Simple Electronic Angle Meter and Spirit Level.
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00001 /** 00002 @file main.cpp 00003 @brief Electronic Angle Meter and Spirit Level. 00004 @brief Revision 1.0. 00005 @author Shengyuan Chu 00006 @date May 2015 00007 */ 00008 00009 #include "mbed.h" 00010 #include "main.h" 00011 #include "MMA8452.h" 00012 #include "PowerControl/PowerControl.h" 00013 #include "PowerControl/EthernetPowerControl.h" 00014 00015 /** 00016 @brief Connect all components to mbed LPC1768. 00017 @brief Connect LCD to pin 7,8,9,10,11,13,26. 00018 @brief Connect Accelerometer to pin 27,28. 00019 @brief Connect buzzer to pin 21. 00020 @brief Connect button to pin 17. 00021 @brief Connect LEDs to pin 22,23,24,25. 00022 */ 00023 N5110 lcd(p7,p8,p9,p10,p11,p13,p26); 00024 MMA8452 mma8452(p28,p27); 00025 PwmOut buzzer(p21); 00026 DigitalIn pb(p17); 00027 DigitalOut ledA(p25); 00028 DigitalOut ledB(p23); 00029 DigitalOut ledC(p22); 00030 DigitalOut ledD(p24); 00031 00032 Serial serial(USBTX,USBRX); 00033 Timeout flipper; 00034 00035 /** 00036 @brief Function prototypes. 00037 */ 00038 void Switch (int functoion); 00039 void AngleMeter(); 00040 void SpiritLevel(); 00041 void fun1(); 00042 void fun2(); 00043 00044 /** 00045 @brief Different frequencies of buzzer. 00046 */ 00047 float frequency1 = 1046.5; 00048 float frequency2 = 1174.7; 00049 float frequency3 = 1318.5; 00050 00051 /** 00052 @brief Main function. 00053 @brief Call function of Angle Meter without pushing 00054 @brief button when power is initally turned on. 00055 */ 00056 int main() { 00057 00058 /**Power down Ethernet interface to save power.*/ 00059 PHY_PowerDown(); 00060 00061 /**Initialise LCD and set brightness to 0.8.*/ 00062 lcd.init(); 00063 lcd.normalMode(); 00064 lcd.setBrightness(0.8); 00065 00066 /**Display the name of Angle Meter function after the initialization of LCD.*/ 00067 lcd.printString("Electronic",12,2); 00068 lcd.printString("Angle Meter",10,3); 00069 00070 /**Call function of Angle Meter after 2 seconds' delay.*/ 00071 flipper.attach(&AngleMeter, 2.0); 00072 00073 /**Turn all the LEDs on when the power is initially turned on.*/ 00074 ledA=1; 00075 ledB=1; 00076 ledC=1; 00077 ledD=1; 00078 00079 /**Set button to PullDown mode.*/ 00080 pb.mode(PullDown); 00081 00082 /**Change the integer between 1 and 2 when button is pressed and send it to Switch function.*/ 00083 int function = 1; 00084 00085 while(1) { 00086 if (pb){ 00087 Switch(function); 00088 00089 /**Allow 0.2 second for button debounce.*/ 00090 wait(0.2); 00091 while (pb); 00092 {if (function == 2) function = 1; else function++;} 00093 } 00094 } 00095 } 00096 00097 /** 00098 @brief Switch functions between Angle Meter and Spirit Level. 00099 @param function - integer to change between 1 and 2. 00100 @return Call fun1() when function=2, call fun2() when function=1. 00101 */ 00102 void Switch (int function) 00103 { 00104 00105 switch (function) { 00106 case 1 : fun2(); 00107 break; 00108 case 2 : fun1(); 00109 break; 00110 } 00111 00112 } 00113 00114 /** 00115 @brief Display angles in two dimensions and indicate directions using arrows. 00116 */ 00117 void AngleMeter() 00118 { 00119 /**Initialise the accelerometer.*/ 00120 mma8452.init(); 00121 Acceleration acceleration; 00122 00123 /**Lower down the brightness of LCD to 0.5.*/ 00124 lcd.clear(); 00125 lcd.setBrightness(0.5); 00126 00127 /**When button is not pushed, main features of Angle Meter will be run.*/ 00128 while(!pb) { 00129 00130 /**Display 'degree' in the last line of LCD.*/ 00131 lcd.printString("degree",3,5); 00132 lcd.printString("degree",46,5); 00133 00134 /**Read value of acceleration.