Line follower and object avoider

Dependencies:   mbed SHARPIR

Files at this revision

API Documentation at this revision

Comitter:
nepol77
Date:
Thu Apr 12 14:37:54 2012 +0000
Commit message:
Hi guys, i will put the pictures on very soon!! Thanks for looking

Changed in this revision

m3pi/m3pi.cpp Show annotated file Show diff for this revision Revisions of this file
m3pi/m3pi.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
sharp_pid.lib Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r df7d60d7a6ee m3pi/m3pi.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m3pi/m3pi.cpp	Thu Apr 12 14:37:54 2012 +0000
@@ -0,0 +1,234 @@
+/* m3pi Library
+ *
+ * Copyright (c) 2007-2010 cstyles
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "mbed.h"
+#include "m3pi.h"
+
+m3pi::m3pi(PinName nrst, PinName tx, PinName rx) :  Stream("m3pi"), _nrst(nrst), _ser(tx, rx)  {
+    _ser.baud(115200);
+    reset();
+}
+
+m3pi::m3pi() :  Stream("m3pi"), _nrst(p23), _ser(p9, p10)  {
+    _ser.baud(115200);
+    reset();
+}
+
+
+void m3pi::reset () {
+    _nrst = 0;
+    wait (0.01);
+    _nrst = 1;
+    wait (0.1);
+}
+
+void m3pi::left_motor (float speed) {
+    motor(0,speed);
+}
+
+void m3pi::right_motor (float speed) {
+    motor(1,speed);
+}
+
+void m3pi::forward (float speed) {
+    motor(0,speed);
+    motor(1,speed);
+}
+
+void m3pi::backward (float speed) {
+    motor(0,-1.0*speed);
+    motor(1,-1.0*speed);
+}
+
+void m3pi::left (float speed) {
+    motor(0,speed);
+    motor(1,-1.0*speed);
+}
+
+void m3pi::right (float speed) {
+    motor(0,-1.0*speed);
+    motor(1,speed);
+}
+
+void m3pi::stop (void) {
+    motor(0,0.0);
+    motor(1,0.0);
+}
+
+void m3pi::motor (int motor, float speed) {
+    char opcode = 0x0;
+    if (speed > 0.0) {
+        if (motor==1)
+            opcode = M1_FORWARD;
+        else
+            opcode = M2_FORWARD;
+    } else {
+        if (motor==1)
+            opcode = M1_BACKWARD;
+        else
+            opcode = M2_BACKWARD;
+    }
+    unsigned char arg = 0x7f * abs(speed);
+
+    _ser.putc(opcode);
+    _ser.putc(arg);
+}
+
+float m3pi::battery() {
+    _ser.putc(SEND_BATTERY_MILLIVOLTS);
+    char lowbyte = _ser.getc();
+    char hibyte  = _ser.getc();
+    float v = ((lowbyte + (hibyte << 8))/1000.0);
+    return(v);
+}
+
+float m3pi::line_position() {
+    int pos = 0;
+    _ser.putc(SEND_LINE_POSITION);
+    pos = _ser.getc();
+    pos += _ser.getc() << 8;
+    
+    float fpos = ((float)pos - 2048.0)/2048.0;
+    return(fpos);
+}
+
+char m3pi::sensor_auto_calibrate() {
+    _ser.putc(AUTO_CALIBRATE);
+    return(_ser.getc());
+}
+
+
+void m3pi::calibrate(void) {
+    _ser.putc(PI_CALIBRATE);
+}
+
+void m3pi::reset_calibration() {
+    _ser.putc(LINE_SENSORS_RESET_CALIBRATION);
+}
+
+void m3pi::PID_start(int max_speed, int a, int b, int c, int d) {
+    _ser.putc(max_speed);
+    _ser.putc(a);
+    _ser.putc(b);
+    _ser.putc(c);
+    _ser.putc(d);
+}
+
+void m3pi::PID_stop() {
+    _ser.putc(STOP_PID);
