main.cpp

00001 /**
00002 @file main.cpp
00003 @brief Radar/Distance Measurement program implementation
00004 @author Karina Sodipo
00005 @date   May 2015
00006 */
00007 
00008 #include "mbed.h"
00009 #include "N5110.h"
00010 #include "SRF02.h"
00011 #include "PowerControl/PowerControl.h"
00012 #include "PowerControl/EthernetPowerControl.h"
00013 
00014 /**
00015 @see - mbed CookBook (Power Management)
00016 */
00017 
00018 /// function to power down the USB interface
00019 #define USR_POWERDOWN    (0x104)
00020 int semihost_powerdown() {
00021     uint32_t arg;
00022     return __semihost(USR_POWERDOWN, &arg);
00023 }
00024 
00025 
00026 /**  
00027 @namespace lcd
00028 @brief LCD screen display with VCC,SCE,RST,D/C,MOSI,SCLK,LED pins
00029 */
00030 N5110 lcd(p7,p8,p9,p10,p11,p13,p26); // 
00031 
00032 /**  
00033 @namespace sensor
00034 @brief SRF02 ultrasonic distance sensor
00035 */
00036 SRF02 sensor(p28,p27);
00037 
00038 /**  
00039 @namespace leds
00040 @brief the on-board mbed LEDs in a BusOut class
00041 */
00042 BusOut leds(LED4,LED3,LED2,LED1);
00043 
00044 /**  
00045 @namespace led
00046 @brief LED proximity indicator
00047 */
00048 PwmOut led(p24);
00049 
00050 /**
00051 @namespace screenInvert
00052 @brief button to switch from black-on-white to white-on-black
00053 */
00054 InterruptIn screenInvert(p16);
00055 
00056 /**  
00057 @namespace unitSW
00058 @brief button to switch from cm to inches
00059 */
00060 InterruptIn unitSW(p17);
00061 
00062 /**  
00063 @namespace radarDist
00064 @brief slide switch toggling radar and distance displays
00065 */
00066 InterruptIn radarDist(p18);
00067 
00068 /**  
00069 @namespace POT
00070 @brief potentiometer to change backlight brightness on LCD screen
00071 */
00072 AnalogIn POT(p20);
00073 
00074 /**  
00075 @namespace buzzer
00076 @brief Piezo buzzer for audio alerts (distance below 50cm / 20inch threshold AND countdown to sensor update)
00077 */
00078 PwmOut buzzer(p21);
00079 
00080 
00081 
00082 /// function to display the checkerboard pattern
00083 void checkerboard();
00084 
00085 /// function for LED and Piezo alerts in CM
00086 void proximityCm();
00087 
00088 /// function for LED and Piezo alerts in INCHES
00089 void proximityIn();
00090 
00091 /// function to define states of screenInvert button
00092 void initDisplay();
00093 
00094 /// function to define states of unitsSW button
00095 void initMeasureIn();
00096 
00097 /// function for potentiometer to change screen brightness
00098 void brightness();
00099 
00100 /// function to display readings/radar in black-on-white mode
00101 void normal();
00102 
00103 /// function to display readings/radar in white-on-black mode
00104 void invert();
00105 
00106 /// function to measure distance in cm
00107 void centimetre();
00108 
00109 /// function to measure distance in inches
00110 void inches();
00111 
00112 /// function for radar display
00113 void radar();
00114 
00115 
00116 
00117 /// buffer to store data sent to the screen
00118 char buffer[14];
00119 
00120 /// Change units to measure distance in, modified in units() ISR
00121 int unit = 0; /*!< 'unit' toggled in units() ISR */
00122 
00123 /// ISR for toggling between CM and INCH readings
00124 void units() {
00125     
00126     unit++;
00127     if (unit > 1) {  // check whether unit modes stays within bounds
00128         unit = 0;
00129     }
00130     
00131 }
00132 
00133 
00134 
00135 /// pixel display style, modified in pixels() ISR
00136 int pixel = 0; /*!< 'pixel' set in pixels() ISR */
00137 
00138 /// ISR for toggling between black-on-white and white-on-black display
00139 void pixels() {
00140     
00141     pixel++;
00142     if (pixel > 1) {  // check whether display modes stays within bounds
00143         pixel = 0;
00144     }
00145 }
00146 
00147 
00148 
00149 int main () {
00150        
00151        /// Power down Ethernet interface to save ~ 175mW
00152        PHY_PowerDown();
00153        
00154        /// Power down magic USB interface chip to save ~ 150mW
00155        int result = semihost_powerdown();
00156        
00157        /// Disable clock on unused peripherals
