Shengyuan Chu
Simple Electronic Angle Meter and Spirit Level.
Diff: main.cpp
- Revision:
- 0:2885d4453e88
- Child:
- 1:f167423f6f0c
diff -r 000000000000 -r 2885d4453e88 main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Mon May 11 12:24:48 2015 +0000
@@ -0,0 +1,988 @@
+/**
+@file main.cpp
+@brief Electronic Angle Meter and Gradienter.
+@brief Revision 1.0.
+@author Shengyuan Chu
+@date May 2015
+*/
+
+#include "mbed.h"
+#include "main.h"
+#include "MMA8452.h"
+#include "PowerControl/PowerControl.h"
+#include "PowerControl/EthernetPowerControl.h"
+
+/**
+@brief Connect all components to mbed LPC1768.
+@brief Connect LCD to pin 7,8,9,10,11,13,26.
+@brief Connect Accelerometer to pin 27,28.
+@brief Connect buzzer to pin 21.
+@brief Connect button to pin 17.
+@brief Connect LEDs to pin 22,23,24,25.
+*/
+N5110 lcd(p7,p8,p9,p10,p11,p13,p26);
+MMA8452 mma8452(p28,p27);
+PwmOut buzzer(p21);
+DigitalIn pb(p17);
+DigitalOut ledA(p25);
+DigitalOut ledB(p23);
+DigitalOut ledC(p22);
+DigitalOut ledD(p24);
+
+Serial serial(USBTX,USBRX);
+Timeout flipper;
+
+/**
+@brief Function prototypes.
+*/
+void Switch (int functoion);
+void AngleMeter();
+void Gradienter();
+void fun1();
+void fun2();
+
+/**
+@brief Different frequencies of buzzer.
+*/
+float frequency1 = 440;
+float frequency2 = 554;
+float frequency3 = 659;
+
+/**
+@brief Main function.
+@brief Call function of Angle Meter without pushing
+@brief button when power is initally turned on.
+*/
+int main() {
+
+ /**Power down Ethernet interface to save power.*/
+ PHY_PowerDown();
+
+ /**Initialise LCD and set brightness to 0.8.*/
+ lcd.init();
+ lcd.normalMode();
+ lcd.setBrightness(0.8);
+
+ /**Display the name of Angle Meter function after the initialization of LCD.*/
+ lcd.printString("Electronic",12,2);
+ lcd.printString("Angle Meter",10,3);
+
+ /**Call function of Angle Meter after 2 seconds' delay.*/
+ flipper.attach(&AngleMeter, 2.0);
+
+ /**Turn all the LEDs on when the power is initially turned on.*/
+ ledA=1;
+ ledB=1;
+ ledC=1;
+ ledD=1;
+
+ /**Set button to PullDown mode.*/
+ pb.mode(PullDown);
+
+ /**Change the integer between 1 and 2 when button is pressed and send it to Switch function.*/
+ int function = 1;
+
+ while(1) {
+ if (pb){
+ Switch(function);
+
+ /**Allow 0.2 second for button debounce.*/
+ wait(0.2);
+ while (pb);
+ {if (function == 2) function = 1; else function++;}
+ }
+ }
+}
+
+/**
+@brief Switch functions between Angle Meter and Gradienter.
+@param function - integer to change between 1 and 2.
+@return Call fun1() when function=2, call fun2() when function=1.
+*/
+void Switch (int function)
+{
+
+ switch (function) {
+ case 1 : fun2();
+ break;
+ case 2 : fun1();
+ break;
+ }
+
+}
+
+ /**
+ @brief Display angles in two dimensions and indicate directions using arrows.