*/ 00135 acceleration = mma8452.readValues(); 00136 00137 float X=acceleration.x; 00138 float Y=acceleration.y; 00139 float Z=acceleration.z; 00140 00141 /**Calculate the angles in X and Y dimensions.*/ 00142 float Ax=atan(X/sqrt(pow(Y,2)+pow(Z,2)))/3.14159265358979323846*180; 00143 float Ay=atan(Y/sqrt(pow(X,2)+pow(Z,2)))/3.14159265358979323846*180; 00144 00145 /**Print formatted data to buffer.*/ 00146 char buffer1[14]; 00147 int length = sprintf(buffer1,"%.0f",abs(Ax)); 00148 char buffer2[14]; 00149 length = sprintf(buffer2,"%.0f",abs(Ay)); 00150 00151 /**Display values if string will fit on display.*/ 00152 if (length <= 14) // 00153 lcd.printString(buffer1,20,3); 00154 lcd.printString(buffer2,55,3); 00155 00156 /**LED C will be turned on if the angle in X dimension is larger than 20 degree.*/ 00157 if (Ax>20) 00158 ledC=1; 00159 else 00160 ledC=0; 00161 00162 /**LED A will be turned on if the angle in X dimension is smaller than -20 degree.*/ 00163 if (Ax<-20) 00164 ledA=1; 00165 else 00166 ledA=0; 00167 00168 /**LED D will be turned on if the angle in Y dimension is larger than 20 degree.*/ 00169 if (Ay>20) 00170 ledD=1; 00171 else 00172 ledD=0; 00173 00174 /**LED B will be turned on if the angle in Y dimension is smaller than -20 degree.*/ 00175 if (Ay<-20) 00176 ledB=1; 00177 else 00178 ledB=0; 00179 00180 /**Draw lines of the body of arrows.*/ 00181 lcd.drawLine(58,6,58,16,1); 00182 lcd.drawLine(17,11,29,11,1); 00183 lcd.refresh(); 00184 00185 /**Pixes will be set if the angle in Y dimension is larger than 0 degree.*/ 00186 if (Ay>=0){ 00187 lcd.setPixel(60,5); 00188 lcd.setPixel(59,5); 00189 lcd.setPixel(58,5); 00190 lcd.setPixel(57,5); 00191 lcd.setPixel(56,5); 00192 lcd.setPixel(59,4); 00193 lcd.setPixel(58,4); 00194 lcd.setPixel(57,4); 00195 lcd.setPixel(58,3); 00196 lcd.refresh(); 00197 } 00198 00199 /**Pixes will be set if the angle in Y dimension is smaller than 0 degree.*/ 00200 else if (Ay<=0) { 00201 lcd.setPixel(60,17); 00202 lcd.setPixel(59,17); 00203 lcd.setPixel(58,17); 00204 lcd.setPixel(57,17); 00205 lcd.setPixel(56,17); 00206 lcd.setPixel(59,18); 00207 lcd.setPixel(58,18); 00208 lcd.setPixel(57,18); 00209 lcd.setPixel(58,19); 00210 lcd.refresh(); 00211 } 00212 00213 /**Pixes will be set if the angle in X dimension is larger than 0 degree.*/ 00214 if (Ax>=0) { 00215 lcd.setPixel(30,13); 00216 lcd.setPixel(30,12); 00217 lcd.setPixel(30,11); 00218 lcd.setPixel(30,10); 00219 lcd.setPixel(30,9); 00220 lcd.setPixel(31,12); 00221 lcd.setPixel(31,11); 00222 lcd.setPixel(31,10); 00223 lcd.setPixel(32,11); 00224 lcd.refresh(); 00225 } 00226 00227 /**Pixes will be set if the angle in X dimension is smaller than 0 degree.*/ 00228 else if (Ax<=0) { 00229 lcd.setPixel(16,13); 00230 lcd.setPixel(16,12); 00231 lcd.setPixel(16,11); 00232 lcd.setPixel(16,10); 00233 lcd.setPixel(16,9); 00234 lcd.setPixel(15,12); 00235 lcd.setPixel(15,11); 00236 lcd.setPixel(15,10); 00237 lcd.setPixel(14,11); 00238 lcd.refresh(); 00239 } 00240 00241 /**Decrease the fluctuation of values.*/ 00242 wait(0.3); 00243 lcd.clear(); 00244 00245 /**Buzzer will beep in frequency 2 if the angle is between 50 and 75 degree.*/ 00246 if ((abs(Ax) >= 50 && abs(Ax) < 75)||(abs(Ay) >= 50 && abs(Ay) < 75)) { 00247 buzzer.period(1/frequency2); 00248 buzzer=0.1; 00249 } 00250 00251 /**Buzzer will beep in frequency 3 if the angle is beyond 75 degree.*/ 00252 else if ((abs(Ax) >= 75)||(abs(Ay) >= 75)) { 00253 buzzer.period(1/frequency3); 00254 buzzer=0.1; 00255 } 00256 00257 /**Buzzer will not beep.*/ 00258 else { 00259 buzzer.period(1/frequency1); 00260 buzzer=0; 00261 } 00262 } 00263 00264 /**When button is pushed, main features will stop.