File content as of revision 33:5477deb3803e:

#include "mbed.h"
#include "HIDScope.h"
#include "MODSERIAL.h"
#include "biquadFilter.h"
#include "QEI.h"
#include "math.h"
#include <string> 

/*--------------------------------------------------------------------------------------------------------------------
-------------------------------- BIOROBOTICS GROUP 14 ----------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

//Define important constants in memory
#define     PI              3.14159265
#define     SAMPLE_RATE     0.002   //500 Hz EMG sample rate
#define     CONTROL_RATE    0.01    //100 Hz Control rate
#define     ENCODER1_CPR    4200    //encoders have 64 (X4), 32 (X2) counts per revolution of motor shaft
#define     ENCODER2_CPR    4200    //gearbox 1:131.25 ->  4200 counts per revolution of the output shaft (X2), 
#define     PWM_PERIOD      0.0001  //10k Hz pwm motor frequency. Higher -> too hot, lower -> motor doesnt respond correctly
/*--------------------------------------------------------------------------------------------------------------------
---- OBJECTS ---------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

MODSERIAL pc(USBTX,USBRX);      //serial communication

//Debug LEDs
DigitalOut red(LED_RED);
DigitalOut green(LED_GREEN);
DigitalOut blue(LED_BLUE);


Ticker      sample_timer;       //Ticker for EMG sampling
Ticker      control_timer;      //Ticker for control loop
HIDScope    scope(4);           //Scope 4 channels

// AnalogIn potmeter(A4);       //potmeters
// AnalogIn potmeter2(A5);      //

//Encoders 
QEI Encoder1(D13,D12,NC,32);    //channel A and B from encoder, counts = Encoder.getPulses();
QEI Encoder2(D10,D9,NC,32);     //channel A and B from encoder, 

//Speed and Direction of motors - D4 (dir) and D5(speed) = motor 2, D7(dir) and D6(speed) = motor 1
PwmOut pwm_motor1(D6);          //PWM motor 1
PwmOut pwm_motor2(D5);          //PWM motor 2

DigitalOut dir_motor1(D7);      //Direction motor 1
DigitalOut dir_motor2(D4);      //Direction motor 2

//Limit Switches
InterruptIn shoulder_limit(D2);  //using FRDM buttons 
InterruptIn elbow_limit(D3);     //using FRDM buttons

//Other buttons
DigitalIn button1(PTA4);        //using FRDM buttons 
DigitalIn button2(PTC6);        //using FRDM buttons



/*--------------------------------------------------------------------------------------------------------------------
---- DECLARE VARIABLES -----------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/


//PID variables
double u1; double u2;                                               //Output of PID controller (PWM value for motor 1 and 2)
double m1_error=0; double m1_e_int=0; double m1_e_prev=0;           //Error, integrated error, previous error
const double m1_kp=0.01; const double m1_ki=0.00125; const double m1_kd=0.00;   //Proportional, integral and derivative gains.

double m2_error=0; double m2_e_int=0; double m2_e_prev=0;           //Error, integrated error, previous error
const double m2_kp=0.01; const double m2_ki=0.00125; const double m2_kd=0.00;   //Proportional, integral and derivative gains.


//lowpass filter 7 Hz  - envelope
const double low_b0 = 0.000119046743110057;
const double low_b1 = 0.000238093486220118;
const double low_b2 = 0.000119046743110057;
const double low_a1 = -1.968902268531908;
const double low_a2 = 0.9693784555043481;

//Forward Kinematics
const double l1 = 0.25; const double l2 = 0.25;
double current_x; double current_y;
double theta1; double theta2;
double dtheta1; double dtheta2;
double rpc;
double x=0.5; double y=0;
double x_error; double y_error;
double costheta1; double sintheta1;
double costheta2; double sintheta2;
/*--------------------------------------------------------------------------------------------------------------------
---- Filters ---------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

//Using biquadFilter library
//Syntax: biquadFilter     filter(a1, a2, b0, b1, b2); coefficients. Call with: filter.step(u), with u signal to be filtered.