+ */
+void AngleMeter()
+{
+ /**Initialise the accelerometer.*/
+ mma8452.init();
+ Acceleration acceleration;
+
+ /**Lower down the brightness of LCD to 0.5.*/
+ lcd.clear();
+ lcd.setBrightness(0.5);
+
+ /**When button is not pushed, main features of Angle Meter will be run.*/
+ while(!pb) {
+
+ /**Display 'degree' in the last line of LCD.*/
+ lcd.printString("degree",3,5);
+ lcd.printString("degree",46,5);
+
+ /**Read value of acceleration.*/
+ acceleration = mma8452.readValues();
+
+ float X=acceleration.x;
+ float Y=acceleration.y;
+ float Z=acceleration.z;
+
+ /**Calculate the angles in X and Y dimensions.*/
+ float Ax=atan(X/sqrt(pow(Y,2)+pow(Z,2)))/3.14159265358979323846*180;
+ float Ay=atan(Y/sqrt(pow(X,2)+pow(Z,2)))/3.14159265358979323846*180;
+
+ /**Print formatted data to buffer.*/
+ char buffer1[14];
+ int length = sprintf(buffer1,"%.0f",abs(Ax));
+ char buffer2[14];
+ length = sprintf(buffer2,"%.0f",abs(Ay));
+
+ /**Display values if string will fit on display.*/
+ if (length <= 14) //
+ lcd.printString(buffer1,20,3);
+ lcd.printString(buffer2,55,3);
+
+ /**LED C will be turned on if the angle in X dimension is larger than 20 degree.*/
+ if (Ax>20)
+ ledC=1;
+ else
+ ledC=0;
+
+ /**LED A will be turned on if the angle in X dimension is smaller than -20 degree.*/
+ if (Ax<-20)
+ ledA=1;
+ else
+ ledA=0;
+
+ /**LED D will be turned on if the angle in Y dimension is larger than 20 degree.*/
+ if (Ay>20)
+ ledD=1;
+ else
+ ledD=0;
+
+ /**LED B will be turned on if the angle in Y dimension is smaller than -20 degree.*/
+ if (Ay<-20)
+ ledB=1;
+ else
+ ledB=0;
+
+ /**Draw lines of the body of arrows.*/
+ lcd.drawLine(58,6,58,16,1);
+ lcd.drawLine(17,11,29,11,1);
+ lcd.refresh();
+
+ /**Pixes will be set if the angle in Y dimension is larger than 0 degree.*/
+ if (Ay>=0){
+ lcd.setPixel(60,5);
+ lcd.setPixel(59,5);
+ lcd.setPixel(58,5);
+ lcd.setPixel(57,5);
+ lcd.setPixel(56,5);
+ lcd.setPixel(59,4);
+ lcd.setPixel(58,4);
+ lcd.setPixel(57,4);
+ lcd.setPixel(58,3);
+ lcd.refresh();
+ }
+
+ /**Pixes will be set if the angle in Y dimension is smaller than 0 degree.*/
+ else if (Ay<=0) {
+ lcd.setPixel(60,17);
+ lcd.setPixel(59,17);
+ lcd.setPixel(58,17);
+ lcd.setPixel(57,17);
+ lcd.setPixel(56,17);
+ lcd.setPixel(59,18);
+ lcd.setPixel(58,18);
+ lcd.setPixel(57,18);
+ lcd.setPixel(58,19);
+ lcd.refresh();
+ }
+
+ /**Pixes will be set if the angle in X dimension is larger than 0 degree.*/
+ if (Ax>=0) {
+ lcd.setPixel(30,13);
+ lcd.setPixel(30,12);
+ lcd.setPixel(30,11);
+ lcd.setPixel(30,10);
+ lcd.setPixel(30,9);
+ lcd.setPixel(31,12);
+ lcd.setPixel(31,11);
+ lcd.setPixel(31,10);
