File content as of revision 2:8887d13f967a:

#include "mbed.h"
#include "LSM9DS1.h"
#include "rtos.h"
//#include "SDFileSystem.h"
#include "Motor.h"
//#include "wave_player.h"

#define PI 3.14159
// Earth's magnetic field varies by location. Add or subtract
// a declination to get a more accurate heading. Calculate
// your's here:
// http://www.ngdc.noaa.gov/geomag-web/#declination
#define DECLINATION -4.94 // Declination (degrees) in Atlanta,GA.
//collab test

Serial pc(USBTX, USBRX);
//RawSerial  pc(USBTX, USBRX);
Serial dev(p28,p27);    // 
//RawSerial  dev(p28,p27); //tx, rx
DigitalOut myled(LED1);
DigitalOut led2(LED2);
DigitalOut led3(LED3);
DigitalOut led4(LED4);
//IR sensors on p19(front) & p20 (right)
AnalogIn IR1(p19);
AnalogIn IR2(p20);
//L and R DC motors
Motor Left(p21, p14, p13);      // green wires. pwm, fwd, rev, add ", 1" for braking
Motor Right(p22, p12, p11);     // red wires
// Speaker out
AnalogOut DACout(p18);      //must(?) be p18
//SDFileSystem sd(p5, p6, p7, p8, "sd"); //SD card
Thread thread1;
Thread thread2;
Mutex BTmutex;                  //mutex for send/recv data on Bluetooth
Mutex mutex;                    //other mutex for global resources

//Globals
float throttle = 0.3;
float currIR1;
float currIR2;
float origHeading;
float heading;

// Calculate pitch, roll, and heading.
// Pitch/roll calculations taken from this app note:
// http://cache.freescale.com/files/sensors/doc/app_note/AN3461.pdf?fpsp=1
// Heading calculations taken from this app note:
// http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/Magnetic__Literature_Application_notes-documents/AN203_Compass_Heading_Using_Magnetometers.pdf
void printAttitude(float ax, float ay, float az, float mx, float my, float mz)
{   //entire subroutine is BTmutexed already
    float roll = atan2(ay, az);
    float pitch = atan2(-ax, sqrt(ay * ay + az * az));
    // touchy trig stuff to use arctan to get compass heading (scale is 0..360)
    mx = -mx;
    //float heading;        //turning to global
    if (my == 0.0) {
        mutex.lock();
        heading = (mx < 0.0) ? 180.0 : 0.0;
        mutex.unlock();
    }
    else {
        mutex.lock();
        heading = atan2(mx, my)*360.0/(2.0*PI);
        mutex.unlock();
    }
    //pc.printf("heading atan=%f \n\r",heading);
    mutex.lock();
    heading -= DECLINATION; //correct for geo location
    if(heading>180.0) heading = heading - 360.0;
    else if(heading<-180.0) heading = 360.0 + heading;
    else if(heading<0.0) heading = 360.0  + heading;
    mutex.unlock();
    // Convert everything from radians to degrees:
    //heading *= 180.0 / PI;
    pitch *= 180.0 / PI;
    roll  *= 180.0 / PI;
    //~pc.printf("Pitch: %f,    Roll: %f degress\n\r",pitch,roll);
    //~pc.printf("Magnetic Heading: %f degress\n\r",heading);
    dev.printf("Magnetic Heading: %f degrees\n\r",heading); 
}

/*
void dev_recv()
{
    led2 = !led2;
    while(dev.readable()) {
        pc.putc(dev.getc());
    }
}
void pc_recv()
{
    led4 = !led4;
    while(pc.readable()) {
        dev.putc(pc.getc());
    }
}*/

    // Driving Methods
void forward(float speed){
    Left.speed(speed);
    Right.speed(speed);    
}
void reverse(float speed){
    Left.speed(-speed);
    Right.speed(-speed);
}
void turnRight(float speed){
    Left.speed(speed);
    Right.speed(-speed);
    //wait(0.7);
}
void turnLeft(float speed){
    Left.speed(-speed);
    Right.speed(speed);
    //wait(0.7);
}
void stop(){
    Left.speed(0.0);
    Right.speed(0.0);
}

void IMU(){
    //IMU setup
    LSM9DS1 IMU(p9, p10, 0xD6, 0x3C);   // this executes. Pins are correct. Changing them causes fault
    IMU.begin();           
    if (!IMU.begin()) {    
        led2=1;
        pc.printf("Failed to communicate with LSM9DS1.\n");
    }
    IMU.calibrate(1);
    IMU.calibrateMag(0);
    /*
    //bluetooth setup
    pc.baud(9600);
    dev.baud(9600); */
    /*pc.attach(&pc_recv, Serial::RxIrq);
    dev.attach(&dev_recv, Serial::RxIrq);*/
    while(1) {
        //myled = 1;
        while(!IMU.magAvailable(X_AXIS));
        IMU.readMag();
        //myled = 0;
        while(!IMU.accelAvailable());
        IMU.readAccel();
        while(!IMU.gyroAvailable());
        IMU.readGyro();
        BTmutex.lock();
        pc.puts("        X axis    Y axis    Z axis\n\r");
        //dev.puts("        X axis    Y axis    Z axis\n\r");
        pc.printf("gyro:  %9f %9f %9f in deg/s\n\r", IMU.calcGyro(IMU.gx), IMU.calcGyro(IMU.gy), IMU.calcGyro(IMU.gz));
        pc.printf("accel: %9f %9f %9f in Gs\n\r", IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az));
        pc.printf("mag:   %9f %9f %9f in gauss\n\r", IMU.calcMag(IMU.mx), IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
        //dev.printf("mag:   %9f %9f %9f in gauss\n\r", IMU.calcMag(IMU.mx), IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
        printAttitude(IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az), IMU.calcMag(IMU.mx),
                      IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
        BTmutex.unlock();
        //myled = 1;
        wait(0.5);
        //myled = 0;
        wait(0.5);   
    }  
}