//PID filter (lowpass ??? Hz)
biquadFilter     derfilter( low_a1 , low_a2 , low_b0 , low_b1 , low_b2 );   // derivative filter 
biquadFilter     derfilter2( low_a1 , low_a2 , low_b0 , low_b1 , low_b2 ); 
/*--------------------------------------------------------------------------------------------------------------------
---- DECLARE FUNCTION NAMES ------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/


void control();             //Control - reference -> error -> pid -> motor output


void calibrate_arm(void);   //Calibration of the arm with limit switches
void start_sampling(void);  //Attaches the sample_filter function to a 500Hz ticker
void stop_sampling(void);   //Stops sample_filter
void start_control(void);   //Attaches the control function to a 100Hz ticker
void stop_control(void);    //Stops control function

//Keeps the input between min and max value
void keep_in_range(double * in, double min, double max);

//Reusable PID controller, previous and integral error need to be passed by reference
double pid(double error, double kp, double ki, double kd,double &e_int, double &e_prev);
double pid2(double error, double kp, double ki, double kd,double &e_int, double &e_prev);

//Menu functions
void mainMenu();
void caliMenu();
void clearTerminal();
void controlMenu();

/*--------------------------------------------------------------------------------------------------------------------
---- MAIN LOOP -------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

volatile bool looptimerflag;

void setlooptimerflag(void)
{
    looptimerflag = true;
} 

int main()
{
    pc.baud(115200);            //terminal baudrate
    red=1; green=1; blue=1;     //Make sure debug LEDS are off  
    
    //Set PwmOut frequency to 10k Hz???
    pwm_motor1.period(0.0001);    
    pwm_motor2.period(0.0001);
    
    
    //VARIABLES
    AnalogIn potmeter(A4);
    AnalogIn potmeter2(A5);
    //DigitalIn button(D8);
    //MODSERIAL pc(USBTX,USBRX);
    
    //Encoder motor1(D13,D12);   // channel A and B from encoder, true - getSpeed works
    //PwmOut pwm_motor1(D6);          // D4 and D5 = motor 2, D7 and D6 = motor 2  
    //DigitalOut dir_motor1(D7);      // 
    
    //Encoder motor2(D10,D9);   // channel A and B from encoder, true - getSpeed works
   // PwmOut pwm_motor2(D5);          // D4 and D5 = motor 2, D7 and D6 = motor 2  
   // DigitalOut dir_motor2(D4);      // 
    
    // MOTOR1
    double goal;
    double pwm_to_motor;  
    // MOTOR2
    double goal2;
    double pwm_to_motor2;  
        
    //CODE
    pc.baud(115200);
    
    //pwm_motor1.write(0.2f);         // Speed
    //dir_motor1.write(1);            // Direction
   
    Ticker looptimer;
    looptimer.attach(setlooptimerflag,0.01);  

    while (1) {
        
        while(looptimerflag != true);
        looptimerflag = false;
        
        //MOTOR1
        goal = (potmeter.read()-0.5)*4200;
        //pc.printf("setpoint: %f, %d, %f \n\r", goal, motor1.getPosition(),motor1.getSpeed());
        double error1 = (goal - Encoder1.getPulses());
        pwm_to_motor = pid(error1,m1_kp,m1_ki,m1_kd,m1_e_int,m1_e_prev); 
    
        if(pwm_to_motor > 0)
            dir_motor1 = 1;     //=clockwise
        else
            dir_motor1 = 0;     //=counterclockwise
        
        pwm_motor1.write(abs(pwm_to_motor));
        
        //MOTOR2
        goal2 = (potmeter2.read()-0.5)*4200;
        
        double error2=(goal2 - Encoder2.getPulses());
        pwm_to_motor2 = pid(error2,m2_kp,m2_ki,m2_kd,m2_e_int,m2_e_prev);
    
        if(pwm_to_motor2 > 0)
            dir_motor2 = 0;         //=counterclockwise
        else
            dir_motor2 = 1;         //=clockwise
        
        pwm_motor2.write(abs(pwm_to_motor2));
        //pc.printf("setpoint: %f, %d, %f \n\r", goal2, motor2.getPosition());   
    
       
    pc.printf("goal: %f, pulses: %d \n\r", goal, Encoder1.getPulses());  
    pc.printf("goal2: %f, pulses2: %d \n\r", goal2, Encoder2.getPulses());
    