+ lcd.setPixel(32,11);
+ lcd.refresh();
+ }
+
+ /**Pixes will be set if the angle in X dimension is smaller than 0 degree.*/
+ else if (Ax<=0) {
+ lcd.setPixel(16,13);
+ lcd.setPixel(16,12);
+ lcd.setPixel(16,11);
+ lcd.setPixel(16,10);
+ lcd.setPixel(16,9);
+ lcd.setPixel(15,12);
+ lcd.setPixel(15,11);
+ lcd.setPixel(15,10);
+ lcd.setPixel(14,11);
+ lcd.refresh();
+ }
+
+ /**Decrease the fluctuation of values.*/
+ wait(0.3);
+ lcd.clear();
+
+ /**Buzzer will beep in frequency 2 if the angle is between 50 and 75 degree.*/
+ if ((abs(Ax) >= 50 && abs(Ax) < 75)||(abs(Ay) >= 50 && abs(Ay) < 75)) {
+ buzzer.period(1/frequency2);
+ buzzer=0.1;
+ }
+
+ /**Buzzer will beep in frequency 3 if the angle is beyond 75 degree.*/
+ else if ((abs(Ax) >= 75)||(abs(Ay) >= 75)) {
+ buzzer.period(1/frequency3);
+ buzzer=0.1;
+ }
+
+ /**Buzzer will not beep.*/
+ else {
+ buzzer.period(1/frequency1);
+ buzzer=0;
+ }
+ }
+
+ /**When button is pushed, main features will stop.*/
+ while(pb) {
+ break;
+ }
+}
+
+/**
+@brief Indicate the gradient in all directions by showing
+@brief the position of a group of pixes.
+*/
+void Gradienter()
+{
+ /**Initialise all the LEDs to be off.*/
+ ledA=0;
+ ledB=0;
+ ledC=0;
+ ledD=0;
+
+ /**Set the LCD to inverse mode and lower down the brightness to 0.5.*/
+ lcd.clear();
+ lcd.inverseMode();
+ lcd.setBrightness(0.5);
+
+ /**Initialise the accelerometer.*/
+ mma8452.init();
+ Acceleration acceleration;
+
+ /**When button is not pushed, main features of Gradienter will be run.*/
+ while(!pb) {
+
+ /**Read value of acceleration.*/
+ acceleration = mma8452.readValues();//read value of acceleration
+
+ float Ax=acceleration.x;
+ float Ay=acceleration.y;
+
+ /**Draw three circles and two lines.*/
+ lcd.drawCircle(41,24,23,0);
+ lcd.drawCircle(41,24,4,0);
+ lcd.drawCircle(41,24,13,0);
+ lcd.drawLine(41,3,41,45,1);
+ lcd.drawLine(20,24,62,24,1);
+ lcd.refresh();
+
+ /**Pixes will be displayed if acceleration values are within -0.4 and 0.4.*/
+ if (abs(Ax)<=0.4&&abs(Ay)<=0.4) {
+
+ float X=Ax/0.018;
+ float Y=Ay/0.018;
+
+ lcd.setPixel(42+X, 26-Y);
+ lcd.setPixel(41+X, 26-Y);
+ lcd.setPixel(40+X, 26-Y);
+ lcd.setPixel(43+X, 25-Y);
+ lcd.setPixel(42+X, 25-Y);
+ lcd.setPixel(41+X, 25-Y);
+ lcd.setPixel(40+X, 25-Y);
+ lcd.setPixel(39+X, 25-Y);
+ lcd.setPixel(43+X, 24-Y);
+ lcd.setPixel(42+X, 24-Y);
+ lcd.setPixel(41+X, 24-Y);
+ lcd.setPixel(40+X, 24-Y);
+ lcd.setPixel(39+X, 24-Y);
+ lcd.setPixel(43+X, 23-Y);
+ lcd.setPixel(42+X, 23-Y);
+ lcd.setPixel(41+X, 23-Y);
+ lcd.setPixel(40+X, 23-Y);
+ lcd.setPixel(39+X, 23-Y);
+ lcd.setPixel(42+X, 22-Y);
+ lcd.setPixel(41+X, 22-Y);