+}
+
+float m3pi::pot_voltage(void) {
+    int volt = 0;
+    _ser.putc(SEND_TRIMPOT);
+    volt = _ser.getc();
+    volt += _ser.getc() << 8;
+    return(volt);
+}
+
+
+void m3pi::leds(int val) {
+
+    BusOut _leds(p20,p19,p18,p17,p16,p15,p14,p13);
+    _leds = val;
+}
+
+
+void m3pi::locate(int x, int y) {
+    _ser.putc(DO_LCD_GOTO_XY);
+    _ser.putc(x);
+    _ser.putc(y);
+}
+
+void m3pi::cls(void) {
+    _ser.putc(DO_CLEAR);
+}
+
+int m3pi::print (char* text, int length) {
+    _ser.putc(DO_PRINT);  
+    _ser.putc(length);       
+    for (int i = 0 ; i < length ; i++) {
+        _ser.putc(text[i]); 
+    }
+    return(0);
+}
+
+int m3pi::_putc (int c) {
+    _ser.putc(DO_PRINT);  
+    _ser.putc(0x1);       
+    _ser.putc(c);         
+    wait (0.001);
+    return(c);
+}
+
+int m3pi::_getc (void) {
+    char r = 0;
+    return(r);
+}
+
+int m3pi::putc (int c) {
+    return(_ser.putc(c));
+}
+
+int m3pi::getc (void) {
+    return(_ser.getc());
+}
+
+
+void m3pi::readsensor (int *sensor){
+   
+   _ser.putc(SEND_CALIBRATED_SENSOR_VALUES);  
+    sensor[0] = _ser.getc();
+    sensor[0] += _ser.getc() << 8;
+    sensor[1] = _ser.getc();
+    sensor[1] += _ser.getc() << 8;
+    sensor[2] = _ser.getc();
+    sensor[2] += _ser.getc() << 8;
+    sensor[3] = _ser.getc();
+    sensor[3] += _ser.getc() << 8;
+    sensor[4] = _ser.getc();
+    sensor[4] += _ser.getc() << 8;
+  
+    return;
+}
+
+
+#ifdef MBED_RPC
+const rpc_method *m3pi::get_rpc_methods() {
+    static const rpc_method rpc_methods[] = {{ "forward", rpc_method_caller<m3pi, float, &m3pi::forward> },
+        { "backward", rpc_method_caller<m3pi, float, &m3pi::backward> },
+        { "left", rpc_method_caller<m3pi, float, &m3pi::left> },
+        { "right", rpc_method_caller<m3pi, float, &m3pi::right> },
+        { "stop", rpc_method_caller<m3pi, &m3pi::stop> },
+        { "left_motor", rpc_method_caller<m3pi, float, &m3pi::left_motor> },
+        { "right_motor", rpc_method_caller<m3pi, float, &m3pi::right_motor> },
+        { "battery", rpc_method_caller<float, m3pi, &m3pi::battery> },
+        { "line_position", rpc_method_caller<float, m3pi, &m3pi::line_position> },
+        { "sensor_auto_calibrate", rpc_method_caller<char, m3pi, &m3pi::sensor_auto_calibrate> },
+
+
+        RPC_METHOD_SUPER(Base)
+    };
+    return rpc_methods;
+}
+#endif
diff -r 000000000000 -r df7d60d7a6ee m3pi/m3pi.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m3pi/m3pi.h	Thu Apr 12 14:37:54 2012 +0000
@@ -0,0 +1,244 @@
+/* mbed m3pi Library
+ * Copyright (c) 2007-2010 cstyles
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef M3PI_H
+#define M3PI_H
+
+#include "mbed.h"
+#include "platform.h"
+
+#ifdef MBED_RPC
+#include "rpc.h"
+#endif
+
+#define SEND_CALIBRATED_SENSOR_VALUES 0x87
+#define SEND_SIGNATURE 0x81
+#define SEND_RAW_SENSOR_VALUES 0x86
+#define SEND_TRIMPOT 0xB0
+#define SEND_BATTERY_MILLIVOLTS 0xB1
+#define DO_PLAY 0xB3
+#define PI_CALIBRATE 0xB4
+#define DO_CLEAR 0xB7