*/ 00265 while(pb) { 00266 break; 00267 } 00268 } 00269 00270 /** 00271 @brief Indicate the gradient in all directions by showing 00272 @brief the position of a group of pixes. 00273 */ 00274 void SpiritLevel() 00275 { 00276 /**Initialise all the LEDs to be off.*/ 00277 ledA=0; 00278 ledB=0; 00279 ledC=0; 00280 ledD=0; 00281 00282 /**Set the LCD to inverse mode and lower down the brightness to 0.5.*/ 00283 lcd.clear(); 00284 lcd.inverseMode(); 00285 lcd.setBrightness(0.5); 00286 00287 /**Initialise the accelerometer.*/ 00288 mma8452.init(); 00289 Acceleration acceleration; 00290 00291 /**When button is not pushed, main features of Spirit Level will be run.*/ 00292 while(!pb) { 00293 00294 /**Read value of acceleration.*/ 00295 acceleration = mma8452.readValues();//read value of acceleration 00296 00297 float Ax=acceleration.x; 00298 float Ay=acceleration.y; 00299 00300 /**Draw three circles and two lines.*/ 00301 lcd.drawCircle(41,24,23,0); 00302 lcd.drawCircle(41,24,4,0); 00303 lcd.drawCircle(41,24,13,0); 00304 lcd.drawLine(41,3,41,45,1); 00305 lcd.drawLine(20,24,62,24,1); 00306 lcd.refresh(); 00307 00308 /**Pixes will be displayed if acceleration values are within -0.4 and 0.4.*/ 00309 if (abs(Ax)<=0.4&&abs(Ay)<=0.4) { 00310 00311 float X=Ax/0.018; 00312 float Y=Ay/0.018; 00313 00314 lcd.setPixel(42+X, 26-Y); 00315 lcd.setPixel(41+X, 26-Y); 00316 lcd.setPixel(40+X, 26-Y); 00317 lcd.setPixel(43+X, 25-Y); 00318 lcd.setPixel(42+X, 25-Y); 00319 lcd.setPixel(41+X, 25-Y); 00320 lcd.setPixel(40+X, 25-Y); 00321 lcd.setPixel(39+X, 25-Y); 00322 lcd.setPixel(43+X, 24-Y); 00323 lcd.setPixel(42+X, 24-Y); 00324 lcd.setPixel(41+X, 24-Y); 00325 lcd.setPixel(40+X, 24-Y); 00326 lcd.setPixel(39+X, 24-Y); 00327 lcd.setPixel(43+X, 23-Y); 00328 lcd.setPixel(42+X, 23-Y); 00329 lcd.setPixel(41+X, 23-Y); 00330 lcd.setPixel(40+X, 23-Y); 00331 lcd.setPixel(39+X, 23-Y); 00332 lcd.setPixel(42+X, 22-Y); 00333 lcd.setPixel(41+X, 22-Y); 00334 lcd.setPixel(40+X, 22-Y); 00335 lcd.refresh(); 00336 00337 /**Displayed pixes will be cleared after 0.2 second.*/ 00338 wait(0.2); 00339 00340 lcd.clearPixel(42+X, 26-Y); 00341 lcd.clearPixel(41+X, 26-Y); 00342 lcd.clearPixel(40+X, 26-Y); 00343 lcd.clearPixel(43+X, 25-Y); 00344 lcd.clearPixel(42+X, 25-Y); 00345 lcd.clearPixel(41+X, 25-Y); 00346 lcd.clearPixel(40+X, 25-Y); 00347 lcd.clearPixel(39+X, 25-Y); 00348 lcd.clearPixel(43+X, 24-Y); 00349 lcd.clearPixel(42+X, 24-Y); 00350 lcd.clearPixel(41+X, 24-Y); 00351 lcd.clearPixel(40+X, 24-Y); 00352 lcd.clearPixel(39+X, 24-Y); 00353 lcd.clearPixel(43+X, 23-Y); 00354 lcd.clearPixel(42+X, 23-Y); 00355 lcd.clearPixel(41+X, 23-Y); 00356 lcd.clearPixel(40+X, 23-Y); 00357 lcd.clearPixel(39+X, 23-Y); 00358 lcd.clearPixel(42+X, 22-Y); 00359 lcd.clearPixel(41+X, 22-Y); 00360 lcd.clearPixel(40+X, 22-Y); 00361 lcd.refresh(); 00362 } 00363 00364 /**All LEDs will be turned on if acceleration values are within -0.05 and 0.05.*/ 00365 if (abs(Ax)<=0.05&&abs(Ay)<=0.05) { 00366 ledA=1; 00367 ledB=1; 00368 ledC=1; 00369 ledD=1; 00370 } 00371 00372 /**All LEDs will be turned off if acceleration values go beyond this range.*/ 00373 else { 00374 ledA=0; 00375 ledB=0; 00376 ledC=0; 00377 ledD=0; 00378 } 00379 } 00380 } 00381 00382 /** 00383 @brief Display the function name of Angle Meter for 1 second before calling it. 00384 */ 00385 void fun1() 00386 { 00387 /**Initialise the LCD and set brightness to 0.8.*/ 00388 lcd.init(); 00389 lcd.normalMode(); 00390 lcd.setBrightness(0.8); 00391 lcd.clear(); 00392 00393 /**Display the function name of Angle Meter.*/ 00394 lcd.printString("Electronic",12,2); 00395 lcd.printString("Angle Meter",10,3); 00396 00397 /**Turn LED A and LED C on.*/ 00398 ledA=1; 00399 ledB=0; 00400 ledC=1; 00401 ledD=0; 00402 00403 /**Call function of Angle Meter after 1 second delay.