main.cpp

00001 /*
00002 Initial prototyping to check hardware connections
00003 
00004 Testing the following connections:
00005 
00006 Joystick:
00007 xPot            yPot            button
00008 AnalogIn PTB11, AnalogIn PTB10, PTB9
00009 
00010 Nokia 5110 lcd display: (Handled by library)
00011 VCC    SCE   RST   D/C   MOSI  SCLK  LED
00012 PTE26, PTA0, PTC4, PTD0, PTD2, PTD1, PTC3
00013 
00014 buttonA    buttonB    g_led       buzzer
00015 PTA1       PTB23      PWM PTC11   Undecided between AnalogOut DAC0_OUT or PWM PTC10 (decision will be based on sound quality)
00016 
00017 01/03/16
00018 By Joel W. Webb
00019 Revision 1.0
00020 */
00021 
00022 #include "mbed.h"
00023 #include "N5110.h"
00024 
00025 #define DIRECTION_TOLERANCE 0.05
00026 
00027 // Nokia lcd object
00028 //        VCC    SCE   RST   D/C   MOSI  SCLK  LED 
00029 N5110 lcd(PTE26, PTA0, PTC4, PTD0, PTD2, PTD1, PTC3);
00030 
00031 // Joystick
00032 AnalogIn xPot(PTB11);
00033 AnalogIn yPot(PTB10);
00034 DigitalIn button(PTB9);
00035 
00036 enum DirectionName {
00037     UP,
00038     DOWN,
00039     LEFT,
00040     RIGHT,
00041     CENTRE,
00042     UNKNOWN
00043 };
00044 
00045 // struct for Joystick
00046 typedef struct JoyStick Joystick;
00047 struct JoyStick {
00048     float x;    // current x value
00049     float x0;   // 'centred' x value
00050     float y;    // current y value
00051     float y0;   // 'centred' y value
00052     int button; // button state (assume pull-down used, so 1 = pressed, 0 = unpressed)
00053     DirectionName direction;  // current direction
00054 };
00055 // create struct variable
00056 Joystick joystick;
00057 Ticker pollJoystick; // Ticker interrput for polling the joystick
00058 
00059 // Other inputs/outputs
00060 InterruptIn buttonA(PTA1);
00061 InterruptIn buttonB(PTB23);
00062 PwmOut g_led(PTC11);
00063 DigitalOut r_led(LED1); // Testing led
00064 
00065 //Global Flags defined here
00066 int g_joystick_flag;
00067 int g_buttonA_flag;
00068 int g_buttonB_flag;
00069 
00070 // ISR defined here
00071 void buttonA_isr(){
00072     g_buttonA_flag = 1;    
00073 }
00074 void buttonB_isr(){
00075     g_buttonB_flag = 1;    
00076 }
00077 
00078 // Functions defined here
00079 void initInputs();
00080 void updateJoystick();
00081 void calibrateJoystick();
00082 
00083 int main()
00084 {
00085     initInputs();
00086     pollJoystick.attach(&updateJoystick,1.0/10.0);  // read joystick 10 times per second
00087     
00088     while (true) {
00089         
00090         if (g_buttonA_flag){
00091             g_buttonA_flag = 0;
00092             lcd.clear();
00093             lcd.printString("Button A",0,0);  
00094         }
00095         if (g_buttonB_flag){
00096             g_buttonB_flag = 0;
00097             lcd.clear();
00098             lcd.printString("Button B",0,1);    
00099         }
00100         if (g_joystick_flag){
00101             g_joystick_flag = 0;
00102             lcd.printString("            ",0,2);
00103             if (joystick.direction == 0){ lcd.printString("UP",0,2); }
00104             else if (joystick.direction == 1){ lcd.printString("DOWN",0,2); }
00105             else if (joystick.direction == 2){ lcd.printString("LEFT",0,2); }
00106             else if (joystick.direction == 3){ lcd.printString("RIGHT",0,2); }
00107             else if (joystick.direction == 4){ lcd.printString("CENTRE",0,2); }
00108             else if (joystick.direction == 5){ lcd.printString("UNDEFINED",0,2); }
00109             if (joystick.button){ lcd.printString("Button J",0,3); }
00110         }
00111         
00112         lcd.refresh();
00113         sleep();
00114         
00115     }
00116 }
00117 
00118 
00119 
00120 void initInputs(){
00121     
00122     r_led = 1;
00123     // Initialising power LED
00124     g_led.period(0.001); // Frequency of 1kHz
00125     g_led = 0.25; // Duty cycle of 0.25
00126     
00127     // Setting up Interrupt service routines for input buttons
00128     // Note no pull mode is specified so default pulldown resistors will be used
00129     buttonA.rise(&buttonA_isr);
00130     buttonB.rise(&buttonB_isr);
00131     buttonA.mode(PullDown);
00132     buttonB.mode(PullDown);
00133     
00134     
00135     //Testing LCD display works (splash screen)
00136     lcd.init();
00137     wait(1.0);
00138     lcd.printString("Calibrating",0,0);
00139     lcd.printString("Do not move",0,1);
00140     lcd.printString("Joystick",0,2);
00141     lcd.refresh();
00142     
00143     calibrateJoystick();
00144 
00145     wait(1.0);
00146     lcd.clear();
00147 
00148 }
00149 
00150 // read default positions of the joystick to calibrate later readings
00151 void calibrateJoystick()
00152 {
00153     button.mode(PullDown);
00154     // must not move during calibration
00155     joystick.x0 = xPot;  // initial positions in the range 0.0 to 1.0 (0.5 if centred exactly)
00156     joystick.y0 = yPot;
00157 }
00158 void updateJoystick()
00159 {
00160     // read current joystick values relative to calibrated values (in range -0.5 to 0.5, 0.0 is centred)
00161     joystick.x = xPot - joystick.x0;
00162     joystick.y = yPot - joystick.y0;
00163     // read button state
00164     joystick.button = button;
00165  
00166     // calculate direction depending on x,y values
00167     // tolerance allows a little lee-way in case joystick not exactly in the stated direction
00168     if ( fabs(joystick.y) < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
00169         joystick.direction = CENTRE;
00170     } else if ( joystick.y > DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
00171         joystick.direction = UP;
00172     } else if ( joystick.y < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
00173         joystick.direction = DOWN;
00174     } else if ( joystick.x > DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
00175         joystick.direction = RIGHT;
00176     } else if ( joystick.x < DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
00177         joystick.direction = LEFT;
00178     } else {
00179         joystick.direction = UNKNOWN;
00180     }
00181  
00182     // set flag for printing
00183     g_joystick_flag = 1;
00184 }
00185