+#define DO_PRINT 0xB8
+#define DO_LCD_GOTO_XY 0xB9
+#define LINE_SENSORS_RESET_CALIBRATION 0xB5
+#define SEND_LINE_POSITION 0xB6
+#define AUTO_CALIBRATE 0xBA
+#define SET_PID 0xBB
+#define STOP_PID 0xBC
+#define M1_FORWARD 0xC1
+#define M1_BACKWARD 0xC2
+#define M2_FORWARD 0xC5
+#define M2_BACKWARD 0xC6
+
+
+
+/** m3pi control class
+ *
+ * Example:
+ * @code
+ * // Drive the m3pi forward, turn left, back, turn right, at half speed for half a second
+
+   #include "mbed.h"
+   #include "m3pi.h"
+
+   m3pi pi;
+
+   int main() {
+
+     wait(0.5);
+
+     pi.forward(0.5);
+     wait (0.5);
+     pi.left(0.5);
+     wait (0.5);
+     pi.backward(0.5);
+     wait (0.5);
+     pi.right(0.5);
+     wait (0.5);
+
+     pi.stop();
+
+ }
+ * @endcode
+ */
+class m3pi :  public Stream {
+
+    // Public functions
+public:
+
+    /** Create the m3pi object connected to the default pins
+     *
+     * @param nrst GPIO pin used for reset. Default is p23
+     * @param tx Serial transmit pin. Default is p9
+     * @param rx Serial receive pin. Default is p10
+     */
+    m3pi();
+
+
+    /** Create the m3pi object connected to the default pins
+     *
+     */
+    m3pi(PinName nrst, PinName tx, PinName rx);
+
+
+
+    /** Force a hardware reset of the 3pi
+     */
+    void reset (void);
+
+    /** Directly control the speed and direction of the left motor
+     *
+     * @param speed A normalised number -1.0 - 1.0 represents the full range.
+     */
+    void left_motor (float speed);
+
+    /** Directly control the speed and direction of the right motor
+     *
+     * @param speed A normalised number -1.0 - 1.0 represents the full range.
+     */
+    void right_motor (float speed);
+
+    /** Drive both motors forward as the same speed
+     *
+     * @param speed A normalised number 0 - 1.0 represents the full range.
+     */
+    void forward (float speed);
+
+    /** Drive both motors backward as the same speed
+     *
+     * @param speed A normalised number 0 - 1.0 represents the full range.
+     */
+    void backward (float speed);
+
+    /** Drive left motor backwards and right motor forwards at the same speed to turn on the spot
+     *
+     * @param speed A normalised number 0 - 1.0 represents the full range.
+     */
+    void left (float speed);
+
+    /** Drive left motor forward and right motor backwards at the same speed to turn on the spot
+     * @param speed A normalised number 0 - 1.0 represents the full range.
+     */
+    void right (float speed);
+
+    /** Stop both motors
+     *
+     */
+    void stop (void);
+
+    /** Read the voltage of the potentiometer on the 3pi
+     * @returns voltage as a float
+     *
+     */
+    float pot_voltage(void);
+
+    /** Read the battery voltage on the 3pi
+     * @returns battery voltage as a float
+     */
+    float battery(void);
+
+    /** Read the position of the detected line
+     * @returns position as A normalised number -1.0 - 1.0 represents the full range.