*/ 00404 flipper.attach(&AngleMeter, 1.0); 00405 } 00406 00407 /** 00408 @brief Display the function name of Spirit Level for 1 second before calling it. 00409 */ 00410 void fun2() 00411 { 00412 /**Turn off the buzzer.*/ 00413 buzzer = 0; 00414 00415 /**Initialise the LCD and set brightness to 0.8.*/ 00416 lcd.init(); 00417 lcd.normalMode(); 00418 lcd.setBrightness(0.8); 00419 lcd.clear(); 00420 00421 /**Display the function name of Spirit Level.*/ 00422 lcd.printString("Electronic",12,2); 00423 lcd.printString("Spirit Level",7,3); 00424 00425 /**Turn LED B and LED D on.*/ 00426 ledA=0; 00427 ledB=1; 00428 ledC=0; 00429 ledD=1; 00430 00431 /**Call function of Spirit Level after 1 second delay.*/ 00432 flipper.attach(&SpiritLevel, 1.0); 00433 } 00434 00435 /** 00436 @brief Power down the Ethernet interface to save power. 00437 @brief Acknowledgements to Michael Wei's code. 00438 */ 00439 void PHY_PowerDown() 00440 { 00441 if (!Peripheral_GetStatus(LPC1768_PCONP_PCENET)) 00442 EMAC_Init(); //init EMAC if it is not already init'd 00443 00444 unsigned int regv; 00445 regv = read_PHY(PHY_REG_BMCR); 00446 write_PHY(PHY_REG_BMCR, regv | (1 << PHY_REG_BMCR_POWERDOWN)); 00447 regv = read_PHY(PHY_REG_BMCR); 00448 00449 //shouldn't need the EMAC now. 00450 Peripheral_PowerDown(LPC1768_PCONP_PCENET); 00451 00452 //and turn off the PHY OSC 00453 LPC_GPIO1->FIODIR |= 0x8000000; 00454 LPC_GPIO1->FIOCLR = 0x8000000; 00455 } 00456 00457 static void write_PHY (unsigned int PhyReg, unsigned short Value) { 00458 /* Write a data 'Value' to PHY register 'PhyReg'. */ 00459 unsigned int tout; 00460 /* Hardware MII Management for LPC176x devices. */ 00461 LPC_EMAC->MADR = DP83848C_DEF_ADR | PhyReg; 00462 LPC_EMAC->MWTD = Value; 00463 00464 /* Wait utill operation completed */ 00465 for (tout = 0; tout < MII_WR_TOUT; tout++) { 00466 if ((LPC_EMAC->MIND & MIND_BUSY) == 0) { 00467 break; 00468 } 00469 } 00470 } 00471 00472 static unsigned short read_PHY (unsigned int PhyReg) { 00473 /* Read a PHY register 'PhyReg'. */ 00474 unsigned int tout, val; 00475 00476 LPC_EMAC->MADR = DP83848C_DEF_ADR | PhyReg; 00477 LPC_EMAC->MCMD = MCMD_READ; 00478 00479 /* Wait until operation completed */ 00480 for (tout = 0; tout < MII_RD_TOUT; tout++) { 00481 if ((LPC_EMAC->MIND & MIND_BUSY) == 0) { 00482 break; 00483 } 00484 } 00485 LPC_EMAC->MCMD = 0; 00486 val = LPC_EMAC->MRDD; 00487 00488 return (val); 00489 } 00490 00491 void EMAC_Init() 00492 { 00493 unsigned int tout,regv; 00494 /* Power Up the EMAC controller. */ 00495 Peripheral_PowerUp(LPC1768_PCONP_PCENET); 00496 00497 LPC_PINCON->PINSEL2 = 0x50150105; 00498 LPC_PINCON->PINSEL3 &= ~0x0000000F; 00499 LPC_PINCON->PINSEL3 |= 0x00000005; 00500 00501 /* Reset all EMAC internal modules. */ 00502 LPC_EMAC->MAC1 = MAC1_RES_TX | MAC1_RES_MCS_TX | MAC1_RES_RX | MAC1_RES_MCS_RX | 00503 MAC1_SIM_RES | MAC1_SOFT_RES; 00504 LPC_EMAC->Command = CR_REG_RES | CR_TX_RES | CR_RX_RES; 00505 00506 /* A short delay after reset. */ 00507 for (tout = 100; tout; tout--); 00508 00509 /* Initialize MAC control registers. */ 00510 LPC_EMAC->MAC1 = MAC1_PASS_ALL; 00511 LPC_EMAC->MAC2 = MAC2_CRC_EN | MAC2_PAD_EN; 00512 LPC_EMAC->MAXF = ETH_MAX_FLEN; 00513 LPC_EMAC->CLRT = CLRT_DEF; 00514 LPC_EMAC->IPGR = IPGR_DEF; 00515 00516 /* Enable Reduced MII interface. */ 00517 LPC_EMAC->Command = CR_RMII | CR_PASS_RUNT_FRM; 00518 00519 /* Reset Reduced MII Logic. */ 00520 LPC_EMAC->SUPP = SUPP_RES_RMII; 00521 for (tout = 100; tout; tout--); 00522 LPC_EMAC->SUPP = 0; 00523 00524 /* Put the DP83848C in reset mode */ 00525 write_PHY (PHY_REG_BMCR, 0x8000); 00526 00527 /* Wait for hardware reset to end. */ 00528 for (tout = 0; tout < 0x100000; tout++) { 00529 regv = read_PHY (PHY_REG_BMCR); 00530 if (!