PID

def PID(Kp, Ki, Kd, setpoint, current_value, last_error, last_time):
    error = setpoint - current_value
    integral = integral + (error*dt)
    derivative = (error - last_error)/dt
    output = Kp*error + Ki*integral + Kd*derivative
    last_error = error
    last_time = time
    return (output, integral, derivative, last_error, last_time)