File content as of revision 0:42272569c45a:

#include "mbed.h"
#include "MODSERIAL.h"
#define SERIAL_BAUD 115200
#include "QEI.h"
#include "HIDScope.h"

MODSERIAL pc(USBTX, USBRX);
QEI Encoder(D12,D13,NC,64,QEI::X4_ENCODING);
DigitalOut motor1_direction(D4);
PwmOut motor1_pwm(D5);
InterruptIn button1(D2);
AnalogIn potmeter1(A0);

HIDScope scope(1);
Ticker scopeTimer;

const float timer = 0.01;
const float timer1 = 0.1;
const float countspr = 8400;
const float max_velocity = 8.4;
const float pi = 3.14159265359;
int counts;
int counts_p;
int pwmvalue;
float potmeter;
float angle;
float referencevelocity;
float velocity;

void print(){
    pc.printf("%i\r\n", counts);
    pc.printf("velocity: %3.3f%\n", velocity);
    pc.printf("angle: %3.3f%\n", angle);
}

void flipdirection()    {
    motor1_direction = !motor1_direction;
}

void controlmotor()    {
    potmeter = potmeter1.read();
    referencevelocity = potmeter*max_velocity;
    motor1_pwm.pulsewidth(referencevelocity/max_velocity*0.020);
}

void calculateangle()   {
    angle = fmod(counts,countspr)/countspr*2*pi;
}

void derivative()   {
    velocity = (counts-counts_p)/countspr*2*pi/timer;
    counts_p = counts;
}

void scopeSend()
{
    scope.set(0,velocity);
    scope.send();
}
    
int main()
{
    motor1_direction = 1;
    pc.baud(SERIAL_BAUD);
    Ticker time;
    Ticker time1;
    Ticker time2;
    Ticker time3;
    time.attach(print, timer1);
    time1.attach(controlmotor, timer);
    time2.attach(calculateangle, timer);
    time3.attach(derivative, timer);
    button1.rise(&flipdirection);
    
    scopeTimer.attach_us(&scopeSend, 1e4);
    motor1_pwm.period(0.020f); // set pwm period to 20ms
    while (true) {
        counts = Encoder.getPulses();
    }
}