(regv & 0x8000)) { 00531 /* Reset complete */ 00532 break; 00533 } 00534 } 00535 } 00536 00537 /** 00538 @brief Functions used to display characters and shapes. 00539 @brief Acknowledgements to Dr.Craig A. Evans's code. 00540 */ 00541 N5110::N5110(PinName pwrPin, PinName scePin, PinName rstPin, PinName dcPin, PinName mosiPin, PinName sclkPin, PinName ledPin) 00542 { 00543 00544 spi = new SPI(mosiPin,NC,sclkPin); // create new SPI instance and initialise 00545 initSPI(); 00546 00547 // set up pins as required 00548 led = new PwmOut(ledPin); 00549 pwr = new DigitalOut(pwrPin); 00550 sce = new DigitalOut(scePin); 00551 rst = new DigitalOut(rstPin); 00552 dc = new DigitalOut(dcPin); 00553 00554 } 00555 00556 // initialise function - powers up and sends the initialisation commands 00557 void N5110::init() 00558 { 00559 turnOn(); // power up 00560 wait_ms(10); // small delay seems to prevent spurious pixels during mbed reset 00561 reset(); // reset LCD - must be done within 100 ms 00562 00563 // function set - extended 00564 sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE); 00565 // Don't completely understand these parameters - they seem to work as they are 00566 // Consult the datasheet if you need to change them 00567 sendCommand(CMD_VOP_7V38); // operating voltage - these values are from Chris Yan's Library 00568 sendCommand(CMD_TC_TEMP_2); // temperature control 00569 sendCommand(CMD_BI_MUX_48); // bias 00570 00571 // function set - basic 00572 sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE); 00573 normalMode(); // normal video mode by default 00574 sendCommand(CMD_DC_NORMAL_MODE); // black on white 00575 00576 // RAM is undefined at power-up so clear 00577 clearRAM(); 00578 00579 } 00580 00581 // sets normal video mode (black on white) 00582 void N5110::normalMode() 00583 { 00584 sendCommand(CMD_DC_NORMAL_MODE); 00585 00586 } 00587 00588 // sets normal video mode (white on black) 00589 void N5110::inverseMode() 00590 { 00591 sendCommand(CMD_DC_INVERT_VIDEO); 00592 } 00593 00594 // function to power up the LCD and backlight 00595 void N5110::turnOn() 00596 { 00597 // set brightness of LED - 0.0 to 1.0 - default is 50% 00598 setBrightness(0.5); 00599 pwr->write(1); // apply power 00600 } 00601 00602 // function to power down LCD 00603 void N5110::turnOff() 00604 { 00605 setBrightness(0.0); // turn backlight off 00606 clearRAM(); // clear RAM to ensure specified current consumption 00607 // send command to ensure we are in basic mode 00608 sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE); 00609 // clear the display 00610 sendCommand(CMD_DC_CLEAR_DISPLAY); 00611 // enter the extended mode and power down 00612 sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE); 00613 // small delay and then turn off the power pin 00614 wait_ms(10); 00615 pwr->write(0); 00616 00617 } 00618 00619 // function to change LED backlight brightness 00620 void N5110::setBrightness(float brightness) 00621 { 00622 // check whether brightness is within range 00623 if (brightness < 0.0) 00624 brightness = 0.0; 00625 if (brightness > 1.0) 00626 brightness = 1.0; 00627 // set PWM duty cycle 00628 led->write(brightness); 00629 } 00630 00631 // pulse the active low reset line 00632 void N5110::reset() 00633 { 00634 rst->write(0); // reset the LCD 00635 rst->write(1); 00636 } 00637 00638 // function to initialise SPI peripheral 00639 void N5110::initSPI() 00640 { 00641 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 00642 spi->frequency(4000000); // maximum of screen is 4 MHz 00643 } 00644 00645 // send a command to the display 00646 void N5110::sendCommand(unsigned char command) 00647 { 00648 