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Dependencies:   mbed

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API Documentation at this revision

Comitter:
sjuzyz
Date:
Mon Apr 27 12:01:16 2020 +0000
Commit message:
mid

Changed in this revision

Joystick/Joystick.cpp Show annotated file Show diff for this revision Revisions of this file
Joystick/Joystick.h Show annotated file Show diff for this revision Revisions of this file
N5110/Bitmap.cpp Show annotated file Show diff for this revision Revisions of this file
N5110/Bitmap.h Show annotated file Show diff for this revision Revisions of this file
N5110/N5110.cpp Show annotated file Show diff for this revision Revisions of this file
N5110/N5110.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 9a525a0d1d3f Joystick/Joystick.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Joystick/Joystick.cpp	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,162 @@
+#include "Joystick.h"
+
+Joystick::Joystick(PinName vertPin,PinName horizPin,PinName clickPin)
+{
+    vert = new AnalogIn(vertPin);
+    horiz = new AnalogIn(horizPin);
+    click = new InterruptIn(clickPin);
+}
+
+void Joystick::init()
+{
+    // read centred values of joystick
+    _x0 = horiz->read();
+    _y0 = vert->read();
+
+    // this assumes that the joystick is centred when the init function is called
+    // if perfectly centred, the pots should read 0.5, but this may
+    // not be the case and x0 and y0 will be used to calibrate readings
+
+    // turn on pull-down for button -> this assumes the other side of the button
+    // is connected to +3V3 so we read 1 when pressed and 0 when not pressed
+    click->mode(PullDown);
+    // we therefore need to fire the interrupt on a rising edge
+    click->rise(callback(this,&Joystick::click_isr));
+    // need to use a callback since mbed-os5 - basically tells it to look in this class for the ISR
+    _click_flag = 0;
+
+}
+
+Direction Joystick::get_direction()
+{
+    float angle = get_angle();  // 0 to 360, -1 for centred
+
+    Direction d;
+    // partition 360 into segments and check which segment the angle is in
+    if (angle < 0.0f) {
+        d = CENTRE;   // check for -1.0 angle
+    } else if (angle < 22.5f) {  // then keep going in 45 degree increments
+        d = N;
+    } else if (angle < 67.5f) {
+        d = NE;
+    } else if (angle < 112.5f) {
+        d = E;
+    } else if (angle < 157.5f) {
+        d = SE;
+    } else if (angle < 202.5f) {
+        d = S;
+    } else if (angle < 247.5f) {
+        d = SW;
+    } else if (angle < 292.5f) {
+        d = W;
+    } else if (angle < 337.5f) {
+        d = NW;
+    } else {
+        d = N;
+    }
+
+    return d;
+}
+
+// this method gets the magnitude of the joystick movement
+float Joystick::get_mag()
+{
+    Polar p = get_polar();
+    return p.mag;
+}
+
+// this method gets the angle of joystick movement (0 to 360, 0 North)
+float Joystick::get_angle()
+{
+    Polar p = get_polar();
+    return p.angle;
+}
+
+// get raw joystick coordinate in range -1 to 1
+// Direction (x,y)
+// North     (0,1)
+// East      (1,0)
+// South     (0,-1)
+// West      (-1,0)
+Vector2D Joystick::get_coord()
+{
+    // read() returns value in range 0.0 to 1.0 so is scaled and centre value
+    // substracted to get values in the range -1.0 to 1.0
+    float x = 2.0f*( horiz->read() - _x0 );
+    float y = 2.0f*( vert->read() - _y0 );
+
+    // Note: the x value here is inverted to ensure the positive x is to the
+    // right. This is simply due to how the potentiometer on the joystick
+    // I was using was connected up. It could have been corrected in hardware
+    // by swapping the power supply pins. Instead it is done in software so may
+    // need to be changed depending on your wiring setup
+
+    Vector2D coord = {-x,y};
+    return coord;
+}
+
+// This maps the raw x,y coord onto a circular grid.
+// See:  http://mathproofs.blogspot.co.uk/2005/07/mapping-square-to-circle.html
+Vector2D Joystick::get_mapped_coord()
+{
+    Vector2D coord = get_coord();
+
+    // do the transformation
+    float x = coord.x*sqrt(1.0f-pow(coord.y,2.0f)/2.0f);
+    float y = coord.y*sqrt(1.0f-pow(coord.x,2.0f)/2.0f);
+
+    Vector2D mapped_coord = {x,y};
+    return mapped_coord;
+}
+
+// this function converts the mapped coordinates into polar form
+Polar Joystick::get_polar()
+{
+    // get the mapped coordinate
+    Vector2D coord = get_mapped_coord();
+
+    // at this point, 0 degrees (i.e. x-axis) will be defined to the East.