+     *  -1.0 means line is on the left, or the line has been lost
+     *   0.0 means the line is in the middle
+     *   1.0 means the line is on the right
+     */
+    float line_position (void);
+
+
+    /** Calibrate the sensors. This turns the robot left then right, looking for a line
+     *
+     */
+    char sensor_auto_calibrate (void);
+
+    /** Set calibration manually to the current settings.
+     *
+     */
+    void calibrate(void);
+
+    /** Clear the current calibration settings
+     *
+     */
+    void reset_calibration (void);
+
+    void PID_start(int max_speed, int a, int b, int c, int d);
+
+    void PID_stop();
+
+    /** Write to the 8 LEDs
+     *
+     * @param leds An 8 bit value to put on the LEDs
+     */
+    void leds(int val);
+
+    /** Locate the cursor on the 8x2 LCD
+     *
+     * @param x The horizontal position, from 0 to 7
+     * @param y The vertical position, from 0 to 1
+     */
+    void locate(int x, int y);
+
+    /** Clear the LCD
+     *
+     */
+    void cls(void);
+
+    /** Send a character directly to the 3pi serial interface
+     * @param c The character to send to the 3pi
+     */
+    int putc(int c);
+
+    /** Receive a character directly to the 3pi serial interface
+     * @returns c The character received from the 3pi
+     */
+    int getc();
+
+    /** Send a string buffer to the 3pi serial interface
+     * @param text A pointer to a char array
+     * @param int The character to send to the 3pi
+     */
+    int print(char* text, int length);
+    
+    /**
+    * Read the calibrated value of a sensor
+    * @param sensor Pointer to array sensor [0-4]
+    * @param values returned in the range 0-1000 where 1000=completely dark
+    */
+    void readsensor(int *sensor);
+    
+#ifdef MBED_RPC
+    virtual const struct rpc_method *get_rpc_methods();
+#endif
+
+private :
+
+    DigitalOut _nrst;
+    Serial _ser;
+    
+    void motor (int motor, float speed);
+    virtual int _putc(int c);
+    virtual int _getc();
+
+};
+
+#endif
\ No newline at end of file
diff -r 000000000000 -r df7d60d7a6ee main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Apr 12 14:37:54 2012 +0000
@@ -0,0 +1,336 @@
+#include "mbed.h"
+#include "m3pi.h"
+AnalogIn sensor(p20);
+BusOut leds(LED1,LED2,LED3,LED4);
+m3pi m3pi(p23,p9,p10);
+
+#define MAX 0.5
+#define MIN 0
+
+
+#define P_TERM 1
+#define I_TERM 0
+#define D_TERM 20
+
+// Global variables
+// The path array stores the route info. Each element shows what we did at an intersection
+
+//  'L' for left
+//  'R' for right
+//  'F' for forward
+//  'B' for back 
+//
+char path[1000] = "";
+unsigned char path_length = 0; // the length of the path so far
+ 
+
+void follow_line()
+{
+    float right;
+    float left;
+    float position_of_line = 0.0;
+    float prev_pos_of_line = 0.0;
+    float derivative,proportional;
+    float integral = 0;
+    float power;
+    float speed = MAX;
+    int foundjunction=0;
+    int countdown=150; //make sure we don't stop for a junction too soon after starting
+   int DistanceCM;
+    
+    int sensors[5];    
+    while (foundjunction==0) {
+            DistanceCM =(pow( 1429.4/(sensor), 1.2134))/1000;
+
+            if (DistanceCM == 20)
+            {m3pi.right(0.25);wait(0.60);}
+            
+        // Get the position of the line.
+        position_of_line = m3pi.line_position();
+        proportional = position_of_line;
+        // Compute the derivative
+        derivative = position_of_line - prev_pos_of_line;
+        // Compute the integral
+        integral += proportional;
+         // Remember the last position.
