Shang Tianting
Accelerometer and angle meter
Diff: main.cpp
- Revision:
- 0:a57e07e44ab0
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun May 10 00:23:23 2015 +0000
@@ -0,0 +1,696 @@
+/**
+@file N5110.cpp
+
+@brief Member functions implementations
+
+*/
+#include "mbed.h"
+#include "N5110.h"
+#include "MMA8452.h"
+#include "Beep.h"
+
+
+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)
+
+}
+
+// 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()
+{
+ 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);
+ }
+}
+
+int N5110::getPixel(int x, int y)
+{
+ if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) { // check within range
+ // return relevant bank and mask required bit
+ return (int) buffer[x][y/8] & (1 << y%8);
+ // note this does not necessarily return 1 - a non-zero number represents a pixel
+ } else {
+ return 0;
+ }
+}
+
+// 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
+
+}
+
+// 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 c,int x,int y)
+{
+ if (y>=0 && 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
+ }
+
+ refresh(); // this sends the buffer to the display and sets address (cursor) back to 0,0
+ }
+}
+
+// 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 plot array on display
+void N5110::plotArray(float array[])
+{
+
+ int i;
+
+ for (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]*47.0));
+ }
+
+ refresh();
+
+}
+
+// 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
+
+ }
+ }
+
+}
+
+void N5110::drawRect(int x0,int y0,int width,int height,int fill)
+{
+
+ if (fill == 0) { // transparent, just outline
+ drawLine(x0,y0,x0+width,y0,1); // top
+ drawLine(x0,y0+height,x0+width,y0+height,1); // bottom
+ drawLine(x0,y0,x0,y0+height,1); // left
+ drawLine(x0+width,y0,x0+width,y0+height,1); // right
+ } else { // filled rectangle
+ int type = (fill==1) ? 1:0; // black or white fill
+ for (int y = y0; y<= y0+height; y++) { // loop through rows of rectangle
+ drawLine(x0,y,x0+width,y,type); // draw line across screen
+ }
+ }
+
+}
+
+
+
+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);
+ }
+}
+
+
+
+
+
+
+
+
+
+
+
+N5110 lcd(p7,p8,p9,p10,p11,p13,p26);
+MMA8452 mma8452(p28,p27); // SDA, SCL
+Serial serial(USBTX,USBRX);
+DigitalOut myLED1(p24);
+InterruptIn button(p29);
+Beep buzzer(p21);
+BusOut leds (LED4,LED3,LED2,LED1);
+
+int fsm[5]={1,3,8,12,0};//array for led in mbed
+int state=0;
+int buttonFlag=0;//button
+
+void buttonPressed(){
+ buttonFlag=1;
+ }
+
+
+int main()
+{
+ // first need to initialise display and MMA8452
+
+ lcd.init();
+ mma8452.init();// 100 Hz update rate, ±4g scale
+
+
+ lcd.normalMode();
+
+ //rise up button
+ button.rise(&buttonPressed);
+
+ //show initial interface
+ lcd.printString("Acceleration",4,1);
+ lcd.printString("And Angle",4,2);
+ lcd.printString("Measurer",4,3);
+ lcd.drawRect(2,2,78,43,0); // transparent, just outline
+ lcd.refresh(); // need to refresh screen after drawing rects
+
+
+ wait(2.0);
+ lcd.clear();
+
+ Acceleration acceleration; // Accleration structure declared in MMA8452 class
+
+
+ while(1) {
+
+
+
+ lcd.printString("Acceleration:",0,0);
+ lcd.printString("Angle:",0,4);
+
+ myLED1 = 0;
+
+ acceleration = mma8452.readValues(); // read current values and print over serial port
+
+
+
+ //show acceleration x,y,z
+ char x[14];
+ int length=sprintf(x,"x = %.2f g",acceleration.x);
+ if (length <= 14)
+ lcd.printString(x,0,1);
+
+ char y[14];
+ int length2=sprintf(y,"y = %.2f g",acceleration.y);
+ if (length2 <= 14)
+ lcd.printString(y,0,2);
+
+ char z[14];
+ int length3=sprintf(z,"z = %.2f g",acceleration.z);
+ if (length3 <= 14)
+ lcd.printString(z,0,3);
+
+ //convert acceration in z to angle
+ char angleZ[14];
+ float anglez=90-(acceleration.z/1*90);
+
+
+
+ // set button
+ if (buttonFlag){
+ buttonFlag=0;
+ int angle3=sprintf(angleZ,"%.2f",anglez);
+ lcd.printString(angleZ,0,5);
+ }
+
+
+
+ if (anglez>=30){
+
+ myLED1 = 1;
+
+ }
+
+
+
+ if(anglez>=30&&acceleration.x>0){
+
+ leds=fsm[0];
+
+ }
+
+
+ if(anglez>=60&&acceleration.x>0){
+ leds=fsm[1];
+
+ }
+
+
+ if(anglez>=30&&acceleration.x<0){
+
+ leds=fsm[2];
+ }
+
+
+ if(anglez>=60&&acceleration.x<0){
+ leds=fsm[3];
+ }
+
+
+ if(anglez<30){
+ leds=fsm[4];
+ }
+
+
+ if(anglez>=60){
+
+ buzzer.beep(2000,0.5);
+ }
+
+
+
+ wait(0.1);
+ lcd.refresh();
+
+
+
+ }
+
+
+ }
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