+    // We want 0 degrees to correspond to North and increase clockwise to 359
+    // like a compass heading, so we need to swap the axis and invert y
+    float x = coord.y;
+    float y = coord.x;
+
+    float mag = sqrt(x*x+y*y);  // pythagoras
+    float angle = RAD2DEG*atan2(y,x);
+    // angle will be in range -180 to 180, so add 360 to negative angles to
+    // move to 0 to 360 range
+    if (angle < 0.0f) {
+        angle+=360.0f;
+    }
+
+    // the noise on the ADC causes the values of x and y to fluctuate slightly
+    // around the centred values. This causes the random angle values to get
+    // calculated when the joystick is centred and untouched. This is also when
+    // the magnitude is very small, so we can check for a small magnitude and then
+    // set the angle to -1. This will inform us when the angle is invalid and the
+    // joystick is centred
+
+    if (mag < TOL) {
+        mag = 0.0f;
+        angle = -1.0f;
+    }
+
+    Polar p = {mag,angle};
+    return p;
+}
+
+bool Joystick::button_pressed()
+{
+    // ISR must have been triggered
+    if (_click_flag) {
+        _click_flag = 0;  // clear flag
+        return true;
+    } else {
+        return false;
+    }
+}
+
+void Joystick::click_isr()
+{
+    _click_flag = 1;
+}
diff -r 000000000000 -r 9a525a0d1d3f Joystick/Joystick.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Joystick/Joystick.h	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,108 @@
+#ifndef JOYSTICK_H
+#define JOYSTICK_H
+
+#include "mbed.h"
+
+// this value can be tuned to alter tolerance of joystick movement
+#define TOL 0.1f
+#define RAD2DEG 57.2957795131f
+
+enum Direction {
+    CENTRE,  // 0
+    N,       // 1
+    NE,      // 2
+    E,       // 3
+    SE,      // 4
+    S,       // 5
+    SW,      // 6
+    W,       // 7
+    NW      // 8
+};
+
+struct Vector2D {
+  float x;
+  float y;  
+};
+
+struct Polar {
+    float mag;
+    float angle;
+};
+
+/** Joystick Class
+@author Dr Craig A. Evans, University of Leeds
+@brief  Library for interfacing with analogue joystick
+
+Example:
+
+@code
+
+#include "mbed.h"
+#include "Joystick.h"
+
+//                  y     x     button
+Joystick joystick(PTB10,PTB11,PTC16);
+
+int main() {
+    
+    joystick.init();
+    
+    while(1) {
+    
+        Vector2D coord = joystick.get_coord();
+        printf("Coord = %f,%f\n",coord.x,coord.y);
+        
+        Vector2D mapped_coord = joystick.get_mapped_coord(); 
+        printf("Mapped coord = %f,%f\n",mapped_coord.x,mapped_coord.y); 
+        
+        float mag = joystick.get_mag();
+        float angle = joystick.get_angle();
+        printf("Mag = %f Angle = %f\n",mag,angle);
+        
+        Direction d = joystick.get_direction();
+        printf("Direction = %i\n",d);
+        
+        if (joystick.button_pressed() ) {
+            printf("Button Pressed\n");  
+        }
+          
+        wait(0.5);
+    }
+    
+    
+}
+
+* @endcode
+*/
+class Joystick
+{
+public:
+    
+    //              y-pot              x-pot            button
+    Joystick(PinName vertPin,PinName horizPin,PinName clickPin);
+    
+    void init();  // needs to be called at start with joystick centred
+    float get_mag();              // polar
+    float get_angle();            // polar
+    Vector2D get_coord();         // cartesian co-ordinates x,y
+    Vector2D get_mapped_coord();  // x,y mapped to circle
+    Direction get_direction();    // N,NE,E,SE etc.
+    Polar get_polar();            // mag and angle in struct form
+    bool button_pressed();        // read button flag set in ISR when button pressed
+    
+private:
+
+    AnalogIn *vert;
+    AnalogIn *horiz;
+    InterruptIn *click;
+    
+    int _click_flag;    // flag set in ISR
+    void click_isr();   // ISR on button press
+       
+    // centred x,y values    
+    float _x0;
+    float _y0;
+    
+};
+
+#endif
\ No newline at end of file
diff -r 000000000000 -r 9a525a0d1d3f N5110/Bitmap.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110/Bitmap.cpp	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,96 @@
+#include "Bitmap.h"
+
+#include <iostream>
+
+#include "N5110.h"
+
+Bitmap::Bitmap(int const               *contents,
+               unsigned int const       height,
+               unsigned int const       width)
+    :
+    _contents(std::vector<int>(height*width)),
+    _height(height),
+    _width(width)
+{
+    // Perform a quick sanity check of the dimensions
+    if (_contents.size() != height * width) {
+        std::cerr << "Contents of bitmap has size " << _contents.size()
+                  << " pixels, but its dimensions were specified as "
+                  << width << " * " << height << " = " << width * height << std::endl;
+    }
+
+    for(unsigned int i = 0; i < height*width; ++i) _contents[i] = contents[i];
+}
+
+/**
+ * @returns the value of the pixel at the given position
+ */
+int Bitmap::get_pixel(unsigned int const row,
+                      unsigned int const column) const
+{
+    // First check that row and column indices are within bounds
+    if(column >= _width || row >= _height)
+    {
+        std::cerr << "The requested pixel with index " << row << "," << column
+                  << "is outside the bitmap dimensions: " << _width << ","
+                  << _height << std::endl;
+    }
+
+    // Now return the pixel value, using row-major indexing
+    return _contents[row * _width + column];
+}
+
+/**
+ * @brief Prints the contents of the bitmap to the terminal
+ */
+void Bitmap::print() const
+{
+    for (unsigned int row = 0; row < _height; ++row)
+    {
+        // Print each element of the row
+        for (unsigned int column = 0; column < _width; ++column)
+        {
+            int pixel = get_pixel(row, column);
+            std::cout << pixel;
+        }
+
+        // And then terminate with a new-line character
+        std::cout << std::endl;
+    }
+}
+
+/**
+ * @brief Renders the contents of the bitmap onto an N5110 screen
+ *
+ * @param[in] lcd The screen to use for rendering
+ * @param[in] x0  The horizontal position in pixels at which to render the bitmap
+ * @param[in] y0  The vertical position in pixels at which to render the bitmap
+ *
+ * @details Note that x0, y0 gives the location of the top-left of the bitmap on
+ *          the screen.
