The Accelerometer and Slope program

Dependencies:   MMA8452 PowerControl mbed

Revision:
0:7f98d386be37
diff -r 000000000000 -r 7f98d386be37 N5110.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110.cpp	Mon May 11 21:18:42 2015 +0000
@@ -0,0 +1,551 @@
+/**
+@file N5110.cpp
+
+@brief Member functions implementations
+@brief The fundamental code of a Accelerometer and SpiritLevel
+@brief SpiritLevel 1.0
+@author Bo Xu
+@date  May 2015
+*/
+#include "mbed.h"
+#include "N5110.h"
+#include "MMA8452.h"
+#include "PowerControl/PowerControl.h"
+#include "PowerControl/EthernetPowerControl.h"
+
+#define USR_POWERDOWN  (0x104)
+
+/**
+@namespace button
+@brief AnalogIn for application button
+*/
+InterruptIn button(p16);
+
+#define accelerator 0
+#define slope 1
+
+int function = accelerator;
+/**
+namespace led
+@brief Pwmout for SpiritLevel LED
+*/
+PwmOut led(p24);
+
+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);
+
+}
+
+/**
+initialize the N5110 and declare the pins it connected to the microcontroller
+*/
+N5110 lcd(p7, p8, p9, p10, p11, p13, p26);
+/**
+initialize the MMA8452 sensor and declare the pins it connected to the microcontroller
+*/
+MMA8452 mma8452(p28, p27);
+
+Serial serial (USBTX, USBRX);
+
+int semihost_powerdown() {
+    uint32_t arg;
+    return __semihost(USR_POWERDOWN, &arg);
+}
+
+// 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 for the function button
+*/
+void buttonPressed(){
+    
+    function = !function;
+        
+}
+        
+// function to power up the LCD and backlight
+void N5110::turnOn()
+{
+    // set brightness of LED - 0.0 to 1.0 - default is 50%
+    setBrightness( 0.2);
+    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
+        }
+    }
+
+}
+    
+    
+
+int main(){
+    /**
+    Power down the Ethernet in order to save power
+    */
+    semihost_powerdown();
+    
+    PHY_PowerDown();
+    /**
+    initialize the LCD display and MMA8452 sensor
+    */
+    lcd.init();
+    mma8452.init();
+    
+    Acceleration acceleration;
+    
+        wait(.001);
+    
+    button.rise(&buttonPressed);
+    
+    
+    while (1){
+        /**
+        Read values from the MMA8452 sensor
+        */
+        acceleration = mma8452.readValues();
+        
+        /**
+        state two different applications of the device
+        function=0 - Accelerometer
+        function=1 - Slope
+        */
+        switch(function){
+            case accelerator:  
+                      
+            /**
+            the algorithm of the acceleration
+            */
+            char buffer[14];
+            int length = sprintf(buffer,"Acceleration");
+            char buffer2[14];
+            length = sprintf(buffer2,"x = %.2f g", acceleration.x);
+            char buffer3[14];
+            length = sprintf(buffer3,"y = %.2f g", acceleration.y);
+            char buffer4[14];
+            length = sprintf(buffer4,"z = %.2f g", acceleration.z);
+            /**
+            draw a rectangle and print the acceleration
+            */
+            lcd.drawRect(0,0,83,47,0);
+                lcd.printString(buffer,4,1);
+                lcd.printString(buffer2,4,2);
+                lcd.printString(buffer3,4,3);
+                lcd.printString(buffer4,4,4);
+                wait(0.1);
+                lcd.clear();
+            break;
+            
+            case slope:
+                /**
+                algorithm to calculate the angle
+                */
+                char buffer5[14];
+                length = sprintf(buffer5, "Slope");
+                char buffer6[14];
+                length = sprintf(buffer6, "x =%.2f pi", asin(acceleration.x)/3.1415926);
+                char buffer7[14];
+                length = sprintf(buffer7, "y =%.2f pi", asin(acceleration.y)/3.1415926);
+                /**
+                draw rectangle and print the data
+                */
+                lcd.drawRect(0,0,83,47,0);
+                    lcd.printString(buffer5,3,1);
+                    lcd.printString(buffer6,3,2);
+                    lcd.printString(buffer7,3,3);
+                    wait(0.1);
+                    lcd.clear();
+                    
+                /**
+                determine if the device is perfect level
+                when the acceleration on z-axis is greater than 0.95
+                the LED will be turned on
+                */    
+                if (acceleration.z > 0.95){
+                    led.write(1);
+                    }else
+                    led.write(0);
+                    
+               break; 
+            
+            }
+            
+        }
+        
+}
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