+ lcd.setPixel(40+X, 22-Y);
+ lcd.refresh();
+
+ /**Displayed pixes will be cleared after 0.2 second.*/
+ wait(0.2);
+
+ lcd.clearPixel(42+X, 26-Y);
+ lcd.clearPixel(41+X, 26-Y);
+ lcd.clearPixel(40+X, 26-Y);
+ lcd.clearPixel(43+X, 25-Y);
+ lcd.clearPixel(42+X, 25-Y);
+ lcd.clearPixel(41+X, 25-Y);
+ lcd.clearPixel(40+X, 25-Y);
+ lcd.clearPixel(39+X, 25-Y);
+ lcd.clearPixel(43+X, 24-Y);
+ lcd.clearPixel(42+X, 24-Y);
+ lcd.clearPixel(41+X, 24-Y);
+ lcd.clearPixel(40+X, 24-Y);
+ lcd.clearPixel(39+X, 24-Y);
+ lcd.clearPixel(43+X, 23-Y);
+ lcd.clearPixel(42+X, 23-Y);
+ lcd.clearPixel(41+X, 23-Y);
+ lcd.clearPixel(40+X, 23-Y);
+ lcd.clearPixel(39+X, 23-Y);
+ lcd.clearPixel(42+X, 22-Y);
+ lcd.clearPixel(41+X, 22-Y);
+ lcd.clearPixel(40+X, 22-Y);
+ lcd.refresh();
+ }
+
+ /**All LEDs will be turned on if acceleration values are within -0.05 and 0.05.*/
+ if (abs(Ax)<=0.05&&abs(Ay)<=0.05) {
+ ledA=1;
+ ledB=1;
+ ledC=1;
+ ledD=1;
+ }
+
+ /**All LEDs will be turned off if acceleration values go beyond this range.*/
+ else {
+ ledA=0;
+ ledB=0;
+ ledC=0;
+ ledD=0;
+ }
+ }
+}
+
+/**
+@brief Display the function name of Angle Meter for 1 second before calling it.
+*/
+void fun1()
+{
+ /**Initialise the LCD and set brightness to 0.8.*/
+ lcd.init();
+ lcd.normalMode();
+ lcd.setBrightness(0.8);
+ lcd.clear();
+
+ /**Display the function name of Angle Meter.*/
+ lcd.printString("Electronic",12,2);
+ lcd.printString("Angle Meter",10,3);
+
+ /**Turn LED A and LED C on.*/
+ ledA=1;
+ ledB=0;
+ ledC=1;
+ ledD=0;
+
+ /**Call function of Angle Meter after 1 second delay.*/
+ flipper.attach(&AngleMeter, 1.0);
+}
+
+/**
+@brief Display the function name of Gradienter for 1 second before calling it.
+*/
+void fun2()
+{
+ /**Turn off the buzzer.*/
+ buzzer = 0;
+
+ /**Initialise the LCD and set brightness to 0.8.*/
+ lcd.init();
+ lcd.normalMode();
+ lcd.setBrightness(0.8);
+ lcd.clear();
+
+ /**Display the function name of Gradienter.*/
+ lcd.printString("Electronic",12,2);
+ lcd.printString("Gradienter",12,3);
+
+ /**Turn LED B and LED D on.*/
+ ledA=0;
+ ledB=1;
+ ledC=0;
+ ledD=1;
+
+ /**Call function of Gradienter after 1 second delay.*/
+ flipper.attach(&Gradienter, 1.0);
+}
+
+/**
+@brief Power down the Ethernet interface to save power.
+@brief Acknowledgements to Michael Wei's code.
+*/
+void PHY_PowerDown()
+{
+ if (!Peripheral_GetStatus(LPC1768_PCONP_PCENET))
+ EMAC_Init(); //init EMAC if it is not already init'd
+
+ unsigned int regv;
+ regv = read_PHY(PHY_REG_BMCR);
+ write_PHY(PHY_REG_BMCR, regv | (1 << PHY_REG_BMCR_POWERDOWN));
+ regv = read_PHY(PHY_REG_BMCR);
+
+ //shouldn't need the EMAC now.
