we'll only end up with 1 pixel in the x column
+    if ( abs(x_range) > abs(y_range) ) {
+
+        // ensure we loop from smallest to largest or else for-loop won't run as expected
+        unsigned int const start = x_range > 0 ? x0:x1;
+        unsigned int const stop =  x_range > 0 ? x1:x0;
+
+        // loop between x pixels
+        for (unsigned int x = start; x<= stop ; x+=step) {
+            // do linear interpolation
+            int const dx = static_cast<int>(x)-static_cast<int>(x0);
+            unsigned int const y = y0 + y_range * dx / x_range;
+
+            // If the line type is '0', this will clear the pixel
+            // If it is '1' or '2', the pixel will be set
+            setPixel(x,y, type);
+        }
+    } else {
+
+        // ensure we loop from smallest to largest or else for-loop won't run as expected
+        unsigned int const start = y_range > 0 ? y0:y1;
+        unsigned int const stop =  y_range > 0 ? y1:y0;
+
+        for (unsigned int y = start; y<= stop ; y+=step) {
+            // do linear interpolation
+            int const dy = static_cast<int>(y)-static_cast<int>(y0);
+            unsigned int const x = x0 + x_range * dy / y_range;
+
+            // If the line type is '0', this will clear the pixel
+            // If it is '1' or '2', the pixel will be set
+            setPixel(x,y, type);
+        }
+    }
+
+}
+
+void N5110::drawRect(unsigned int const x0,
+                     unsigned int const y0,
+                     unsigned int const width,
+                     unsigned int const height,
+                     FillType const     fill)
+{
+    if (fill == FILL_TRANSPARENT) { // transparent, just outline
+        drawLine(x0,y0,x0+(width-1),y0,1);  // top
+        drawLine(x0,y0+(height-1),x0+(width-1),y0+(height-1),1);  // bottom
+        drawLine(x0,y0,x0,y0+(height-1),1);  // left
+        drawLine(x0+(width-1),y0,x0+(width-1),y0+(height-1),1);  // right
+    } else { // filled rectangle
+        int type = (fill==FILL_BLACK) ? 1:0;  // black or white fill
+        for (int y = y0; y<y0+height; y++) {  // loop through rows of rectangle
+            drawLine(x0,y,x0+(width-1),y,type);  // draw line across screen
+        }
+    }
+}
+
+void N5110::drawSprite(int x0,
+                       int y0,
+                       int nrows,
+                       int ncols,
+                       int *sprite)
+{
+    for (int i = 0; i < nrows; i++) {
+        for (int j = 0 ; j < ncols ; j++) {
+
+            int pixel = *((sprite+i*ncols)+j);
+            setPixel(x0+j,y0+i, pixel);
+        }
+    }
+}
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