File content as of revision 0:26c09c4aba81:

#include "mbed.h"
#include "math.h"
#include "Glowing.h"

Glowing::Glowing(PinName pin, float period, int steps, int offset) {
    // Set the constants
    s_port          = new PwmOut(pin);
    s_steps         = steps;
    s_step_offset   = offset;
    c_circle        = 2*acos(-1.0);    // 2 PI
    c_step_time     = period/steps;
    c_step_gradient = c_circle/steps;
    s_running       = false;
}

Glowing::~Glowing() {
    Stop();
}

int Glowing::scale(float x) {
    // Scaling the input value from [-1.0 - 1.0] to [0 - 1000]
    return (int)((x + 1.0)*1000/2);
}
void Glowing::next(void) {
    // Set the PWM value
    s_port->pulsewidth_us(s_next_v);
    // Calculate the next step and the corresponding PWM value
    s_next_n  = (s_next_n + 1) % s_steps;
    s_next_v  = scale(cos(s_next_n * c_step_gradient));
}

void Glowing::Start(void) {
    s_port->period_ms(1);
    s_next_v = 0.0;
    s_next_n = s_steps/2 + s_step_offset;
    attach(this, &Glowing::next, c_step_time);
    s_running = true;
}

void Glowing::Stop(void) {
    if (s_running) {
        detach();
    }
}