+ Peripheral_PowerDown(LPC1768_PCONP_PCENET);
+
+ //and turn off the PHY OSC
+ LPC_GPIO1->FIODIR |= 0x8000000;
+ LPC_GPIO1->FIOCLR = 0x8000000;
+}
+
+static void write_PHY (unsigned int PhyReg, unsigned short Value) {
+ /* Write a data 'Value' to PHY register 'PhyReg'. */
+ unsigned int tout;
+ /* Hardware MII Management for LPC176x devices. */
+ LPC_EMAC->MADR = DP83848C_DEF_ADR | PhyReg;
+ LPC_EMAC->MWTD = Value;
+
+ /* Wait utill operation completed */
+ for (tout = 0; tout < MII_WR_TOUT; tout++) {
+ if ((LPC_EMAC->MIND & MIND_BUSY) == 0) {
+ break;
+ }
+ }
+}
+
+static unsigned short read_PHY (unsigned int PhyReg) {
+ /* Read a PHY register 'PhyReg'. */
+ unsigned int tout, val;
+
+ LPC_EMAC->MADR = DP83848C_DEF_ADR | PhyReg;
+ LPC_EMAC->MCMD = MCMD_READ;
+
+ /* Wait until operation completed */
+ for (tout = 0; tout < MII_RD_TOUT; tout++) {
+ if ((LPC_EMAC->MIND & MIND_BUSY) == 0) {
+ break;
+ }
+ }
+ LPC_EMAC->MCMD = 0;
+ val = LPC_EMAC->MRDD;
+
+ return (val);
+}
+
+void EMAC_Init()
+{
+ unsigned int tout,regv;
+ /* Power Up the EMAC controller. */
+ Peripheral_PowerUp(LPC1768_PCONP_PCENET);
+
+ LPC_PINCON->PINSEL2 = 0x50150105;
+ LPC_PINCON->PINSEL3 &= ~0x0000000F;
+ LPC_PINCON->PINSEL3 |= 0x00000005;
+
+ /* Reset all EMAC internal modules. */
+ LPC_EMAC->MAC1 = MAC1_RES_TX | MAC1_RES_MCS_TX | MAC1_RES_RX | MAC1_RES_MCS_RX |
+ MAC1_SIM_RES | MAC1_SOFT_RES;
+ LPC_EMAC->Command = CR_REG_RES | CR_TX_RES | CR_RX_RES;
+
+ /* A short delay after reset. */
+ for (tout = 100; tout; tout--);
+
+ /* Initialize MAC control registers. */
+ LPC_EMAC->MAC1 = MAC1_PASS_ALL;
+ LPC_EMAC->MAC2 = MAC2_CRC_EN | MAC2_PAD_EN;
+ LPC_EMAC->MAXF = ETH_MAX_FLEN;
+ LPC_EMAC->CLRT = CLRT_DEF;
+ LPC_EMAC->IPGR = IPGR_DEF;
+
+ /* Enable Reduced MII interface. */
+ LPC_EMAC->Command = CR_RMII | CR_PASS_RUNT_FRM;
+
+ /* Reset Reduced MII Logic. */
+ LPC_EMAC->SUPP = SUPP_RES_RMII;
+ for (tout = 100; tout; tout--);
+ LPC_EMAC->SUPP = 0;
+
+ /* Put the DP83848C in reset mode */
+ write_PHY (PHY_REG_BMCR, 0x8000);
+
+ /* Wait for hardware reset to end. */
+ for (tout = 0; tout < 0x100000; tout++) {
+ regv = read_PHY (PHY_REG_BMCR);
+ if (!(regv & 0x8000)) {
+ /* Reset complete */
+ break;
+ }
+ }
+}
+
+/**
+@brief Functions used to display characters and shapes.
+@brief Acknowledgements to Dr.Craig A. Evans's code.