+ *          This function only updates the buffer on the screen.  You still need
+ *          to refresh the screen in order to actually see the bitmap.
+ */
+void Bitmap::render(N5110 &lcd,
+                    unsigned int const x0,
+                    unsigned int const y0) const
+{
+    // Loop through each row of the bitmap image
+    for (unsigned int bitmap_row = 0; bitmap_row < _height; ++bitmap_row)
+    {
+        // Row index on the screen for rendering the row of pixels
+        unsigned int screen_row = y0 + bitmap_row;
+                
+        // Render each pixel in the row
+        for (unsigned int bitmap_col = 0; bitmap_col < _width; ++bitmap_col)
+        {
+            // Column index on the screen for rendering this pixel
+            int screen_col = x0 + bitmap_col;
+
+            // Find the required value of the pixel at the given location within
+            // the bitmap data and then write it to the LCD screen
+            int pixel = get_pixel(bitmap_row, bitmap_col);
+            lcd.setPixel(screen_col, screen_row, pixel);
+        }
+    }
+}
\ No newline at end of file
diff -r 000000000000 -r 9a525a0d1d3f N5110/Bitmap.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110/Bitmap.h	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,65 @@
+#ifndef BITMAP_H
+#define BITMAP_H
+
+#include <vector>
+
+// Forward declarations
+class N5110;
+
+/**
+ * @brief  A black & white bitmap that can be rendered on an N5110 screen
+ * @author Alex Valavanis <a.valavanis@leeds.ac.uk>
+ * 
+ * @code
+  // First declare the pixel map data using '1' for black,
+  // or '0' for white pixels
+  static int sprite_data[] = {
+    0,0,1,0,0,
+    0,1,1,1,0,
+    0,0,1,0,0,
+    0,1,1,1,0,
+    1,1,1,1,1,
+    1,1,1,1,1,
+    1,1,0,1,1,
+    1,1,0,1,1
+  };
+
+  // Instantiate the Bitmap object using the data above
+  Bitmap sprite(sprite_data, 8, 5); // Specify rows and columns in sprite
+  
+  // We can render the bitmap wherever we want on the screen
+  sprite.render(lcd, 20, 6); // x and y locations for rendering
+  sprite.render(lcd, 30, 10);
+  
+  // We can also print its values to the terminal
+  sprite.print();
+ * @endcode
+ */
+class Bitmap
+{
+private:
+    /**
+     * @brief The contents of the drawing, with pixels stored in row-major order
+     * @details '1' represents a black pixel; '0' represents white
+     */
+    std::vector<int> _contents;
+    
+    unsigned int _height; ///< The height of the drawing in pixels
+    unsigned int _width;  ///< The width of the drawing in pixels
+    
+public:
+    Bitmap(int const          *contents,
+           unsigned int const  height,
+           unsigned int const  width);
+
+    int get_pixel(unsigned int const row,
+                  unsigned int const column) const;
+
+    void print() const;
+
+    void render(N5110 &lcd,
+                unsigned int const x0,
+                unsigned int const y0) const;
+};
+
+#endif // BITMAP_H
\ No newline at end of file
diff -r 000000000000 -r 9a525a0d1d3f N5110/N5110.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110/N5110.cpp	Mon Apr 27 12:01:16 2020 +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);
+        }
+    }
+}
\ No newline at end of file
diff -r 000000000000 -r 9a525a0d1d3f N5110/N5110.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110/N5110.h	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,534 @@
+#ifndef N5110_H
+#define N5110_H
+
+#include "mbed.h"
+
+// number of pixels on display
+#define WIDTH 84
+#define HEIGHT 48
+#define BANKS 6
+
+/// Fill types for 2D shapes
+enum FillType {
+    FILL_TRANSPARENT, ///< Transparent with outline
+    FILL_BLACK,       ///< Filled black
+    FILL_WHITE,       ///< Filled white (no outline)
+};
+
+/** N5110 Class
+@brief Library for interfacing with Nokia 5110 LCD display (https://www.sparkfun.com/products/10168) using the hardware SPI on the mbed.