dc->write(0); // set DC low for command 00649 sce->write(0); // set CE low to begin frame 00650 spi->write(command); // send command 00651 dc->write(1); // turn back to data by default 00652 sce->write(1); // set CE high to end frame (expected for transmission of single byte) 00653 00654 } 00655 00656 // this function writes 0 to the 504 bytes to clear the RAM 00657 void N5110::clearRAM() 00658 { 00659 int i; 00660 sce->write(0); //set CE low to begin frame 00661 for(i = 0; i < WIDTH * HEIGHT; i++) { // 48 x 84 bits = 504 bytes 00662 spi->write(0x00); // send 0's 00663 } 00664 sce->write(1); // set CE high to end frame 00665 00666 } 00667 00668 // function to set the XY address in RAM for subsequenct data write 00669 void N5110::setXYAddress(int x, int y) 00670 { 00671 if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range 00672 sendCommand(0x80 | x); // send addresses to display with relevant mask 00673 sendCommand(0x40 | y); 00674 } 00675 } 00676 00677 // These functions are used to set, clear and get the value of pixels in the display 00678 // Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x). The refresh() 00679 // function must be called after set and clear in order to update the display 00680 void N5110::setPixel(int x, int y) 00681 { 00682 if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range 00683 // calculate bank and shift 1 to required position in the data byte 00684 buffer[x][y/8] |= (1 << y%8); 00685 } 00686 } 00687 00688 void N5110::clearPixel(int x, int y) 00689 { 00690 if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range 00691 // calculate bank and shift 1 to required position (using bit clear) 00692 buffer[x][y/8] &= ~(1 << y%8); 00693 } 00694 } 00695 00696 // function to refresh the display 00697 void N5110::refresh() 00698 { 00699 int i,j; 00700 00701 setXYAddress(0,0); // important to set address back to 0,0 before refreshing display 00702 // address auto increments after printing string, so buffer[0][0] will not coincide 00703 // with top-left pixel after priting string 00704 00705 sce->write(0); //set CE low to begin frame 00706 00707 for(j = 0; j < BANKS; j++) { // be careful to use correct order (j,i) for horizontal addressing 00708 for(i = 0; i < WIDTH; i++) { 00709 spi->write(buffer[i][j]); // send buffer 00710 } 00711 } 00712 sce->write(1); // set CE high to end frame 00713 00714 } 00715 00716 // function to print string at specified position 00717 void N5110::printString(const char * str,int x,int y) 00718 { 00719 if (y>=0 && y<BANKS) { // check if printing in range of y banks 00720 00721 int n = 0 ; // counter for number of characters in string 00722 // loop through string and print character 00723 while(*str) { 00724 00725 // writes the character bitmap data to the buffer, so that 00726 // text and pixels can be displayed at the same time 00727 for (int i = 0; i < 5 ; i++ ) { 00728 int pixel_x = x+i+n*6; 00729 if (pixel_x > WIDTH-1) // ensure pixel isn't outside the buffer size (0 - 83) 00730 break; 00731 buffer[pixel_x][y] = font5x7[(*str - 32)*5 + i]; 00732 } 00733 00734 str++; // go to next character in string 00735 00736 n++; // increment index 00737 00738 } 00739 00740 refresh(); // this sends the buffer to the display and sets address (cursor) back to 0,0 00741 } 00742 } 00743 00744 // function to clear the screen 00745 void N5110::clear() 00746 { 00747 clearBuffer(); // clear the buffer then call the refresh function 00748 refresh(); 00749 } 00750 00751 // function to clear the buffer 00752 void N5110::clearBuffer() 00753 { 00754 int i,j; 00755 for (i=0; i<WIDTH; i++) { // loop through the banks and set the buffer to 0 00756 for (j=0; j<BANKS; j++) { 00757 buffer[i][j]=0; 00758 } 