+*/
+N5110::N5110(PinName pwrPin, PinName scePin, PinName rstPin, PinName dcPin, PinName mosiPin, PinName sclkPin, PinName ledPin)
+{
+
+ spi = new SPI(mosiPin,NC,sclkPin); // create new SPI instance and initialise
+ initSPI();
+
+ // set up pins as required
+ led = new PwmOut(ledPin);
+ pwr = new DigitalOut(pwrPin);
+ sce = new DigitalOut(scePin);
+ rst = new DigitalOut(rstPin);
+ dc = new DigitalOut(dcPin);
+
+}
+
+// initialise function - powers up and sends the initialisation commands
+void N5110::init()
+{
+ turnOn(); // power up
+ wait_ms(10); // small delay seems to prevent spurious pixels during mbed reset
+ reset(); // reset LCD - must be done within 100 ms
+
+ // function set - extended
+ sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);
+ // Don't completely understand these parameters - they seem to work as they are
+ // Consult the datasheet if you need to change them
+ sendCommand(CMD_VOP_7V38); // operating voltage - these values are from Chris Yan's Library
+ sendCommand(CMD_TC_TEMP_2); // temperature control
+ sendCommand(CMD_BI_MUX_48); // bias
+
+ // function set - basic
+ sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);
+ normalMode(); // normal video mode by default
+ sendCommand(CMD_DC_NORMAL_MODE); // black on white
+
+ // RAM is undefined at power-up so clear
+ clearRAM();
+
+}
+
+// sets normal video mode (black on white)
+void N5110::normalMode()
+{
+ sendCommand(CMD_DC_NORMAL_MODE);
+
+}
+
+// sets normal video mode (white on black)
+void N5110::inverseMode()
+{
+ sendCommand(CMD_DC_INVERT_VIDEO);
+}
+
+// function to power up the LCD and backlight
+void N5110::turnOn()
+{
+ // set brightness of LED - 0.0 to 1.0 - default is 50%
+ setBrightness(0.5);
+ pwr->write(1); // apply power
+}
+
+// function to power down LCD
+void N5110::turnOff()
+{
+ setBrightness(0.0); // turn backlight off
+ clearRAM(); // clear RAM to ensure specified current consumption
+ // send command to ensure we are in basic mode
+ sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);
+ // clear the display
+ sendCommand(CMD_DC_CLEAR_DISPLAY);
+ // enter the extended mode and power down
+ sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);
+ // small delay and then turn off the power pin
+ wait_ms(10);
+ pwr->write(0);
+
+}
+
+// function to change LED backlight brightness
+void N5110::setBrightness(float brightness)
+{
+ // check whether brightness is within range
+ if (brightness < 0.0)
+ brightness = 0.0;
+ if (brightness > 1.0)
+ brightness = 1.0;
+ // set PWM duty cycle
+ led->write(brightness);
+}
+
+// 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)
+
+}
+
+// this function writes 0 to the 504 bytes to clear the RAM
+void N5110::clearRAM()
+{
+ int i;
+ sce->write(0); //set CE low to begin frame
+ for(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(int x, int y)
+{
+ if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range
+ sendCommand(0x80 | x); // send addresses to display with relevant mask
+ sendCommand(0x40 | 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(int x, int y)
+{
+ if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range
+ // calculate bank and shift 1 to required position in the data byte
+ buffer[x][y/8] |= (1 << y%8);
+ }
+}
+
+void N5110::clearPixel(int x, int y)
+{
+ if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range
