Ultrasonic sensor range detection

Forum 2005-2010 (read only) Software Syntax & Programs
1

Hi,

I would like to detect some object on different levels during different elapsed times.

What's the best way to do that ?

Thank you

2

I would like to detect some object on different levels

Is there some context for this? What different levels are you talking about?

during different elapsed times.

Using millis() and a start time? Or is there some other meaning to "different elapsed times"?

3

levels are
0 to 20 cm : level1
20 to 40 cm : level2
40 to 60 cm : level3
60 to infinite : level4

This is my code for instant:

void FunctionalTasks::set_m_currentDist()
{
    //
    SRF02::update();
    m_currentDist = _UltraSonicPtr->read();
    String str =  String(m_currentDist);
    str.concat("cm");
    _Tracer->LcdPrintTopLineFromRightFast(str);

    // check
    if ( m_currentDist < 200 )
    {
        startSensorChrono();
    }
}

void FunctionalTasks::set_m_startTime_ultrasonic ( unsigned long pm_startTime_ultrasonic ) 
{
    m_startTime_ultrasonic=pm_startTime_ultrasonic;
}
unsigned long FunctionalTasks::get_m_startTime_ultrasonic () 
{
    return m_startTime_ultrasonic;
}

void FunctionalTasks::startSensorChrono()
{
    //
    if( m_startTime_ultrasonic==0)
    {
        _idxTab=0;
        set_m_startTime_ultrasonic(millis());
    }
    else
    {
        checkSensorChrono();
        feedDistanceSamples();
    }
}
void FunctionalTasks::checkSensorChrono()
{
    //
    if( m_startTime_ultrasonic==0)
    {
        set_m_startTime_ultrasonic(millis());
    }
}
void FunctionalTasks::feedDistanceSamples()
{
    if ( _idxTab <_MAX_DIST_SAMPLES )
    {
        _tab[_idxTab]=get_m_currentDist();
        _idxTab++;
    }
    else
    {
        _idxTab=0;
    }
}