00158        Peripheral_PowerDown(0x2000); /// CAN controller 1
00159        Peripheral_PowerDown(0x4000); /// CAN controller 2
00160        
00161        /// initialize the screen
00162        lcd.init();
00163        
00164        /// call pixels() on rising edge when button pressed
00165        screenInvert.mode(PullUp);
00166        screenInvert.rise(&pixels);
00167        
00168        /// call units() on rising edge when button pressed
00169        unitSW.mode(PullUp);
00170        unitSW.rise(&units);
00171        
00172        /*
00173        /// switch to radar display
00174        radarDist.rise(&radar);
00175        /// switch to distance reader in cm
00176        radarDist.fall(&centimetre);
00177        */
00178        
00179        /// Device welcome messages - print strings of characters at defined coordinates
00180        lcd.printString("Radar/Distance",0,1);
00181        lcd.printString("Measuring",15,3);
00182        lcd.printString("tool",30,5);
00183        wait(2); /// hold message for 2 secs
00184        lcd.refresh(); /// clear screen
00185        
00186        lcd.printString("A project",15,1);
00187        lcd.printString("by",35,3);
00188        lcd.printString("Karina Sodipo",3,5);
00189        wait(2);
00190        lcd.refresh();
00191        
00192        lcd.printString("University",10,1);
00193        lcd.printString("of Leeds",15,3);
00194        lcd.printString("ELEC2645",15,5);
00195        wait(2);
00196        lcd.refresh();
00197        
00198        /// display a checkerboard pattern to illustrate transition from start-up to main device functionality
00199        checkerboard();
00200        wait(2);
00201        lcd.clear(); /// clear the buffer
00202        lcd.refresh();
00203        
00204        while(1) { /// loop infinitely
00205             
00206             brightness();
00207             
00208             initMeasureIn();
00209             
00210             initDisplay();
00211             
00212     }
00213 
00214 }
00215 
00216 
00217 
00218 /**
00219 @see - University of Leeds ELEC1620 Digital Electronics & Microcontrollers lecture slides
00220 */
00221 /// function to display the checkerboard pattern
00222 void checkerboard() {
00223     for (int i = 0; i < 84; i+=2) {
00224         for (int j = 0; j < 48; j+=2) {
00225             lcd.setPixel(i,j);
00226         }
00227     }
00228     lcd.refresh();
00229 }
00230 
00231 
00232 
00233 /// function to indicate object proximity on LED and buzzer in CM
00234 /// Buzzer counts down to sensor update
00235 /// LED and buzzer indicate when proximity is < 50 cm
00236 void proximityCm() {
00237     
00238     int distance = sensor.getDistanceCm();
00239     
00240     /// beep at max volume (dutycycle = 50%) for 3 sec
00241     if (distance < 50) {
00242         led = 1;
00243         buzzer = 0.5;
00244         wait(0.5);
00245         led = 0;
00246         buzzer = 0;
00247         wait(0.25);
00248         led = 1;
00249         buzzer = 0.5;
00250         wait(0.5);
00251         led = 0;
00252         buzzer = 0;
00253         wait(0.25);
00254         led = 1;
00255         buzzer = 0.5;
00256         wait(0.5);
00257         led = 0;
00258         buzzer = 0;
00259         wait(0.25);
00260         led = 1;
00261         buzzer = 0.5;
00262         wait(0.5);
00263         led = 0;
00264         buzzer = 0;
00265         wait(0.25);
00266         lcd.refresh();
00267         }
00268     /// quieter buzzer countdown to next update
00269     else {
00270         buzzer = 1;
00271         wait(0.5);
00272         buzzer = 0;
00273         wait(0.5);
00274         buzzer = 1;
00275         wait(0.5);
00276         buzzer = 0;
00277         wait(0.5);
00278         buzzer = 1;
00279         wait(0.5);
00280         buzzer = 0;
00281         wait(0.5);
00282         lcd.refresh();
00283     }
00284 
00285 }
00286 
00287 
00288 
00289 /// function to indicate object proximity on LED and buzzer in INCHES
00290 /// Buzzer counts down to sensor update
00291 /// LED and buzzer indicate when proximity is < 20 inches (~ 50 cm)
00292 void proximityIn() {
00293     
00294     int distance = sensor.getDistanceInch();