+ // calculate bank and shift 1 to required position (using bit clear)
+ buffer[x][y/8] &= ~(1 << y%8);
+ }
+}
+
+// function to refresh the display
+void N5110::refresh()
+{
+ int i,j;
+
+ 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(j = 0; j < BANKS; j++) { // be careful to use correct order (j,i) for horizontal addressing
+ for(i = 0; i < WIDTH; i++) {
+ spi->write(buffer[i][j]); // send buffer
+ }
+ }
+ sce->write(1); // set CE high to end frame
+
+}
+
+// function to print string at specified position
+void N5110::printString(const char * str,int x,int y)
+{
+ if (y>=0 && 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
+
+ }
+
+ refresh(); // this sends the buffer to the display and sets address (cursor) back to 0,0
+ }
+}
+
+// function to clear the screen
+void N5110::clear()
+{
+ clearBuffer(); // clear the buffer then call the refresh function
+ refresh();
+}
+
+// function to clear the buffer
+void N5110::clearBuffer()
+{
+ int i,j;
+ for (i=0; i<WIDTH; i++) { // loop through the banks and set the buffer to 0
+ for (j=0; j<BANKS; j++) {
+ buffer[i][j]=0;
+ }
+ }
+}
+
+// function to draw circle
+void N5110:: drawCircle(int x0,int y0,int radius,int 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 == 0) {
+ setPixel( x + x0, y + y0);
+ setPixel(-x + x0, y + y0);
+ setPixel( y + x0, x + y0);
+ setPixel(-y + x0, x + y0);
+ setPixel(-y + x0, -x + y0);
+ setPixel( y + x0, -x + y0);
+ setPixel( x + x0, -y + y0);
+ setPixel(-x + x0, -y + y0);
+ } else { // drawing filled circle, so draw lines between points at same y value
+
+ int type = (fill==1) ? 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(int x0,int y0,int x1,int y1,int type)
+{
+ int y_range = y1-y0; // calc range of y and x
+ int x_range = x1-x0;
+ int start,stop,step;
+
+ // if dotted line, set step to 2, else step is 1
+ 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
+ start = x1>x0 ? x0:x1;
+ stop = x1>x0 ? x1:x0;
+
+ // loop between x pixels
+ for (int x = start; x<= stop ; x+=step) {
+ // do linear interpolation
+ int y = y0 + (y1-y0)*(x-x0)/(x1-x0);
+
+ if (type == 0) // if 'white' line, turn off pixel
+ clearPixel(x,y);
+ else
+ setPixel(x,y); // else if 'black' or 'dotted' turn on pixel
+ }
+ } else {
+
+ // ensure we loop from smallest to largest or else for-loop won't run as expected
+ start = y1>y0 ? y0:y1;
+ stop = y1>y0 ? y1:y0;
+
+ for (int y = start; y<= stop ; y+=step) {
+ // do linear interpolation
+ int x = x0 + (x1-x0)*(y-y0)/(y1-y0);
+
+ if (type == 0) // if 'white' line, turn off pixel
+ clearPixel(x,y);
+ else
+ setPixel(x,y); // else if 'black' or 'dotted' turn on pixel
+
+ }
+ }
+
+}
+
+MMA8452:: MMA8452(PinName sdaPin, PinName sclPin)
+{
+ i2c = new I2C(sdaPin,sclPin); // create new I2C instance and initialise
+ i2c->frequency(400000); // I2C Fast Mode - 400kHz
+ leds = new BusOut(LED4,LED3,LED2,LED1); // for debug
+}
+
+void MMA8452::init()
+{
+
+ i2c->frequency(400000); // set Fast Mode I2C frequency (5.10 datasheet)
+
+ char data = readByteFromRegister(WHO_AM_I); // p18 datasheet
+ if (data != 0x2A) { // if correct ID not found, hand and flash error message
+ error();
+ }
+
+ // put into STANDBY while configuring
+ data = readByteFromRegister(CTRL_REG1); // get current value of register
+ data &= ~(1<<0); // clear bit 0 (p37 datasheet)
+ sendByteToRegister(data,CTRL_REG1);
+