+@brief The display is powered from a GPIO pin meaning it can be controlled via software.  The LED backlight is also software-controllable (via PWM pin).
+@brief Can print characters and strings to the display using the included 5x7 font.
+@brief The library also implements a screen buffer so that individual pixels on the display (84 x 48) can be set, cleared and read.
+@brief The library can print primitive shapes (lines, circles, rectangles)
+@brief Acknowledgements to Chris Yan's Nokia_5110 Library.
+
+@brief Revision 1.3
+
+@author Craig A. Evans
+@date   7th February 2017
+
+@code
+
+#include "mbed.h"
+#include "N5110.h"
+
+//      rows,cols
+int sprite[8][5] =   {
+    { 0,0,1,0,0 },
+    { 0,1,1,1,0 },
+    { 0,0,1,0,0 },
+    { 0,1,1,1,0 },
+    { 1,1,1,1,1 },
+    { 1,1,1,1,1 },
+    { 1,1,0,1,1 },
+    { 1,1,0,1,1 },
+};
+
+//    VCC,SCE,RST,D/C,MOSI,SCLK,LED
+//N5110 lcd(p7,p8,p9,p10,p11,p13,p21);  // LPC1768 - pwr from GPIO
+N5110 lcd(p8,p9,p10,p11,p13,p21);  // LPC1768 - powered from +3V3 - JP1 in 2/3 position
+//N5110 lcd(PTC9,PTC0,PTC7,PTD2,PTD1,PTC11);  // K64F - pwr from 3V3
+
+int main()
+{
+    // first need to initialise display
+    lcd.init();
+    
+    // change set contrast in range 0.0 to 1.0
+    // 0.4 appears to be a good starting point
+    lcd.setContrast(0.4);
+
+    while(1) {
+
+        // these are default settings so not strictly needed
+        lcd.normalMode();      // normal colour mode
+        lcd.setBrightness(0.5); // put LED backlight on 50%
+
+        lcd.clear();
+        // x origin, y origin, rows, cols, sprite
+        lcd.drawSprite(20,6,8,5,(int *)sprite);
+        lcd.refresh();
+        wait(5.0);
+
+        lcd.clear(); // clear buffer at start of every loop
+        // can directly print strings at specified co-ordinates (must be less than 84 pixels to fit on display)
+        lcd.printString("Hello, World!",0,0);
+
+        char buffer[14];  // each character is 6 pixels wide, screen is 84 pixels (84/6 = 14)
+        // so can display a string of a maximum 14 characters in length
+        // or create formatted strings - ensure they aren't more than 14 characters long
+        int temperature = 27;
+        int length = sprintf(buffer,"T = %2d C",temperature); // print formatted data to buffer
+        // it is important the format specifier ensures the length will fit in the buffer
+        if (length <= 14)  // if string will fit on display (assuming printing at x=0)
+            lcd.printString(buffer,0,1);           // display on screen
+
+        float pressure = 1012.3;  // same idea with floats
+        length = sprintf(buffer,"P = %.2f mb",pressure);
+        if (length <= 14)
+            lcd.printString(buffer,0,2);
+
+        // can also print individual characters at specified place
+        lcd.printChar('X',5,3);
+
+        // draw a line across the display at y = 40 pixels (origin top-left)
+        for (int i = 0; i < WIDTH; i++) {
+            lcd.setPixel(i,40,true);
+        }
+        // need to refresh display after setting pixels or writing strings
+        lcd.refresh();
+        wait(5.0);
+
+        // can check status of pixel using getPixel(x,y);
+        lcd.clear();  // clear buffer
+        lcd.setPixel(2,2,true);  // set random pixel in buffer
+        lcd.refresh();
+        wait(1.0);
+
+        int pixel_to_test = lcd.getPixel(2,2);
+
+        if ( pixel_to_test ) {
+            lcd.printString("2,2 is set",0,4);
+        }
+
+        // this one shouldn't be set
+        lcd.setPixel(3,3,false);  // clear random pixel in buffer
+        lcd.refresh();
+        pixel_to_test = lcd.getPixel(3,3);
+
+        if ( pixel_to_test == 0 ) {
+            lcd.printString("3,3 is clear",0,5);
+        }
+
+        lcd.refresh();
+        wait(4.0);
+
+        lcd.clear();            // clear buffer
+        lcd.inverseMode();      // invert colours
+        lcd.setBrightness(1.0); // put LED backlight on full
+
+        float array[84];
+
+        for (int i = 0; i < 84; i++) {
+            array[i] = 0.5 + 0.5*sin(i*2*3.14/84);
+        }
+
+        // can also plot graphs - 84 elements only
+        // values must be in range 0.0 - 1.0
+        lcd.plotArray(array);
+        lcd.refresh();
+        wait(5.0);
+
+        lcd.clear();