    }
    //end of while loop
}
//end of main

/*--------------------------------------------------------------------------------------------------------------------
---- FUNCTIONS -------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/


//Send arm to mechanical limits, and set encoder to 0. Then send arm to starting position.
void calibrate_arm(void)
{
    pc.printf("Calibrate_arm() entered\r\n");
    bool calibrating = true;
    bool done1 = false;
    bool done2 = false;
    pc.printf("To start arm calibration, press any key =>");
    pc.getc();
    pc.printf("\r\n Calibrating... \r\n");
    dir_motor1=1;   //cw
    dir_motor2=0;   //cw
    pwm_motor1.write(0.2);     //move upper arm slowly cw
    
   
    
    while(calibrating){
        red=0; blue=0;              //Debug light is purple during arm calibration
        
        if(done1==true){
            pwm_motor2.write(0.2);     //move forearm slowly cw
        }
        
        //when limit switches are hit, stop motor and reset encoder
        if(shoulder_limit.read() < 0.5){   //polling 
            pwm_motor1.write(0);
            Encoder1.reset();
            done1 = true;
            pc.printf("Shoulder Limit hit - shutting down motor 1\r\n");
        }
        if(elbow_limit.read() < 0.5){     //polling
            pwm_motor2.write(0);
            Encoder2.reset();
            done2 = true;
            pc.printf("Elbow Limit hit - shutting down motor 2. \r\n");
        }    
        if(done1 && done2){
            calibrating=false;      //Leave while loop when both limits are reached
            red=1; blue=1;          //Turn debug light off when calibration complete
        }
   
    }//end while
    
    //TO DO:
    //mechanical angle limits -> pulses. If 40 degrees -> counts = floor( 40 / (2*pi/4200) )
    //Encoder1.setPulses(100);       //edited QEI library: added setPulses()
    //Encoder2.setPulses(100);       //edited QEI library: added setPulses()
    //pc.printf("Elbow Limit hit - shutting down motor 2. Current pulsecount: %i \r\n",Encoder1.getPulses());
    wait(1);
    pc.printf("Arm Calibration Complete\r\n");
}


//Input error and Kp, Kd, Ki, output control signal
double pid(double error, double kp, double ki, double kd,double &e_int, double &e_prev)
{
    // Derivative
    double e_der = (error-e_prev)/ CONTROL_RATE;
    e_der = derfilter.step(e_der);
    e_prev = error;
    // Integral
    e_int = e_int + CONTROL_RATE * error;
    // PID
    return kp*error + ki*e_int + kd * e_der;
    
}

double pid2(double error, double kp, double ki, double kd,double &e_int, double &e_prev)
{
    // Derivative
    double e_der = (error-e_prev)/ CONTROL_RATE;
    e_der = derfilter2.step(e_der);
    e_prev = error;
    // Integral
    e_int = e_int + CONTROL_RATE * error;
    // PID
    return kp*error + ki*e_int; //+ kd * e_der;
    
}

void controlMenu()
{
     pc.printf("1) Move Arm Left\r\n");
     pc.printf("2) Move Arm Right\r\n");
     pc.printf("3) Move Arm Up\r\n");
     pc.printf("4) Move Arm Down\r\n");
     pc.printf("q) Exit \r\n");
     pc.printf("Please make a choice => \r\n");
}



//Analyze filtered EMG, calculate reference position from EMG, compare reference position with current position,convert to angles, send error through pid(), send PWM and DIR to motors 
void control()
{
                                                                
    //Current position - Encoder counts -> current angle -> Forward Kinematics 
    rpc=(2*PI)/ENCODER1_CPR;               //radians per count (resolution) - 2pi divided by 4200
    theta1 = Encoder1.getPulses() * rpc;   //multiply resolution with number of counts
    theta2 = Encoder2.getPulses() * rpc;
    current_x = l1 * cos(theta1) + l2 * cos(theta1 + theta2);
    current_y = l1 * sin(theta1) + l2 * sin(theta1 + theta2);
    
    //pc.printf("Calculated current position: x = %f and y = %f \r\n",current_x,current_y);
    
    
    //pc.printf("X is %f and Y is %f \r\n",x,y);
        