+ // Set output data rate, default is 800 Hz, will set to 100 Hz (clear b5, set b4/b3 - p37 datasheet)
+ data = readByteFromRegister(CTRL_REG1);
+ data &= ~(1<<5);
+ data |= (1<<4);
+ data |= (1<<3);
+ sendByteToRegister(data,CTRL_REG1);
+
+ //// Can also change default 2g range to 4g or 8g (p22 datasheet)
+ data = readByteFromRegister(XYZ_DATA_CFG);
+ data |= (1<<0); // set bit 0 - 4g range
+ sendByteToRegister(data,XYZ_DATA_CFG);
+
+ // set ACTIVE
+ data = readByteFromRegister(CTRL_REG1);
+ data |= (1<<0); // set bit 0 in CTRL_REG1
+ sendByteToRegister(data,CTRL_REG1);
+
+}
+
+// read acceleration data from device
+Acceleration MMA8452::readValues()
+{
+ // acceleration data stored in 6 registers (0x01 to 0x06)
+ // device automatically increments register, so can read 6 bytes starting from OUT_X_MSB
+ char data[6];
+ readBytesFromRegister(OUT_X_MSB,6,data);
+
+ char x_MSB = data[0]; // extract MSB and LSBs for x,y,z values
+ char x_LSB = data[1];
+ char y_MSB = data[2];
+ char y_LSB = data[3];
+ char z_MSB = data[4];
+ char z_LSB = data[5];
+
+ // [0:7] of MSB are 8 MSB of 12-bit value , [7:4] of LSB are 4 LSB's of 12-bit value
+ // need to type-cast as numbers are in signed (2's complement) form (p20 datasheet)
+ int x = (int16_t) (x_MSB << 8) | x_LSB; // combine bytes
+ x >>= 4; // are left-aligned, so shift 4 places right to right-align
+ int y = (int16_t) (y_MSB << 8) | y_LSB;
+ y >>= 4;
+ int z = (int16_t) (z_MSB << 8) | z_LSB;
+ z >>= 4;
+
+ // sensitivity is 1024 counts/g in 2g mode (pg 9 datasheet)
+ // " " 512 " 4g "
+ // " " 256 " 8g "
+ Acceleration acc;
+
+ acc.x = x/512.0;
+ acc.y = y/512.0;
+ acc.z = z/512.0;
+
+ return acc;
+}
+
+// reads a byte from a specific register
+char MMA8452::readByteFromRegister(char reg)
+{
+ int nack = i2c->write(MMA8452_W_ADDRESS,®,1,true); // send the register address to the slave
+ // true as need to send repeated start condition (5.10.1 datasheet)
+ // http://www.i2c-bus.org/repeated-start-condition/
+ if (nack)
+ error(); // if we don't receive acknowledgement, flash error message
+
+ char rx;
+ nack = i2c->read(MMA8452_R_ADDRESS,&rx,1); // read a byte from the register and store in buffer
+ if (nack)
+ error(); // if we don't receive acknowledgement, flash error message
+
+ return rx;
+}
+
+// reads a series of bytes, starting from a specific register
+void MMA8452::readBytesFromRegister(char reg,int numberOfBytes,char bytes[])
+{
+
+ int nack = i2c->write(MMA8452_W_ADDRESS,®,1,true); // send the slave write address and the configuration register address
+ // true as need to send repeated start condition (5.10.1 datasheet)
+ // http://www.i2c-bus.org/repeated-start-condition/
+
+ if (nack)
+ error(); // if we don't receive acknowledgement, flash error message
+
+ nack = i2c->read(MMA8452_R_ADDRESS,bytes,numberOfBytes); // read bytes
+ if (nack)
+ error(); // if we don't receive acknowledgement, flash error message
+
+}
+
+// sends a byte to a specific register
+void MMA8452::sendByteToRegister(char byte,char reg)
+{
+ char data[2];
+ data[0] = reg;
+ data[1] = byte;
+ // send the register address, followed by the data
+ int nack = i2c->write(MMA8452_W_ADDRESS,data,2);
+ if (nack)
+ error(); // if we don't receive acknowledgement, flash error message
+
+}
+
+void MMA8452::error()
+{
+ while(1) {
+ leds->write(15);
+ wait(0.1);
+ leds->write(0);
+ wait(0.1);
+ }
+}
+
+
+
+