+        lcd.normalMode();      // normal colour mode back
+        lcd.setBrightness(0.5); // put LED backlight on 50%
+
+        // example of drawing lines
+        for (int x = 0; x < WIDTH ; x+=10) {
+            // x0,y0,x1,y1,type 0-white,1-black,2-dotted
+            lcd.drawLine(0,0,x,HEIGHT,2);
+        }
+        lcd.refresh();  // refresh after drawing shapes
+        wait(5.0);
+
+
+        lcd.clear();
+        // example of how to draw circles
+        lcd.drawCircle(WIDTH/2,HEIGHT/2,20,FILL_BLACK);  // x,y,radius,black fill
+        lcd.drawCircle(WIDTH/2,HEIGHT/2,10,FILL_WHITE);  // x,y,radius,white fill
+        lcd.drawCircle(WIDTH/2,HEIGHT/2,30,FILL_TRANSPARENT);  // x,y,radius,transparent with outline
+        lcd.refresh();  // refresh after drawing shapes
+        wait(5.0);
+
+        lcd.clear();
+        // example of how to draw rectangles
+        //          origin x,y,width,height,type
+        lcd.drawRect(10,10,50,30,FILL_BLACK);  // filled black rectangle
+        lcd.drawRect(15,15,20,10,FILL_WHITE);  // filled white rectange (no outline)
+        lcd.drawRect(2,2,70,40,FILL_TRANSPARENT);    // transparent, just outline
+        lcd.refresh();  // refresh after drawing shapes
+        wait(5.0);
+
+    }
+}
+
+
+@endcode
+*/
+class N5110
+{
+private:
+// objects
+    SPI         *_spi;
+    PwmOut      *_led;
+    DigitalOut  *_pwr;
+    DigitalOut  *_sce;
+    DigitalOut  *_rst;
+    DigitalOut  *_dc;
+
+// variables
+    unsigned char buffer[84][6];  // screen buffer - the 6 is for the banks - each one is 8 bits;
+
+public:
+    /** Create a N5110 object connected to the specified pins
+    *
+    * @param pwr  Pin connected to Vcc on the LCD display (pin 1)
+    * @param sce  Pin connected to chip enable (pin 3)
+    * @param rst  Pin connected to reset (pin 4)
+    * @param dc   Pin connected to data/command select (pin 5)
+    * @param mosi Pin connected to data input (MOSI) (pin 6)
+    * @param sclk Pin connected to serial clock (SCLK) (pin 7)
+    * @param led  Pin connected to LED backlight (must be PWM) (pin 8)
+    *
+    */
+    N5110(PinName const pwrPin,
+          PinName const scePin,
+          PinName const rstPin,
+          PinName const dcPin,
+          PinName const mosiPin,
+          PinName const sclkPin,
+          PinName const ledPin);
+
+    /** Create a N5110 object connected to the specified pins (Vcc to +3V3)
+    *
+    * @param sce  Pin connected to chip enable (pin 3)
+    * @param rst  Pin connected to reset (pin 4)
+    * @param dc   Pin connected to data/command select (pin 5)
+    * @param mosi Pin connected to data input (MOSI) (pin 6)
+    * @param sclk Pin connected to serial clock (SCLK) (pin 7)
+    * @param led  Pin connected to LED backlight (must be PWM) (pin 8)
+    *
+    */
+    N5110(PinName const scePin,
+          PinName const rstPin,
+          PinName const dcPin,
+          PinName const mosiPin,
+          PinName const sclkPin,
+          PinName const ledPin);
+
+    /**
+     * Free allocated memory when object goes out of scope
+     */
+    ~N5110();
+
+    /** Initialise display
+    *
+    *   Powers up the display and turns on backlight (50% brightness default).
+    *   Sets the display up in horizontal addressing mode and with normal video mode.
+    */
+    void init();
+
+    /** Turn off
+    *
+    *   Powers down the display and turns of the backlight.
+    *   Needs to be reinitialised before being re-used.
+    */
+    void turnOff();
+
+    /** Clear
+    *
+    *   Clears the screen buffer.
+    */
+    void clear();
+
+    /** Set screen constrast
+    *   @param constrast - float in range 0.0 to 1.0 (0.40 to 0.60 is usually a good value)
+    */
+    void setContrast(float contrast);
+    
+    /** Turn on normal video mode (default)
+    *  Black on white
+    */
+    void normalMode();
+
+    /** Turn on inverse video mode (default)
+    *  White on black
+    */
+    void inverseMode();
+
+    /** Set Brightness
+    *
+    *   Sets brightness of LED backlight.
+    *   @param brightness - float in range 0.0 to 1.0
+    */
+    void setBrightness(float const brightness);
+
+    /** Print String
+    *
+    *   Prints a string of characters to the screen buffer. String is cut-off after the 83rd pixel.