+        prev_pos_of_line = position_of_line;
+        // Compute
+        power = (proportional * (P_TERM) ) + (integral*(I_TERM)) + (derivative*(D_TERM)) ;
+        
+        //    Compute new speeds   
+        right = speed+power;
+        left  = speed-power;
+        // limit checks
+        if (right < MIN)
+            right = MIN;
+        else if (right > MAX)
+            right = MAX;
+            
+        if (left < MIN)
+            left = MIN;
+        else if (left > MAX)
+            left = MAX;
+            
+       // set speed 
+        m3pi.left_motor(left);
+        m3pi.right_motor(right);
+
+    if (countdown>0) countdown--; else {
+       // Next, we are going to use the sensors to look for whether there is still a line ahead
+       // and try to detect dead ends and possible left or right turns.
+       m3pi.readsensor(sensors);
+      
+        if(sensors[1] < 100 && sensors[2] < 100 && sensors[3] < 100)
+        {
+            // There is no line visible ahead, and we didn't see any
+            // intersection.  Must be a dead end.
+            foundjunction=1;
+        }
+        else if(sensors[0] > 200 || sensors[4] > 200)
+        {
+            // Found an intersection.
+            foundjunction=1;
+        }
+       } 
+     } 
+
+
+}
+
+// This function decides which way to turn during the learning phase of
+// maze solving.  It uses the variables found_left, found_straight, and
+// found_right, which indicate whether there is an exit in each of the
+// three directions, applying the "left hand on the wall" strategy.
+
+char turn(unsigned char found_left, unsigned char found_forward, unsigned char found_right)
+{
+    // The order of the statements in this "if" is sufficient to implement a follow left-hand wall algorithm
+    if(found_left)
+        return 'L';
+    else if(found_forward)
+        return 'F';
+    else if(found_right)
+        return 'R';
+    else
+        return 'B';
+}
+
+void doturn(unsigned char dir)
+{
+    if (dir=='L')
+        {m3pi.left(0.25);wait(0.28);}   
+     else if(dir=='R')
+      {m3pi.right(0.25);wait(0.28);}  
+    else if(dir=='F')
+      {m3pi.forward(0.3);wait(0.15);}
+     else if(dir=='B')
+      {m3pi.right(0.25);wait(0.6);}
+       
+        return;
+}
+
+// change LBL to S (etc), to bypass dead ends
+void simplify()
+{
+    // only simplify the path if the second-to-last turn was a 'B'
+    if(path_length < 3 || path[path_length-2] != 'B')
+        return;
+
+
+    int total_angle = 0;
+    int i;
+    for(i=1;i<=3;i++)
+    {
+        switch(path[path_length-i])
+        {
+        case 'R':
+            total_angle += 90;
+            break;
+        case 'L':
+            total_angle += 270;
+            break;
+        case 'B':
+            total_angle += 180;
+            break;
+        }
+    }
+
+    // Get the angle as a number between 0 and 360 degrees.
+    total_angle = total_angle % 360;
+
+    // Replace all of those turns with a single one.
+    switch(total_angle)
+    {
+    case 0:
+        path[path_length - 3] = 'F';
+        break;
+    case 90:
+        path[path_length - 3] = 'R';
+        break;
+    case 180:
+        path[path_length - 3] = 'B';
+        break;
+    case 270:
+        path[path_length - 3] = 'L';
+        break;
+    }
+
+    // The path is now two steps shorter.
+    path_length -= 2;
+}
+
+// This function is called once, from main.c.
+void mazesolve()
+{
+    // These variables record whether the robot has seen a line to the    
+    // left, straight ahead, and right, while examining the current
+    // intersection.
+        unsigned char found_left=0;
+        unsigned char found_forward=0;
+        unsigned char found_right=0;
+    int sensors[5];
+    // Loop until we have solved the maze.
+    while(1)
+    {
+    
+        // Follow the line until an intersection is detected
+        follow_line();
+
+        // Inch forward a bit.  This helps us in case we entered the
+        // intersection at an angle.