00759 } 00760 } 00761 00762 // function to draw circle 00763 void N5110:: drawCircle(int x0,int y0,int radius,int fill) 00764 { 00765 // from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm 00766 int x = radius; 00767 int y = 0; 00768 int radiusError = 1-x; 00769 00770 while(x >= y) { 00771 00772 // if transparent, just draw outline 00773 if (fill == 0) { 00774 setPixel( x + x0, y + y0); 00775 setPixel(-x + x0, y + y0); 00776 setPixel( y + x0, x + y0); 00777 setPixel(-y + x0, x + y0); 00778 setPixel(-y + x0, -x + y0); 00779 setPixel( y + x0, -x + y0); 00780 setPixel( x + x0, -y + y0); 00781 setPixel(-x + x0, -y + y0); 00782 } else { // drawing filled circle, so draw lines between points at same y value 00783 00784 int type = (fill==1) ? 1:0; // black or white fill 00785 00786 drawLine(x+x0,y+y0,-x+x0,y+y0,type); 00787 drawLine(y+x0,x+y0,-y+x0,x+y0,type); 00788 drawLine(y+x0,-x+y0,-y+x0,-x+y0,type); 00789 drawLine(x+x0,-y+y0,-x+x0,-y+y0,type); 00790 } 00791 00792 00793 y++; 00794 if (radiusError<0) { 00795 radiusError += 2 * y + 1; 00796 } else { 00797 x--; 00798 radiusError += 2 * (y - x) + 1; 00799 } 00800 } 00801 00802 } 00803 00804 void N5110::drawLine(int x0,int y0,int x1,int y1,int type) 00805 { 00806 int y_range = y1-y0; // calc range of y and x 00807 int x_range = x1-x0; 00808 int start,stop,step; 00809 00810 // if dotted line, set step to 2, else step is 1 00811 step = (type==2) ? 2:1; 00812 00813 // make sure we loop over the largest range to get the most pixels on the display 00814 // for instance, if drawing a vertical line (x_range = 0), we need to loop down the y pixels 00815 // or else we'll only end up with 1 pixel in the x column 00816 if ( abs(x_range) > abs(y_range) ) { 00817 00818 // ensure we loop from smallest to largest or else for-loop won't run as expected 00819 start = x1>x0 ? x0:x1; 00820 stop = x1>x0 ? x1:x0; 00821 00822 // loop between x pixels 00823 for (int x = start; x<= stop ; x+=step) { 00824 // do linear interpolation 00825 int y = y0 + (y1-y0)*(x-x0)/(x1-x0); 00826 00827 if (type == 0) // if 'white' line, turn off pixel 00828 clearPixel(x,y); 00829 else 00830 setPixel(x,y); // else if 'black' or 'dotted' turn on pixel 00831 } 00832 } else { 00833 00834 // ensure we loop from smallest to largest or else for-loop won't run as expected 00835 start = y1>y0 ? y0:y1; 00836 stop = y1>y0 ? y1:y0; 00837 00838 for (int y = start; y<= stop ; y+=step) { 00839 // do linear interpolation 00840 int x = x0 + (x1-x0)*(y-y0)/(y1-y0); 00841 00842 if (type == 0) // if 'white' line, turn off pixel 00843 clearPixel(x,y); 00844 else 00845 setPixel(x,y); // else if 'black' or 'dotted' turn on pixel 00846 00847 } 00848 } 00849 00850 } 00851 00852 MMA8452:: MMA8452(PinName sdaPin, PinName sclPin) 00853 { 00854 i2c = new I2C(sdaPin,sclPin); // create new I2C instance and initialise 00855 i2c->frequency(400000); // I2C Fast Mode - 400kHz 00856 leds = new BusOut(LED4,LED3,LED2,LED1); // for debug 00857 } 00858 00859 void MMA8452::init() 00860 { 00861 00862 i2c->frequency(400000); // set Fast Mode I2C frequency (5.10 datasheet) 00863 00864 char data = readByteFromRegister(WHO_AM_I); // p18 datasheet 00865 if (data != 0x2A) { // if correct ID not found, hand and flash error message 00866 error(); 00867 } 00868 00869 // put into STANDBY while configuring 00870 data = readByteFromRegister(CTRL_REG1); // get current value of register 00871 data &= ~(1<<0); // clear bit 0 (p37 datasheet) 00872 sendByteToRegister(data,CTRL_REG1); 00873 00874 // Set output data rate, default is 800 Hz, will set to 100 Hz (clear b5, set b4/b3 - p37 datasheet) 00875 data = readByteFromRegister(CTRL_REG1); 00876 data &= ~(1<<5); 00877 data |= (1<<4); 00878 data |= (1<<3); 00879 sendByteToRegister(data,CTRL_REG1); 00880 00881 //// Can also change default 2g range to 4g or 8g (p22 datasheet) 00882 data = readByteFromRegister(XYZ_DATA_CFG); 00883 data |= (1<<0); // set bit 0 - 4g range 00884 sendByteToRegister(data,XYZ_DATA_CFG); 00885 00886 // set ACTIVE 00887 data = readByteFromRegister(CTRL_REG1); 00888 data |= (1<<0); // set bit 0 in CTRL_REG1 00889 sendByteToRegister(data,CTRL_REG1); 00890 00891 } 00892 00893 // read acceleration data from device 00894 Acceleration MMA8452::readValues() 00895 { 00896 // acceleration data stored in 6 registers (0x01 to 0x06) 00897 // device automatically increments register, so can read 6 bytes starting from OUT_X_MSB 00898 char data[6]; 00899 readBytesFromRegister(OUT_X_MSB,6,data); 00900 00901 char x_MSB = data[0]; // extract MSB and LSBs for x,y,z values 00902 char x_LSB = data[1]; 00903 char y_MSB = data[2]; 00904 char y_LSB = data[3]; 00905 char z_MSB = data[4]; 00906 char z_LSB = data[5]; 00907 00908 // [0:7] of MSB are 8 MSB of 12-bit value , [7:4] of LSB are 4 LSB's of 12-bit value 00909 // need to type-cast as numbers are in signed (2's complement) form (p20 datasheet) 00910 int x = (int16_t) (x_MSB << 8) | x_LSB; // combine bytes 00911 x >>= 4; // are left-aligned, so shift 4 places right to right-align 00912 int y = (int16_t) (y_MSB << 8) | y_LSB; 00913 y >>= 4; 00914 int z = (int16_t) (z_MSB << 8) | z_LSB; 00915 z >>= 4; 00916 00917 // sensitivity is 1024 counts/g in 2g mode (pg 9 datasheet) 00918 // " " 512 " 4g " 00919 // " " 256 " 8g " 00920 Acceleration acc; 00921 00922 acc.x = x/512.0; 00923 acc.y = y/512.0; 00924 acc.z = z/512.0; 00925 00926 return acc; 00927 } 00928 00929 // reads a byte from a specific register 00930 char MMA8452::readByteFromRegister(char reg) 00931 { 00932 int nack = i2c->write(MMA8452_W_ADDRESS,®,1,true); // send the register address to the slave 00933 // true as need to send repeated start condition (5.10.1 datasheet) 00934 // http://www.i2c-bus.org/repeated-start-condition/ 00935 if (nack) 00936 error(); // if we don't receive acknowledgement, flash error message 00937 00938 char rx; 00939 nack = i2c->read(MMA8452_R_ADDRESS,&rx,1); // read a byte from the register and store in buffer 00940 if (nack) 00941 error(); // if we don't receive acknowledgement, flash error message 00942 00943 return rx; 00944 } 00945 00946 // reads a series of bytes, starting from a specific register 00947 void MMA8452::readBytesFromRegister(char reg,int numberOfBytes,char bytes[]) 00948 { 00949 00950 int nack = i2c->write(MMA8452_W_ADDRESS,®,1,true); // send the slave write address and the configuration register address 00951 // true as need to send repeated start condition (5.10.1 datasheet) 00952 // http://www.i2c-bus.org/repeated-start-condition/ 00953 00954 if (nack) 00955 error(); // if we don't receive acknowledgement, flash error message 00956 00957 nack = i2c->read(MMA8452_R_ADDRESS,bytes,numberOfBytes); // read bytes 00958 if (nack) 00959 error(); // if we don't receive acknowledgement, flash error message 00960 00961 } 00962 00963 // sends a byte to a specific register 00964 void MMA8452::sendByteToRegister(char byte,char reg) 00965 { 00966 char data[2]; 00967 data[0] = reg; 00968 data[1] = byte; 00969 // send the register address, followed by the data 00970 int nack = i2c->write(MMA8452_W_ADDRESS,data,2); 00971 if (nack) 00972 error(); // if we don't receive acknowledgement, flash error message 00973 00974 } 00975 00976 void MMA8452::error() 00977 { 00978 while(1) { 00979 leds->write(15); 00980 wait(0.1); 00981 leds->write(0); 00982 wait(0.1); 00983 } 00984 } 00985 00986 00987 00988
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