+    *   @param x - the column number (0 to 83)
+    *   @param y - the row number (0 to 5) - the display is split into 6 banks - each bank can be considered a row
+    */
+    void printString(char const         *str,
+                     unsigned int const  x,
+                     unsigned int const  y);
+
+    /** Print Character
+    *
+    *   Sends a character to the screen buffer.  Printed at the specified location. Character is cut-off after the 83rd pixel.
+    *   @param  c - the character to print. Can print ASCII as so printChar('C').
+    *   @param x - the column number (0 to 83)
+    *   @param y - the row number (0 to 5) - the display is split into 6 banks - each bank can be considered a row
+    */
+    void printChar(char const         c,
+                   unsigned int const x,
+                   unsigned int const y);
+
+    /**
+    * @brief Set a Pixel
+    *
+    * @param x     The x co-ordinate of the pixel (0 to 83)
+    * @param y     The y co-ordinate of the pixel (0 to 47)
+    * @param state The state of the pixel [true=black (default), false=white]
+    *
+    * @details This function sets the state of a pixel in the screen buffer.
+    *          The third parameter can be omitted,
+    */
+    void setPixel(unsigned int const x,
+                  unsigned int const y,
+                  bool const         state = true);
+
+    /**
+    *  @brief Clear a Pixel
+    *
+    *   @param  x - the x co-ordinate of the pixel (0 to 83)
+    *   @param  y - the y co-ordinate of the pixel (0 to 47)
+    *
+    *   @details This function clears pixel in the screen buffer
+    *
+    *   @deprecated Use setPixel(x, y, false) instead
+    */
+    void clearPixel(unsigned int const x,
+                    unsigned int const y)
+    __attribute__((deprecated("Use setPixel(x,y,false) instead")));
+
+    /** Get a Pixel
+    *
+    *   This function gets the status of a pixel in the screen buffer.
+    *   @param  x - the x co-ordinate of the pixel (0 to 83)
+    *   @param  y - the y co-ordinate of the pixel (0 to 47)
+    *   @returns
+    *       0           - pixel is clear
+    *       1    - pixel is set
+    */
+    int getPixel(unsigned int const x,
+                 unsigned int const y) const;
+
+    /** Refresh display
+    *
+    *   This functions sends the screen buffer to the display.
+    */
+    void refresh();
+
+    /** Randomise buffer
+    *
+    *   This function fills the buffer with random data.  Can be used to test the display.
+    *   A call to refresh() must be made to update the display to reflect the change in pixels.
+    *   The seed is not set and so the generated pattern will probably be the same each time.
+    *   TODO: Randomise the seed - maybe using the noise on the AnalogIn pins.
+    */
+    void randomiseBuffer();
+
+    /** Plot Array
+    *
+    *   This function plots a one-dimensional array in the buffer.
+    *   @param array[] - y values of the plot. Values should be normalised in the range 0.0 to 1.0. First 84 plotted.
+    */
+    void plotArray(float const array[]);
+
+    /** Draw Circle
+    *
+    *   This function draws a circle at the specified origin with specified radius in the screen buffer
+    *   Uses the midpoint circle algorithm.
+    *   @see http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
+    *   @param  x0     - x-coordinate of centre
+    *   @param  y0     - y-coordinate of centre
+    *   @param  radius - radius of circle in pixels
+    *   @param  fill   - fill-type for the shape
+    */
+    void drawCircle(unsigned int const x0,
+                    unsigned int const y0,
+                    unsigned int const radius,
+                    FillType const     fill);
+
+    /** Draw Line
+    *
+    *   This function draws a line between the specified points using linear interpolation.
+    *   @param  x0 - x-coordinate of first point
+    *   @param  y0 - y-coordinate of first point
+    *   @param  x1 - x-coordinate of last point
+    *   @param  y1 - y-coordinate of last point
+    *   @param  type - 0 white,1 black,2 dotted
+    */
+    void drawLine(unsigned int const x0,
+                  unsigned int const y0,
+                  unsigned int const x1,
+                  unsigned int const y1,
+                  unsigned int const type);
+
+    /** Draw Rectangle
+    *
+    *   This function draws a rectangle.
+    *   @param  x0 - x-coordinate of origin (top-left)
+    *   @param  y0 - y-coordinate of origin (top-left)
+    *   @param  width - width of rectangle
+    *   @param  height - height of rectangle
+    *   @param  fill   - fill-type for the shape
+    */
+    void drawRect(unsigned int const x0,
+                  unsigned int const y0,
+                  unsigned int const width,
+                  unsigned int const height,
+                  FillType const     fill);
+
+    /** Draw Sprite
+    *
+    *   This function draws a sprite as defined in a 2D array
+    *   @param  x0 - x-coordinate of origin (top-left)
+    *   @param  y0 - y-coordinate of origin (top-left)
+    *   @param  nrows - number of rows in sprite
+    *   @param  ncols - number of columns in sprite
+    *   @param  sprite - 2D array representing the sprite
+    */
+    void drawSprite(int x0,
+                    int y0,
+                    int nrows,
+                    int ncols,
+                    int *sprite);
+
+
+private:
+// methods
+    void setXYAddress(unsigned int const x,
+                      unsigned int const y);
+    void initSPI();
+    void turnOn();
+    void reset();
+    void clearRAM();
+    void sendCommand(unsigned char command);
+    void sendData(unsigned char data);
+    void setTempCoefficient(char tc);  // 0 to 3
+    void setBias(char bias);  // 0 to 7
+};
+
+const unsigned char font5x7[480] = {
+    0x00, 0x00, 0x00, 0x00, 0x00,// (space)
+    0x00, 0x00, 0x5F, 0x00, 0x00,// !
