File content as of revision 3:e888f52a46bc:

#include "mbed.h"
#include "MODSERIAL.h"
#include "encoder.h"
#include "math.h"
#include "HIDScope.h"

//HIDScope scope(1);
MODSERIAL pc(USBTX,USBRX);
PwmOut speed1(D5);
DigitalOut dir1(D4);
DigitalOut led1(D8);
DigitalOut led2(D11);
AnalogIn pot(A1);
DigitalIn button1(D13);
DigitalIn button2(D12);
Ticker potmeterreadout;
Ticker encoderreadout;
Ticker Frequency;
Encoder motor1(PTD0,PTC4);

float PwmPeriod = 0.0001f;

double count = 0; //set the counts of the encoder
volatile double angle = 0;//set the angles

double setpoint = 6.28;//I am setting it to move through 180 degrees
double Kp = 250;// you can set these constants however you like depending on trial & error
double Ki = 100;
double Kd = 0;

float last_error = 0;
float error1 = 0;
float changeError = 0;
float totalError = 0;
float pidTerm = 0;
float pidTerm_scaled = 0;// if the total gain we get is not in the PWM range we scale it down so that it's not bigger than |255|

volatile double potvalue = 0.0;
volatile double position = 0.0;



/*void readpot()
{

}
*/
void PIDcalculation()
{
    potvalue = pot.read();
    angle = motor1.getPosition()/4200.00*6.28;
    setpoint = potvalue*6.28f;
    //pc.printf("pos: %d, speed %f reference position = %.2f\r ",motor1.getPosition(), motor1.getSpeed(), setpoint);
    //motorpid = PID(potvalue - position, M1_KP, M1_KI, M1_KD, M1_TS, m1_err_int, m1_prev_err, m1_f_v1, m1_f_v2, M1_F_A1, M1_F_A2, M1_F_B0, M1_F_B1, M1_F_B2);



    error1 = setpoint - angle;

    changeError = (error1 - last_error)/0.001f; // derivative term
    totalError += error1*0.001f; //accumalate errors to find integral term
    pidTerm = (Kp * error1) + (Ki * totalError) + (Kd * changeError);//total gain
    pidTerm = pidTerm;
    if (pidTerm >= 1000) {
        pidTerm = 1000;
    } else if (pidTerm <= -1000) {
        pidTerm = -1000;
    } else {
        pidTerm = pidTerm;
    }
    //constraining to appropriate value
        if (pidTerm >= 0) {
        dir1 = 1;// Forward motion
    } else {
        dir1 = 0;//Reverse motion
    }
    pidTerm_scaled = abs(pidTerm)/1000.0f; //make sure it's a positive value
    if(pidTerm_scaled >= 0.55f){
        pidTerm_scaled = 0.55f;
    }
        
    last_error = error1;
    speed1 = pidTerm_scaled+0.45f;
}
/*
void ReadOut()
{
   scope.set(0,angle);
   scope.send(); 
}
*/

int main()
{
    encoderreadout.attach(PIDcalculation,0.01f);
    speed1.period(PwmPeriod);
    
    int count = 0;
    while(true) {
        
        count++;
        if(count == 100){
            count = 0;
            pc.printf("Angle = %f, pidTerm = %f ,PID_scaled = %f, Error = %f, setpoint = %f\r\n", angle, pidTerm ,pidTerm_scaled, error1,setpoint);
        }
        
        wait(0.001f);
    }

}