File content as of revision 2:3161f535d71a:

#include "mbed.h"
#include "Quadcopter.h"
#include "PID.h"
#include "MPU6050.h"
#include "Timer.h"

#define MAX_CALIBRATE 1.0
#define MIN_CALIBRATE 0.35

#define FL   0    // Front left    
#define FR   1    // Front right
#define BL   2    // back left
#define BR   3    // back right

#define OFFSET_SAMPLES 50
//define how the accelerometer is placed on surface
#define X_AXIS 1
#define Y_AXIS 2
#define Z_AXIS 0

#define MAX_CALIBRATE 1.0
#define MIN_CALIBRATE 0.35

#define FL   0    // Front left    
#define FR   1    // Front right
#define BL   2    // back left
#define BR   3    // back right

#define PITCH_IN_MIN -90.0
#define PITCH_IN_MAX 90.0
#define PITCH_OUT_MIN -0.5
#define PITCH_OUT_MAX 0.5

#define ROLL_IN_MIN -90.0
#define ROLL_IN_MAX 90.0
#define ROLL_OUT_MIN -0.5
#define ROLL_OUT_MAX 0.5

#define Kc 0.1
#define Ti 0.1
#define Td 0.0
#define RATE 0.01
//--------------------------------ALL THE FUNCTION HEADERS-----------------------
float map(float x, float in_min, float in_max, float out_min, float out_max);
//---------------------------------------END-------------------------------------

Quadcopter quad (p21, p22, p23, p24);
Serial pc(USBTX, USBRX); // tx, rx
MPU6050 mpu(p9, p10);   //Also disables sleep mode
Timer timer;

//Kc, Ti, Td, interval
PID pitchPID (Kc, Ti, Td, RATE);
PID rollPID (Kc, Ti, Td, RATE);

//***************************************STARTING MAIN FUNCTION*********************
int main() {
    pc.baud (115200);
    
    float pitchDiff;
    float rollDiff;
    
    float speed[4];
    float actSpeed[4];
    
    float accOffset[3]; //offset values
    float gyroOffset[3];
    float angle[3];     //total calculated angle

    float currTime;
    float prevTime;
    
    if (mpu.testConnection())   //just testing if things are working...
        pc.printf("MPU connection succeeded\n\r");
    else
        pc.printf("MPU connection failed\n\r");
    
    mpu.setAlpha(0.97);     //set Alpha coefficient for low/high pass filters
    
    quad.calibrate(MIN_CALIBRATE, MAX_CALIBRATE);   //calibrating motors
    
    pitchPID.setInputLimits (PITCH_IN_MIN, PITCH_IN_MAX);   //seting input and output limits for both pitch and roll
    pitchPID.setOutputLimits (PITCH_OUT_MIN, PITCH_OUT_MAX);

    rollPID.setInputLimits (ROLL_IN_MIN, ROLL_IN_MAX);
    rollPID.setOutputLimits (ROLL_OUT_MIN, ROLL_OUT_MAX);
    
    pitchPID.setMode(AUTO_MODE);    //start stabilising by puting AUTO mode
    rollPID.setMode(AUTO_MODE);
    
    //need to vary this one to move quadcopter
    pitchPID.setSetPoint (0.0); //seting the middle point.. Or smth like that, need to look into it more
    rollPID.setSetPoint (0.0);  //meaning that quadcopter is flying at a constant place.. no turning, blah blah blah

    mpu.getOffset(accOffset, gyroOffset, OFFSET_SAMPLES); //take some samples at the beginning to get an offset
    wait(0.1);                //wait to settle down
    
    timer.start();  //will need timer to detect when was the last time the values were updated
    prevTime = timer.read();
    
    for (int i = 0; i < 4; i++){
        speed[i] = 0.0;
    }
//-------------------------------------------START INFINITE LOOP-------------------------------------------------
    while(1) {
//        for (float height = 0.0; height < 0.5; height+=0.05){
//            for (int i = 0; i < 4; i++){
//                speed[i] = height;
//            }
//            quad.run (speed);
//            wait(0.1);
//        }
//        for (uint16_t i = 0; i < 600; i++)
//        {
            currTime = timer.read();    //get present time
            mpu.computeAngle (angle, accOffset, gyroOffset, &currTime, &prevTime); // get angle using all these values
            
            rollPID.setInterval(timer.read()-prevTime);         //need to change the interval because don't know how much time passed
            pitchPID.setInterval(timer.read()-prevTime);
            
            prevTime = timer.read();    //get present time -> will be used later on as previous value
        
            rollPID.setProcessValue (angle[X_AXIS]);    //take some values to do processing
            pitchPID.setProcessValue (angle[Y_AXIS]);
        
            pitchDiff = pitchPID.compute();     //compute the difference
            rollDiff = rollPID.compute();
        
            quad.stabilise(speed, actSpeed, rollDiff, pitchDiff);   //stabilise the speed by giving new actSpeed value
            
            //print some values to check how thing work out
     //       pc.printf("x=%0.3f y=%0.3f z=%0.3f\n", angle[X_AXIS], angle[Y_AXIS], angle[Z_AXIS]);
            pc.printf("Speed_FL=%0.4f, Speed_FR=%0.4f, Speed_BL= %0.4f, Speed_BR=%0.4f\n", speed[FL], speed[FR], speed[BL], speed[BR]);
            pc.printf("ActSpeed_FL=%0.4f, ActSpeed_FR=%0.4f, ActSpeed_BL=%0.4f, ActSpeed_BR=%0.4f\n", actSpeed[FL], actSpeed[FR], actSpeed[BL], actSpeed[BR]);
            
     //       quad.run(actSpeed); //run the motors at the spesified speed actSpeed
            
            wait (0.01);
//        }
        
//        for (float height = 0.5; height > 0.0; height-=0.05){
//            for (int i = 0; i < 4; i++){
//                speed[i] = height;
//            }
//            quad.run (speed);
//            wait(0.1);
//        }
//        wait(1);
    }
}
//************************************************END MAIN FUNCTION********************************************************

//-----------------------------Mapping function-----------------------------
float map(float x, float in_min, float in_max, float out_min, float out_max){
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}