+    0x00, 0x07, 0x00, 0x07, 0x00,// "
+    0x14, 0x7F, 0x14, 0x7F, 0x14,// #
+    0x24, 0x2A, 0x7F, 0x2A, 0x12,// $
+    0x23, 0x13, 0x08, 0x64, 0x62,// %
+    0x36, 0x49, 0x55, 0x22, 0x50,// &
+    0x00, 0x05, 0x03, 0x00, 0x00,// '
+    0x00, 0x1C, 0x22, 0x41, 0x00,// (
+    0x00, 0x41, 0x22, 0x1C, 0x00,// )
+    0x08, 0x2A, 0x1C, 0x2A, 0x08,// *
+    0x08, 0x08, 0x3E, 0x08, 0x08,// +
+    0x00, 0x50, 0x30, 0x00, 0x00,// ,
+    0x08, 0x08, 0x08, 0x08, 0x08,// -
+    0x00, 0x60, 0x60, 0x00, 0x00,// .
+    0x20, 0x10, 0x08, 0x04, 0x02,// /
+    0x3E, 0x51, 0x49, 0x45, 0x3E,// 0
+    0x00, 0x42, 0x7F, 0x40, 0x00,// 1
+    0x42, 0x61, 0x51, 0x49, 0x46,// 2
+    0x21, 0x41, 0x45, 0x4B, 0x31,// 3
+    0x18, 0x14, 0x12, 0x7F, 0x10,// 4
+    0x27, 0x45, 0x45, 0x45, 0x39,// 5
+    0x3C, 0x4A, 0x49, 0x49, 0x30,// 6
+    0x01, 0x71, 0x09, 0x05, 0x03,// 7
+    0x36, 0x49, 0x49, 0x49, 0x36,// 8
+    0x06, 0x49, 0x49, 0x29, 0x1E,// 9
+    0x00, 0x36, 0x36, 0x00, 0x00,// :
+    0x00, 0x56, 0x36, 0x00, 0x00,// ;
+    0x00, 0x08, 0x14, 0x22, 0x41,// <
+    0x14, 0x14, 0x14, 0x14, 0x14,// =
+    0x41, 0x22, 0x14, 0x08, 0x00,// >
+    0x02, 0x01, 0x51, 0x09, 0x06,// ?
+    0x32, 0x49, 0x79, 0x41, 0x3E,// @
+    0x7E, 0x11, 0x11, 0x11, 0x7E,// A
+    0x7F, 0x49, 0x49, 0x49, 0x36,// B
+    0x3E, 0x41, 0x41, 0x41, 0x22,// C
+    0x7F, 0x41, 0x41, 0x22, 0x1C,// D
+    0x7F, 0x49, 0x49, 0x49, 0x41,// E
+    0x7F, 0x09, 0x09, 0x01, 0x01,// F
+    0x3E, 0x41, 0x41, 0x51, 0x32,// G
+    0x7F, 0x08, 0x08, 0x08, 0x7F,// H
+    0x00, 0x41, 0x7F, 0x41, 0x00,// I
+    0x20, 0x40, 0x41, 0x3F, 0x01,// J
+    0x7F, 0x08, 0x14, 0x22, 0x41,// K
+    0x7F, 0x40, 0x40, 0x40, 0x40,// L
+    0x7F, 0x02, 0x04, 0x02, 0x7F,// M
+    0x7F, 0x04, 0x08, 0x10, 0x7F,// N
+    0x3E, 0x41, 0x41, 0x41, 0x3E,// O
+    0x7F, 0x09, 0x09, 0x09, 0x06,// P
+    0x3E, 0x41, 0x51, 0x21, 0x5E,// Q
+    0x7F, 0x09, 0x19, 0x29, 0x46,// R
+    0x46, 0x49, 0x49, 0x49, 0x31,// S
+    0x01, 0x01, 0x7F, 0x01, 0x01,// T
+    0x3F, 0x40, 0x40, 0x40, 0x3F,// U
+    0x1F, 0x20, 0x40, 0x20, 0x1F,// V
+    0x7F, 0x20, 0x18, 0x20, 0x7F,// W
+    0x63, 0x14, 0x08, 0x14, 0x63,// X
+    0x03, 0x04, 0x78, 0x04, 0x03,// Y
+    0x61, 0x51, 0x49, 0x45, 0x43,// Z
+    0x00, 0x00, 0x7F, 0x41, 0x41,// [
+    0x02, 0x04, 0x08, 0x10, 0x20,// "\"
+    0x41, 0x41, 0x7F, 0x00, 0x00,// ]
+    0x04, 0x02, 0x01, 0x02, 0x04,// ^
+    0x40, 0x40, 0x40, 0x40, 0x40,// _
+    0x00, 0x01, 0x02, 0x04, 0x00,// `
+    0x20, 0x54, 0x54, 0x54, 0x78,// a
+    0x7F, 0x48, 0x44, 0x44, 0x38,// b
+    0x38, 0x44, 0x44, 0x44, 0x20,// c
+    0x38, 0x44, 0x44, 0x48, 0x7F,// d
+    0x38, 0x54, 0x54, 0x54, 0x18,// e
+    0x08, 0x7E, 0x09, 0x01, 0x02,// f
+    0x08, 0x14, 0x54, 0x54, 0x3C,// g