void avoidObstacle(){
    currIR1 = IR1;        //get IR readings
    currIR2 = IR2;
    //if(currIR1 > 0.8){
    stop();
    Thread::wait(300);
    BTmutex.lock();
    //dev.printf("Collision Detected!\n\r");
    BTmutex.unlock();
    //dev.printf("Turning Left...\n\r");
    turnLeft(0.4);          //turn 90deg
    Thread::wait(1000);      //time to turn estimate
    /*
    while(IR2 < 0.7){           //turn left until IR2 detects an object.
        currIR2 = IR2;
        Thread::wait(300);
    }   */
    stop();
    Thread::wait(1000);
    // turn should be complete. Drive until obstacle passed on right, then turn right again
    //BTmutex.lock();
    //dev.printf("Driving past obstacle.\n\r");
    //BTmutex.unlock();
    forward(throttle);
    bool objOnRight = true;
    while(objOnRight){
        currIR1 = IR1;
        currIR2 = IR2;
        if(currIR2 < 0.7){ objOnRight = false;} //if IR2 drops below threshold, obstacle passed. Break out of loop
        Thread::wait(250);
    }
    stop();
    Thread::wait(250);
    BTmutex.lock();
    //dev.printf("Object passed. Turning right...\n\r");
    turnRight(0.4);     // turn 90deg
    Thread::wait(1000);      //time to turn estimate
    stop();
    Thread::wait(1000);
    forward(throttle);    
        
    //}
}

void defaultDrive(){        //default behavior for robot
    //Drive forward until object detected. Stop, turn left, then drive until IR2 says path is clear, then turn right to go around object.
    forward(throttle);
    while(1){
        //update current IR readings
        currIR1 = IR1;
        currIR2 = IR2;
        BTmutex.lock();         //prevent race conditions in BT dataoutput
        //dev.puts("      Front IR reading    Right IR reading\n\r");     // print IR readings over BT 
        //dev.printf("        %2f             %2f\n\r", currIR1, currIR2);
        BTmutex.unlock();
        // Forward collision handling code block
        if(currIR1 > 0.8) {     // 0.85 is threshold for collision
            avoidObstacle();    // steer around obstacle when detected
            
            /*PICK UP FROM HERE
              Implement logic to control two scenarios:
              1) Roomba has detected obstacle in front, but Right is clear. 
            */
                        
        }    
        Thread::wait(400);      // for debug. IR polling too quick and floods output terminal
    }
}

void manualMode(){
    bool on = true;
    char temp;
    while(on){
        temp = dev.getc();
        if(temp == 'A'){  // reset command
            on = false;
        }
        else if(temp=='U'){
            led2=led3=1;
            forward(throttle);
            wait(1);
            led2=led3=0;
        }
        else if(temp=='L'){  // turn left
            myled=led2=1;   //debug
            stop();
            wait(0.3);
            turnLeft(0.4);
            wait(0.6);
            stop();
            wait(0.3);
            forward(throttle);
            myled=led2=0;   //debug
        }
        else if(temp=='R'){  // turn right
            led3=led4=1;
            stop();
            wait(0.3);
            turnRight(0.4);
            wait(0.6);
            stop();
            wait(0.3);
            forward(throttle);
            led3=led4=0;
        }
        else if(temp=='X'){  // halt/brake command
            stop();
        }
        //myled=1;
        //wait(0.5);
        //myled=0;
        //wait(0.5);
    }
}

int main()
{
    //bluetooth setup
    pc.baud(9600);
    dev.baud(9600);
    //wait to recv start command
    
    for(int i=0; i<3;i++){          //temp delay for a few sec
        myled=led2=led3=led4=1;
        wait(0.5);
        myled=led2=led3=led4=0;
        wait(0.5);
    }   
    thread1.start(IMU); // start the IMU thread
    char temp;
    /*
    while(1){   //robot will receive a char from GUI signalling time to start
        temp = dev.getc();
        led3=1;
        pc.putc(temp);
        if (temp == 'B'){
            break;
        }
        
        if(led2 == 0) led2 = 1;
        else {led2 = 0;}
        wait(0.25);
    }   
    */
    led3=0;
    thread2.start(defaultDrive);
    while(1){
        temp = dev.getc();
        if(temp == 'M'){
            led4=1;
            stop();
            thread2.terminate();     //stop default drive
            manualMode();       //switch to manual control
            //once manualMode is exited, return to default
            led4=0;
            thread2.start(defaultDrive);
        }
    }
    
}