00295     
00296     /// beep at max volume (dutycycle = 50%) for 3 sec
00297     if (distance < 20) {
00298         led = 1;
00299         buzzer = 0.5;
00300         wait(0.5);
00301         led = 0;
00302         buzzer = 0;
00303         wait(0.25);
00304         led = 1;
00305         buzzer = 0.5;
00306         wait(0.5);
00307         led = 0;
00308         buzzer = 0;
00309         wait(0.25);
00310         led = 1;
00311         buzzer = 0.5;
00312         wait(0.5);
00313         led = 0;
00314         buzzer = 0;
00315         wait(0.25);
00316         led = 1;
00317         buzzer = 0.5;
00318         wait(0.5);
00319         led = 0;
00320         buzzer = 0;
00321         wait(0.25);
00322         lcd.refresh();
00323         }
00324     /// quieter buzzer countdown to next update
00325     else {
00326         buzzer = 1;
00327         wait(0.5);
00328         buzzer = 1;
00329         wait(0.5);
00330         buzzer = 1;
00331         wait(0.5);
00332         buzzer = 1;
00333         wait(0.5);
00334         buzzer = 1;
00335         wait(0.5);
00336         buzzer = 1;
00337         wait(0.5);
00338         /// clear screen and buffer
00339         lcd.clear();
00340     }
00341 
00342 }
00343 
00344 
00345 
00346 /// function to change units of readings: 0 - centimetres, 1 - inches
00347 void initMeasureIn() {
00348     
00349     if (unit == 0) {
00350         /// switch LED4 on to indicate unit
00351         leds = 8;
00352         centimetre();
00353     }
00354     
00355     if (unit == 1) {
00356         /// switch LED2 on to indicate unit
00357         leds = 2;
00358         inches();
00359     }
00360     
00361 }
00362 
00363 
00364 
00365 /// function to change display modes: 0 - normal display, 1 - inverted display
00366 void initDisplay() {
00367     
00368     if (pixel == 0) {
00369         normal();
00370     }
00371     
00372     if (pixel == 1) {
00373         invert();
00374     }
00375     
00376 }
00377 
00378 
00379 
00380 /// function to control screen backlight brightness
00381 void brightness() {
00382     lcd.setBrightness(POT);
00383 }
00384 
00385 
00386 
00387 /// function to set pixel display as black-on-white
00388 void normal() {
00389     lcd.normalMode();
00390 }
00391 
00392 
00393 
00394 /// function to set pixel display as white-on-black
00395 void invert() {
00396     lcd.inverseMode();    
00397 }
00398 
00399 
00400 
00401 /// function to read distances in centimetres
00402 void centimetre() {
00403         
00404         int distance = sensor.getDistanceCm();
00405         /// Print the formatted output from the sensor
00406         int length = sprintf(buffer,"D = %d cm",distance);
00407         
00408         /// Only allow data with length < or = 24 to be displayed
00409         if (length<= 14)
00410             lcd.printString(buffer,0,3);
00411             proximityCm();
00412             /// short delay before next measurement
00413             wait(0.5);
00414         
00415 }
00416 
00417 
00418 
00419 /// function to read distances in inches
00420 void inches() {
00421     
00422     int distance = sensor.getDistanceInch();
00423     /// Print the formatted output from the sensor
00424     int length = sprintf(buffer,"D = %d inches",distance);
00425             
00426     if (length<= 14)
00427         lcd.printString(buffer,0,3);
00428         proximityIn();
00429         /// short delay before next measurement
00430         wait(0.5);
00431 
00432 }
00433 
00434 
00435 
00436 /// function for radar display - not called because distance reading feature takes precedence in while loop
00437 /// Attempt at using a switch statement unsuccessful
00438 void radar() {
00439     
00440     lcd.clear();
00441     
00442     int distance = sensor.getDistanceCm();
00443     
00444     /// Assume max detectable distance is 240 cm.
00445     /// Dividing by 48 pixels across screen gives 5cm for every pixel.
00446     /// Set each pixel along the centre of the screen (x = 42) to 1
00447     /// for distance increases by 5 cm.
00448     /// Set any distance above 230cm to final pixel (41,48).