+         m3pi.forward(0.1);
+         wait(0.07);
+        found_left=0;found_forward=0;found_right=0;
+    
+        
+        // Now read the sensors and check the intersection type.
+
+ 
+      
+        m3pi.forward(0.0);    
+      
+        // Check for a forward exit.
+        m3pi.readsensor(sensors);
+        if(sensors[1] > 200 || sensors[2] > 200 || sensors[3] > 200)
+            found_forward = 1;
+        
+               m3pi.readsensor(sensors);
+
+        // Check for left and right exits.
+        if(sensors[0] > 100)
+            found_left = 1;
+        if(sensors[4] > 100)
+            found_right = 1;
+        
+        //debug code
+        m3pi.cls();
+        if (found_left==1)
+           m3pi.printf("L");
+        if (found_right==1)
+           m3pi.printf("R");
+        if (found_forward==1)
+           m3pi.printf("F");
+       // wait (2);
+        // Check for the ending spot.
+        // If all five sensors are on dark black, we have
+        // solved the maze.
+       if(sensors[0] > 310 && sensors[1] > 310 && sensors[2] > 310 && sensors[3] > 310&& sensors[4] > 310)
+      
+            break;
+ 
+        // Drive straight a bit more - this is enough to line up our
+        // wheels with the intersection.
+        
+
+        unsigned char dir = turn(found_left, found_forward, found_right);
+
+        // Make the turn indicated by the path.
+        doturn(dir);
+
+        // Store the intersection in the path variable.
+        path[path_length] = dir;
+        path_length ++;
+
+        // Need to insert check to make sure that the path_length does not
+        // exceed the bounds of the array.  
+
+        // Simplify the learned path.
+        simplify();
+
+    }
+
+    // Solved the maze!
+
+    // Now enter an infinite loop - we can re-run the maze as many
+    // times as we want to.
+    while(1)
+    {
+
+        m3pi.forward(0.0);
+        m3pi.printf("Finished");
+
+    // wait 15s to give time to turn off, or put the robot back to the start
+    wait(15);
+    // ideally we would use a button press here       
+    // but I don't think it can easily be read
+
+        // Re-run the maze.  It's not necessary to identify the
+        // intersections, so this loop is really simple.
+        int i;
+        for(i=0;i<path_length;i++)
+        {
+             
+            follow_line();
+
+            // Drive straight while slowing down
+            m3pi.forward(0.3);
+            wait(0.1);
+
+            // Make a turn according to the instruction stored in
+            // path[i].
+            doturn(path[i]);
+        }
+        
+        // Follow the last segment up to the finish.
+        follow_line();
+
+        // Now we should be at the finish!  Restart the loop.
+    }
+}
+
+ void checksensors()
+{
+int sensors[5];
+while (1) {
+      m3pi.readsensor(sensors);
+        m3pi.cls();
+        if (sensors[0]>200)
+           m3pi.printf("D");
+           else  m3pi.printf("L");
+        if (sensors[1]>200)
+           m3pi.printf("D");
+           else  m3pi.printf("L");     
+             if (sensors[2]>200)
+           m3pi.printf("D");
+           else  m3pi.printf("L");
+             if (sensors[3]>200)
+           m3pi.printf("D");
+           else  m3pi.printf("L");
+             if (sensors[4]>200)
+           m3pi.printf("D");
+           else  m3pi.printf("L");
+    }
+}
+int main() {
+  
+    m3pi.locate(0,1);
+    m3pi.sensor_auto_calibrate();
+    m3pi.printf("MazeSolve");
+
+    wait(2.0);
+
+  mazesolve();
+
+m3pi.forward(0.0);
+
+}
diff -r 000000000000 -r df7d60d7a6ee mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Apr 12 14:37:54 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e
diff -r 000000000000 -r df7d60d7a6ee sharp_pid.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sharp_pid.lib	Thu Apr 12 14:37:54 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/Tomas/code/SHARPIR/#323d66022af5