+    0x7F, 0x08, 0x04, 0x04, 0x78,// h
+    0x00, 0x44, 0x7D, 0x40, 0x00,// i
+    0x20, 0x40, 0x44, 0x3D, 0x00,// j
+    0x00, 0x7F, 0x10, 0x28, 0x44,// k
+    0x00, 0x41, 0x7F, 0x40, 0x00,// l
+    0x7C, 0x04, 0x18, 0x04, 0x78,// m
+    0x7C, 0x08, 0x04, 0x04, 0x78,// n
+    0x38, 0x44, 0x44, 0x44, 0x38,// o
+    0x7C, 0x14, 0x14, 0x14, 0x08,// p
+    0x08, 0x14, 0x14, 0x18, 0x7C,// q
+    0x7C, 0x08, 0x04, 0x04, 0x08,// r
+    0x48, 0x54, 0x54, 0x54, 0x20,// s
+    0x04, 0x3F, 0x44, 0x40, 0x20,// t
+    0x3C, 0x40, 0x40, 0x20, 0x7C,// u
+    0x1C, 0x20, 0x40, 0x20, 0x1C,// v
+    0x3C, 0x40, 0x30, 0x40, 0x3C,// w
+    0x44, 0x28, 0x10, 0x28, 0x44,// x
+    0x0C, 0x50, 0x50, 0x50, 0x3C,// y
+    0x44, 0x64, 0x54, 0x4C, 0x44,// z
+    0x00, 0x08, 0x36, 0x41, 0x00,// {
+    0x00, 0x00, 0x7F, 0x00, 0x00,// |
+    0x00, 0x41, 0x36, 0x08, 0x00,// }
+    0x08, 0x08, 0x2A, 0x1C, 0x08,// ->
+    0x08, 0x1C, 0x2A, 0x08, 0x08 // <-
+};
+
+#endif
\ No newline at end of file
diff -r 000000000000 -r 9a525a0d1d3f main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,61 @@
+#include "mbed.h"
+#include "N5110.h"
+
+N5110 lcd(PTC9,PTC0,PTC7,PTD2,PTD1,PTC11); 
+
+InterruptIn buttonL(PTB18);
+InterruptIn buttonR(PTB3);
+
+// g_ prefix makes it easier to distinguish it as global
+volatile int g_buttonL_flag = 0;
+volatile int g_buttonR_flag = 0;
+// Button L&R interrupt service routine
+void buttonL_isr();
+void buttonR_isr();
+
+int main() {
+
+   lcd.init();
+
+   // Button L&R is connected between the pin and 3.3 V, we therefore need to turn on the internal pull-down resister
+    buttonL.mode(PullDown);
+    buttonR.mode(PullDown);
+    // It will return 0 by default and a 1 when pressed i.e. cause a rising edge
+    buttonL.rise(&buttonL_isr);
+    buttonR.rise(&buttonR_isr);
+    
+    int p=20, q=3;      //位置
+    int a=2, b=1;       //步长
+    
+   while(1) {
+       
+       lcd.clear();
+       lcd.printString("Hello!",p,q);
+       
+       if (g_buttonL_flag) {
+            p=p-a;
+            q=q-b;
+            g_buttonL_flag = 0;  // if it has, clear the flag
+        }
+        
+        if (g_buttonR_flag) {
+            p=p+a;
+            q=q+b;
+            g_buttonR_flag = 0;  // if it has, clear the flag
+        }
+        
+       lcd.refresh();         
+       wait(0.1);
+   }
+   
+}
+
+void buttonL_isr()
+{
+    g_buttonL_flag = 1;   // set flag in ISR
+}
+
+void buttonR_isr()
+{
+    g_buttonR_flag = 1;   // set flag in ISR
+}
\ No newline at end of file
diff -r 000000000000 -r 9a525a0d1d3f mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Mon Apr 27 12:01:16 2020 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/176b8275d35d
\ No newline at end of file