AVRFreaks.net

#define GET_SENSOR_STATE(SENSOR_NUMBER) qt_measure_data.qt_touch_status.sensor_states[(SENSOR_NUMBER/8)] & (1 << (SENSOR_NUMBER % 8))


static volatile uint16_t current_time_ms_touch = 0u;
/* Timer period in msec. */
uint16_t qt_measurement_period_msec = 25u;
/* flag set by timer ISR when it's time to measure touch */
static volatile uint8_t time_to_measure_touch = 0u;


ISR(TIMER1_OVF_vect)
{
   // Reinitialize Timer1 value
   TCNT1H=0x6D84 >> 8;
   TCNT1L=0x6D84 & 0xff;
   /*  set flag: it's time to measure touch    */
   time_to_measure_touch = 1u;

   /*  update the current time */
   current_time_ms_touch += qt_measurement_period_msec;
}



int main(void)
{
   /*status flags to indicate the re-burst for library*/
   static uint16_t status_flag = 0u;
   static uint16_t burst_flag = 0u;

   //enable led
   DDRC |= _BV(7);
   
   
   /* Configure the Sensors as keys or Keys With Rotor/Sliders in this function */
   config_sensors();

   /* initialize touch sensing */
   qt_init_sensing();

   /*  Set the parameters like recalibration threshold, Max_On_Duration etc in this function by the user */
   qt_set_parameters( );
   /* configure timer ISR to fire regularly */
   /*  set timer compare value (how often timer ISR will fire) */
   // Timer/Counter 1 initialization
   // Clock source: System Clock
   // Clock value: 1500.000 kHz
   // Mode: Normal top=0xFFFF
   // OC1A output: Discon.
   // OC1B output: Discon.
   // Noise Canceler: Off
   // Input Capture on Falling Edge
   // Timer1 Overflow Interrupt: On
   // Input Capture Interrupt: Off
   // Compare A Match Interrupt: Off
   // Compare B Match Interrupt: Off
   TCCR1A=0x00;
   TCCR1B=0x02;
   TCNT1H=0x6D;
   TCNT1L=0x84;
   ICR1H=0x00;
   ICR1L=0x00;
   OCR1AH=0x00;
   OCR1AL=0x00;
   OCR1BH=0x00;
   OCR1BL=0x00;
   // Timer(s)/Counter(s) Interrupt(s) initialization
   TIMSK=0x04;
 /*  Address to pass address of user functions   */
    /*  This function is called after the library has made capacitive measurements,
    *   but before it has processed them. The user can use this hook to apply filter
    *   functions to the measured signal values.(Possibly to fix sensor layout faults)    */
    qt_filter_callback = 0;
   qt_config_data.qt_di = 2;
   sei();
   while(1)
    {
        if( time_to_measure_touch )
        {

           /*  clear flag: it's time to measure touch  */
           time_to_measure_touch = 0u;

           do {
              /*  one time measure touch sensors    */
              status_flag = qt_measure_sensors( current_time_ms_touch );
             
              burst_flag = status_flag & QTLIB_BURST_AGAIN;
              if (burst_flag!= 0u)
              {
                
                 /*Time critical host application code goes here*/
                
              }
             
              else
              {
                 if(GET_SENSOR_STATE(0))
                 {
                    PORTC &= ~_BV(7);

                 }
                 else
                 {
                    PORTC |= _BV(7);
                 }
              }
           }while (  burst_flag) ;

      
      
      }         
    }
}


static void qt_set_parameters( void )
{
    /*  This will be modified by the user to different values   */
    qt_config_data.qt_di              = DEF_QT_DI;
    qt_config_data.qt_neg_drift_rate  = DEF_QT_NEG_DRIFT_RATE;
    qt_config_data.qt_pos_drift_rate  = DEF_QT_POS_DRIFT_RATE;
    qt_config_data.qt_max_on_duration = DEF_QT_MAX_ON_DURATION;
    qt_config_data.qt_drift_hold_time = DEF_QT_DRIFT_HOLD_TIME;
    qt_config_data.qt_recal_threshold = DEF_QT_RECAL_THRESHOLD;
    qt_config_data.qt_pos_recal_delay = DEF_QT_POS_RECAL_DELAY;
}


static void config_sensors(void)
{
  qt_enable_key( CHANNEL_0, AKS_GROUP_1, 4u, HYST_6_25 );
}