    //calculate error (refpos-currentpos) currentpos = forward kinematics
    x_error = x - current_x;
    y_error = y - current_y;
    
    //pc.printf("X error is %f and Y error is %f \r\n",x_error,y_error);
    
    //inverse kinematics (refpos to refangle)
    
    costheta2 = (pow(x,2) + pow(y,2) - pow(l1,2) - pow(l2,2)) / (2*l1*l2) ;
    sintheta2 = sqrt( 1 - pow(costheta2,2) );
     
    //pc.printf("costheta2 = %f and sostheta2 = %f \r\n",costheta2,sostheta2);
    
    dtheta2 = atan2(sintheta2,costheta2);
    
    costheta1 = ( x * (l1 + l2 * costheta2) + y * l2 * sintheta2 ) / ( pow(x,2) + pow(y,2) );
    sintheta1 = sqrt( 1 - pow(costheta1,2) );
    
    //pc.printf("costheta1 = %f and sostheta1 = %f \r\n",costheta1,sostheta1);
    
    dtheta1 = atan2(sintheta1,costheta1);
    
    
    //Angle error
    
    m1_error = dtheta1-theta1;
    m2_error = dtheta2-theta2;
    
    //pc.printf("m1 error is %f and m2 error is %f \r\n",m1_error,m2_error);
    
    //PID controller
    
    u1=pid(m1_error,m1_kp,m1_ki,m1_kd,m1_e_int,m1_e_prev);    //motor 1
    u2=pid(m2_error,m2_kp,m2_ki,m2_kd,m2_e_int,m2_e_prev);    //motor 2
    
    keep_in_range(&u1,-0.6,0.6);    //keep u between -1 and 1, sign = direction, PWM = 0-1
    keep_in_range(&u2,-0.6,0.6);
    
    //send PWM and DIR to motor 1
    dir_motor1 = u1>0 ? 1 : 0;          //conditional statement dir_motor1 = [condition] ? [if met 1] : [else 0]], same as if else below. 
    pwm_motor1.write(abs(u1));
    
    //send PWM and DIR to motor 2
    dir_motor2 = u2>0 ? 0 : 1;          //conditional statement, same as if else below
    pwm_motor2.write(abs(u2));
    
    
    //       } //if
   //} //while
    
    
    /*if(u1 > 0)
    {
        dir_motor1 = 0;
    else{
        dir_motor1 = 1;
        }
    }    
    pwm_motor1.write(abs(u1));
    
  
    if(u2 > 0)
    {
        dir_motor1 = 1;
    else{
        dir_motor1 = 0;
        }
    }    
    pwm_motor1.write(abs(u2));*/
    
}

void mainMenu()
{
   //Title Box
   pc.putc(201); 
   for(int j=0;j<33;j++){
   pc.putc(205);
   }
   pc.putc(187); 
   pc.printf("\n\r");
   pc.putc(186); pc.printf("    BioRobotics M9 - Group 14    "); pc.putc(186);
   pc.printf("\n\r");
   pc.putc(186); pc.printf("         Robot powered ON        "); pc.putc(186);
   pc.printf("\n\r");
   pc.putc(200);
   for(int k=0;k<33;k++){
   pc.putc(205);
   }
   pc.putc(188); 
   
   pc.printf("\n\r");
   //endbox
}
void caliMenu(){};



//Start control
void start_control(void)
{
    control_timer.attach(&control,0.01);     //100 Hz control
    
    //Debug LED will be blue when control is on. If sampling and control are on -> blue + green = cyan.
    blue=0;
    pc.printf("||- started control -|| \r\n");
}

//stop control
void stop_control(void)
{
    control_timer.detach();
    
    //Debug LED will be off when control is off
    blue=1;
    pc.printf("||- stopped control -|| \r\n");
}


void calibrate()
{

}

//Clears the putty (or other terminal) window
void clearTerminal()
{
   pc.putc(27); 
   pc.printf("[2J"); // clear screen 
   pc.putc(27); // ESC 
   pc.printf("[H"); // cursor to home 
}

//keeps input limited between min max
void keep_in_range(double * in, double min, double max)
{
    *in > min ? *in < max? : *in = max: *in = min;
}