/*!
* \brief LineSensor::getValues get state of all 21 line sensors
*
* This function reads the line sensor values, and compares them to LINE_THRESHOLD
* defined in `linesensor.h`. If a value is lower than the threshold, it is
* considered to be over the line (the line is dark), and has the value `true`,
* otherwise it's `false`.
* \see SimComm::read
* \return bool array of sensor values
*/
QVarLengthArray<bool>
LineSensor::getValues()
{
QVarLengthArray<bool> vals;
for(quint8 i=0;i<21;i++)
vals.append(false);
// check for value in cache
std::shared_ptr<QVarLengthArray<bool>> cvalues = this->cachevalues.lock();
if(cvalues)
{
// use cached value
vals = *cvalues;
}
else
{
// read new values
QString raw = this->read();
if(raw.length() < 100)
return vals;
QStringList rawValues = raw.split(QRegExp("\\s"));
if(rawValues.size() < 21)
return vals;
for(quint8 i=0;i<rawValues.size();i++)
if(i<vals.size())
vals.replace(i, rawValues[i].toFloat() < LINE_THRESHOLD);
// cache values
this->pvalues = std::make_shared<QVarLengthArray<bool>>(vals);
this->cachevalues = this->pvalues;
this->start_cache_timer(); // will reset cache 70ms later
}
return vals;
}