00449     if (distance < 5) {
00450         lcd.setPixel(42,1);
00451     }
00452     else if (distance < 10) {
00453         lcd.setPixel(42,2);
00454     }
00455     else if (distance < 15) {
00456         lcd.setPixel(42,3);
00457     }
00458     else if (distance < 20) {
00459         lcd.setPixel(42,4);
00460     }
00461     else if (distance < 25) {
00462         lcd.setPixel(42,5);
00463     }
00464     else if (distance < 30) {
00465         lcd.setPixel(42,6);
00466     }
00467     else if (distance < 35) {
00468         lcd.setPixel(42,7);
00469     }
00470     else if (distance < 40) {
00471         lcd.setPixel(42,8);
00472     }
00473     else if (distance < 45) {
00474         lcd.setPixel(42,9);
00475     }
00476     else if (distance < 50) {
00477         lcd.setPixel(42,10);
00478     }
00479     else if (distance < 55) {
00480         lcd.setPixel(42,11);
00481     }
00482     else if (distance < 60) {
00483         lcd.setPixel(42,12);
00484     }
00485     else if (distance < 65) {
00486         lcd.setPixel(42,13);
00487     }
00488     else if (distance < 70) {
00489         lcd.setPixel(42,14);
00490     }
00491     else if (distance < 75) {
00492         lcd.setPixel(42,15);
00493     }
00494     else if (distance < 80) {
00495         lcd.setPixel(42,16);
00496     }
00497     else if (distance < 85) {
00498         lcd.setPixel(42,17);
00499     }
00500     else if (distance < 90) {
00501         lcd.setPixel(42,18);
00502     }
00503     else if (distance < 95) {
00504         lcd.setPixel(42,19);
00505     }
00506     else if (distance < 100) {
00507         lcd.setPixel(42,20);
00508     }
00509     else if (distance < 105) {
00510         lcd.setPixel(42,21);
00511     }
00512     else if (distance < 110) {
00513         lcd.setPixel(42,22);
00514     }
00515     else if (distance < 115) {
00516         lcd.setPixel(42,23);
00517     }
00518     else if (distance < 120) {
00519         lcd.setPixel(42,24);
00520     }
00521     else if (distance < 125) {
00522         lcd.setPixel(42,25);
00523     }
00524     else if (distance < 130) {
00525         lcd.setPixel(42,26);
00526     }
00527     else if (distance < 135) {
00528         lcd.setPixel(42,27);
00529     }
00530     else if (distance < 140) {
00531         lcd.setPixel(42,28);
00532     }
00533     else if (distance < 145) {
00534         lcd.setPixel(42,29);
00535     }
00536     else if (distance < 150) {
00537         lcd.setPixel(42,30);
00538     }
00539     else if (distance < 155) {
00540         lcd.setPixel(42,31);
00541     }
00542     else if (distance < 160) {
00543         lcd.setPixel(42,32);
00544     }
00545     else if (distance < 165) {
00546         lcd.setPixel(42,33);
00547     }
00548     else if (distance < 170) {
00549         lcd.setPixel(42,34);
00550     }
00551     else if (distance < 175) {
00552         lcd.setPixel(42,35);
00553     }
00554     else if (distance < 180) {
00555         lcd.setPixel(42,36);
00556     }
00557     else if (distance < 185) {
00558         lcd.setPixel(42,37);
00559     }
00560     else if (distance < 190) {
00561         lcd.setPixel(42,38);
00562     }
00563     else if (distance < 195) {
00564         lcd.setPixel(42,39);
00565     }
00566     else if (distance < 200) {
00567         lcd.setPixel(42,40);
00568     }
00569     else if (distance < 205) {
00570         lcd.setPixel(42,41);
00571     }
00572     else if (distance < 210) {
00573         lcd.setPixel(42,42);
00574     }
00575     else if (distance < 215) {
00576         lcd.setPixel(42,43);
00577     }
00578     else if (distance < 220) {
00579         lcd.setPixel(42,44);
00580     }
00581     else if (distance < 225) {
00582         lcd.setPixel(42,45);
00583     }
00584     else if (distance < 230) {
00585         lcd.setPixel(42,46);
00586     }
00587     else {
00588         lcd.setPixel(42,47);
00589     }
00590     wait(3);
00591     lcd.refresh();
00592 }